Dissertations / Theses: 'Bacillus (bacteria)'

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Lampe, Karen Rippere. "Molecular Systematics of the Entomopathogenic Bacteria Bacillus popilliae, Bacillus lentimorbus, and Bacillus sphaericus." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30717.

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Bacillus popilliae and B. lentimorbus, causative agents of milky disease in Japanese beetles and related scarab larvae, have been differentiated based upon a small number of phenotypic characteristics, but they have not previously been examined at the molecular level. Thirty-four isolates of these bacteria were examined for DNA similarity. Three distinct but related similarity groups were identified; the first contained strains of B. popilliae, the second contained strains of B. lentimorbus, and the third contained two strains distinct from but related to B. popilliae. Some strains received as B. popilliae were found to be most closely related to B. lentimorbus and some received as B. lentimorbus were found to be most closely related to B. popilliae." Geographically distinct strains of B. popilliae and B. lentimorbus were analyzed using RAPD. Eight decamer primers were tested against nineteen new and seventeen isolates previously described by randomly amplified polymorphic DNA (RAPD) analysis (M. Tran). Of the new isolates, ten were found to be B. popilliae while nine isolates were more related to the B. lentimorbus species. Paraspore formation, believed to be a characteristic unique to B. popilliae, was found to occur among a subgroup of B. lentimorbus strains. Using a combination of two PCR primer pairs, the cry18Aa1 gene was detected in 31 of 35 B. popilliae isolates and in 1 of 18 B. lentimorbus isolates. When hemolymph smears were examined microscopically, a parasporal crystal was seen in three of the four B. popilliae strains where the PCR primers could not amplify the paraspore gene. The fourth strain was not tested due to the unavailability of infected hemolymph. A paraspore was also detected by microscopic examination in a subgroup of 14 B. lentimorbus strains. In combination, the primer pairs CryBp1 and CryBp2 are effective at detecting the paraspore gene in B. popilliae isolates, but not in the B. lentimorbus isolates. Growth in media supplemented with 2% NaCl was found to be less reliable in distinguishing the species than was vancomycin resistance, the latter present only in B. popilliae. The basis for vancomycin resistance in all isolates was investigated using a polymerase chain reaction assay designed to amplify the vanB gene in enterococci. An amplicon was identified and sequenced. The amplified portion of the putative ligase gene in B. popilliae had 77% and 68-69% nucleotide identity to the sequences of the vanA gene and the vanB genes, respectively. There was 75% and 69-70% identity between the deduced amino acid sequence of the putative ligase gene in B. popilliae and the deduced amino acid sequence of the vanA gene and the vanB genes, respectively. It has been determined that the vanE gene is located either on a plasmid greater than 16 kb in size or on the chromosome. The gene in B. popilliae may have had an ancestral gene in common with vancomycin resistance genes in enterococci. Bacillus sphaericus strains isolated on the basis of pathogenicity for mosquito larvae and strains isolated on the basis of a reaction with a B. sphaericus DNA homology group IIA 16S rRNA probe were analyzed for DNA similarity. All of the pathogens belonged to homology group IIA, but this group also contained nonpathogens. It appears inappropriate to designate this homology group a species based solely upon pathogenicity.
Ph. D.

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Contesini, Fabiano Jares. "Produção, caracterização e aplicação de proteases de Bacillus sp. = Production, characterization and application of proteases from Bacillus sp." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254357.

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Orientador: Hélia Harumi Sato
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Proteases bacterianas são enzimas de elevada importância comercial, amplamente aplicadas em diversas áreas como nas indústrias de detergentes, de alimentos, farmacêutica e têxtil. Este trabalho teve como principais objetivos selecionar entre 59 linhagens de Bacillus sp., da coleção de culturas do Laboratório de Bioquímica de Alimentos da FEA, aquelas que apresentam potencial de maior produção de proteases com características tais como estabilidade em diferentes condições de temperatura, pH, detergentes e solventes orgânicos, atividade em ampla faixa de pH e capacidade de lisar células de Xanthomonas campestris. Em seguida, visou-se otimizar a produção de proteases pela linhagem selecionada, determinar as características bioquímicas da protease parcialmente purificada e estudar a aplicação do extrato enzimático bruto e preparação parcialmente purificada. Entre as cinquenta e nove linhagens de Bacillus sp. testadas foram selecionadas nove linhagens que produziram maior atividade de proteases. A produção de protease pelas nove linhagens foi testada em frascos agitados contendo o meio de cultura nº 1 (10g/L de caseína, 1g/L de extrato de levedura e sais), meio nº 2 (35 g/L de melaço de cana de açúcar, 20g/L de água de maceração de milho, 3g/L de extrato de levedura Prodex-Lac SD® e 20g/L de soro de queijo), e por fermentação em meio sólido nº 3 (farelo de trigo e água, na proporção 1:1, m:m). As linhagens de Bacillus sp. LBA 07, Bacillus sp. LBA 46 e Bacillus sp. LBA 08 fermentadas nos meios de cultura nº 1, nº 2 e nº 3 produziram 222 U/mL, 548 U/mL e 13480 U/grama de substrato seco (gss) respectivamente. As proteases dos extratos enzimáticos brutos obtidos das nove linhagens fermentadas nos três meios de cultura apresentaram atividade ótima na faixa de pH 7 a 9 e 60° C, estabilidade na faixa de pH 5 a 9 por 24h a 4º C , e após 1 h de tratamento a 50° C. Entre os extratos enzimáticos brutos de proteases testados, aqueles obtidas da fermentação de Bacillus sp. LBA 46 nos três meios de cultura foram as mais estáveis em detergente Ariel®. Quando incubadas em solventes orgânicos alguns extratos enzimáticos brutos proteases mantiveram mais de 60% de atividade residual após 24h em acetona (Bacillus sp. LBA 8 e 44), hexano (Bacillus sp. LBA 19, 29, 44, 46 e 60), clorofórmio (Bacillus sp. LBA 44 and 60) e etanol (Bacillus sp. LBA 60). Os extratos enzimáticos brutos de proteases obtidos do cultivo da linhagem de Bacillus sp. LBA 46 nos meios n° 2 e n° 3 foram as mais eficientes na lise de células de Xanthomonas campestris, aumentando cerca de 30% a transmitância a 620 nm (Trans 620nm) do meio fermentado de goma xantana. A linhagem de Bacillus sp. LBA 46 foi selecionada como melhor produtora de protease e estudos preliminares de identificação biomolecular indicam que se trata de uma linhagem de Bacillus licheniformis. Utilizando-se a linhagem de Bacillus sp LBA 46 e o meio de cultura otimizado (meio n° 4) por metodologia de superfície de resposta (MSR), composto de 40g/L de melaço de cana de açúcar, 6g/L de água de maceração de milho, 2g/L de extrato de levedura Prodex-Lac SD® e 20g/L de soro de queijo, foi obtido 3000 U/mL de protease após 96h de fermentação a 30° C e 200 rpm. No estudo da aplicação da enzima para a remoção de manchas de tecidos de algodão foram obtidos melhores resultados de remoção de manchas de sangue e molho de tomate com carne moída, utilizando-se a combinação de extrato bruto de protease (100 ou 1000U) com o detergente Omo®. O extrato enzimático bruto da linhagem de Bacillus sp. LBA 46 foi parcialmente purificado por fracionamento com sulfato de amônio (80% de saturação), diálise e cromatografia de filtração em gel (Sephadex G100), resultando em fator de purificação de 3,69. Após caracterização com MSR observou-se que a protease da preparação parcialmente purificada apresentou atividade ótima a 55° C e pH 7,5 e considerável estabilidade (95% de atividade residual) na faixa de pH 5,7 ¿ 9,3 após 1h de incubação a 30 ¿ 36° C, e acima de 78,9% quando incubadas por 1h em pH 7,5 e 50° C. A condição ótima de lise das células de X. campestris do meio fermentado de goma xantana utilizando-se o extrato enzimático bruto de protease e a preparação parcialmente purificada de proteases, foi observada utilizando 42 U de protease /mL de suspensão celular de X. campestris a 60° C, resultando em aumento de mais de 20% da Trans 620nm do meio fermentado de goma xantana. Um aumento de quase 40% de Trans 600nm foi observado após 2h de reação utilizando extrato enzimático bruto de protease (42 U de protease/mL de suspensão celular de X. campestris) a 65° C. A produção de proteases de Bacillus sp. LBA 46 por fermentação em estado sólido foi otimizada utilizando MSR, sendo obtido 5000 U/grama de substrato seco utilizando-se meio de cultura composto de farelo de trigo e água (60%:40%) após 96h de fermentação a 30° C
Abstract: Proteases are commercially relevant enzymes widely applied in several industrial areas, such as in detergent, food, pharmaceutical and textile industries. Proteases from Bacillus sp. can present advantages compared to the proteases from other sources, including better thermostability, stability in pH range from slightly acid to alkaline pH values and stability in organic solvents. The aims of this work were selecting Bacillus sp. strains with capability of producing proteases with better biochemical properties, such as stability in different conditions of temperature, pH, detergents and organic solvents, activity in a wide range of pH and capability of lysing cells of Xanthomonas campestris. Afterwards, it was aimed the optimization of the production of proteases by the selected Bacillus sp. strain and the determination of the biochemical characteristics of the partially purified protease and the application of the crude and partially purified protease. Nine Bacillus sp. strains were selected as the best protease producers among fifty nine Bacillus sp. strains tested. The protease production by the nine strains was carried out in Erlenmeyer flasks containing medium no. 1 (10g /L of casein, 1g/L of yeast extract and salts), medium no. 2 (35 g/L of sugar cane molasses, 20g/L corn steep liquor, 3g/L of yeast extract Prodex-Lac SD® and 20g/L of dried whey), e by fermentation using solid substrate medium no. 3 (wheat bran and water, 1:1, m:m). The strains Bacillus sp. LBA 07, Bacillus sp. LBA 46 and Bacillus sp. LBA 08 when fermented in medium no. 1, no. 2 e no. 3 produced 222 U/mL, 545 U/mL and 13480 U/gram of dried substrate (gds) respectively. Proteases from the crude enzymatic extracts obtained from the fermentation of the nine Bacillus sp. strains in the three media showed optimal activity in pH range 7-9 and 60° C, stability in pH range 5-9 for 24 hours at 4° C and after 1h at 50° C. The protease preparations from the fermentation of Bacillus sp. LBA 46 in the three media were the most stable when incubated in detergent Ariel®, among the proteases tested from the Bacillus sp. strains. In addition, some proteases presented more than 60% residual activity after 24h in the organic solvents acetone (Bacillus sp. LBA 8 and 44), hexane (Bacillus sp. LBA 19, 29, 44, 46 and 60), chloroform (Bacillus sp. LBA 44 and 60) and ethanol (Bacillus sp. LBA 60). The protease preparations obtained from the cultivation of Bacillus sp. LBA 46 in medium no. 2 and no. 3 presented the best results on the lysis of Xanthomonas campestris cells, resulting in an increase of approximately 30% in transmittance at 620 nm (Trans 620nm) of the fermented broth of xanthan. Bacillus sp. LBA 46 strain was selected as the best protease producer and after preliminary biomolecular analysis of identification, the results indicate that this microorganism correspond to a Bacillus licheniformis strain. Protease preparation containing 3000 U/mL was obtained from Bacillus sp. LBA 46 cultivated in Erlenmeyer flasks containing medium no. 4 composed of 40g/L of sugar cane molasses, 6g/L of corn steep liquor, 2g/L of yeast extract Prodex-Lac SD® and 20 g/L of dried whey after 96h of fermentation at 30° C and 200 rpm, optimized with response surface methodology (RSM). In the the washing tests, the best results of the removal of blood and tomato sauce with ground beef stains from cotton fabrics were observed using the combination of crude extract of protease (100 or 1000U) with detergent Omo®. Crude protease extract of the Bacillus sp. LBA strain was partially purified by ammonium sulfate fractionation (80% saturation), dialysis and gel filtration chromatography (Sephadex G100), resulting in the purification fold of 3.69. After characterization with RSM it was observed that the crude protease extract and partially purified proteases presented optimal activity at 55° C and pH 7.5 and considerable stability (95% of residual activity) in pH range 5.7 ¿ 9.3 after 1h incubation at 30-36° C and more than 78.9% when incubated at pH 7.5 and 50 °C for 1h. The optimal conditions of the lysis of X. campestris cells contained in the fermentation broth using crude and partially purified protease preparations were observed using 42 U of protease/mL of cell suspension of X. campestris at 60° C, resulting in a increase of more than 20% in Trans 620 nm of the fermented broth of xanthan. It was observed an increase of almost 40% in Trans 620 nm after 2h reaction using crude protease (42 U de protease/mL of cell suspension of X. campestris) at 65° C. The production of proteases by Bacillus sp. LBA 46 under solid state fermentation was optimized using RSM, resulting in 5000 U/gram of dry substrate utilizing wheat bran and water (6g:4g) after 96h of fermentation at 30° C
Doutorado
Ciência de Alimentos
Doutor em Ciência de Alimentos

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Reeves, Adam J. "Signaling and interaction of the Bacillus subtilis physical stress pathway regulators of sigma B : a dissertation /." San Antonio : UTHSC, 2007. http://proquest.umi.com/pqdweb?did=1390290691&sid=1&Fmt=2&clientId=70986&RQT=309&VName=PQD.

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Johansson, Per. "Genetics of tetrapyrrole synthesis in gram-positive bacteria." Lund : Lund University, 1999. http://catalog.hathitrust.org/api/volumes/oclc/68944808.html.

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Gumbo, Jabulani Ray. "Antagonism of Bacillus spp. towards Microcyctis aeruginosa." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-04102008-113241/.

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Thesis (PhD Microbiology and Plant Pathology(Water resource management))-University of Pretoria, 2006.
Summary in English. Includes bibliographical references. Available on the Internet via the World Wide Web.

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Sebastião, Isis [UNESP]. "Toxicidade e interação de proteínas Cry1 de Bacillus thuringiensis em Helicoverpa armigera (Hübner) (Lepidóptera: Noctuidae)." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/123869.

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Estudos que visam a interação das proteínas Cry de Bacillus thuringiensis, a fim de encontrar combinações adequadas para o desenvolvimento de plantas Bt são ferramentais fundamentais no controle de lepidópteros-praga. A lagarta H. armigera causa danos severos nas culturas agrícolas e sua introdução no Brasil levou a busca de formas de controle eficientes e nesse contexto B. thuringiensis pode ser um bom agente de controle. Diante do exposto o presente trabalho objetivou avaliar a toxicidade das proteínas Cry1Aa, Cry1Ab, Cry1Ac e Cry1Ca de B. thuringiensis à H. armigera, assim como interação dessas proteínas aos receptores do mesêntero do inseto. A toxicidade foi estimada com bioensaios de dose resposta com as proteínas testadas e a interação das proteínas com os receptores foram verificadas em análise de união entre a proteína ativada e marcada com a vesícula da borda em escova da membrana apical das células do intestino (brush border mambrane vesicle- BBMV) do mesêntero larval de H. armigera, e ensaios de competição heteróloga. Dentre as proteínas testadas, a Cry1Ac destacou-se como a mais efetiva, seguida das proteínas Cry1Ab e Cry1Aa. A proteína Cry1Ca não apresentou toxicidade. As proteínas Cry1Aa, Cry1Ab e Cry1Ac se ligaram aos receptores da membrana do intestino médio das lagartas de H. armigera de forma especifica. Os ensaios de competição heteróloga revelaram que as proteínas Cry1Aa, Cry1Ac e Cry1Ab competem entre si pelo mesmo receptor
Studies attempting interaction of Bacillus thuringiensis Cry proteins in order to find combinations for developing Bt plants are fundamental in controlling lepidopteran pests. H. armigera causes severe damage to agricultural crops and their introduction in Brazil has led the search for efficient control and B. thuringiensis may be a good control agent. The aim of this research was to evaluate the toxicity of Cry1Aa, Cry1Ab, Cry1Ac and Cry1Ca proteins from B. thuringiensis to H. armigera, as well as interaction of these proteins with the receptors present in insect midgut. Toxicity was estimated from the lethal concentration LC50 of the tested proteins and protein interactions with the receptors were found in a binding analysis between activated and biotinylated protein with the midgut brush border vesicle membrane (BBMV) of H. armigera, and heterologous competitive binding assays. Among the tested proteins, Cry1Ac protein was the most toxic, followed by the Cry1Ab and Cry1Aa proteins. The Cry1Ca protein showed no toxicity. The Cry1Aa, Cry1Ab and Cry1Ac proteins showed specific binding to the midgut membrane receptors of H. armigera caterpillars. Heterologous competitive binding assays revealed that Cry1Aa, Cry1Ab, Cry1Ac compete for a common receptor in the midgut larvae

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Sebastião, Isis. "Toxicidade e interação de proteínas Cry1 de Bacillus thuringiensis em Helicoverpa armigera (Hübner) (Lepidóptera: Noctuidae) /." Jaboticabal, 2015. http://hdl.handle.net/11449/123869.

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Orientador: Manoel Victor Franco Lemos
Coorientador: Ricardo Antonio Polanczyk
Banca: Janete Apparecida Desidério
Banca: Camila Chiaradia Davolos
Resumo: Estudos que visam a interação das proteínas Cry de Bacillus thuringiensis, a fim de encontrar combinações adequadas para o desenvolvimento de plantas Bt são ferramentais fundamentais no controle de lepidópteros-praga. A lagarta H. armigera causa danos severos nas culturas agrícolas e sua introdução no Brasil levou a busca de formas de controle eficientes e nesse contexto B. thuringiensis pode ser um bom agente de controle. Diante do exposto o presente trabalho objetivou avaliar a toxicidade das proteínas Cry1Aa, Cry1Ab, Cry1Ac e Cry1Ca de B. thuringiensis à H. armigera, assim como interação dessas proteínas aos receptores do mesêntero do inseto. A toxicidade foi estimada com bioensaios de dose resposta com as proteínas testadas e a interação das proteínas com os receptores foram verificadas em análise de união entre a proteína ativada e marcada com a vesícula da "borda em escova" da membrana apical das células do intestino ("brush border mambrane vesicle"- BBMV) do mesêntero larval de H. armigera, e ensaios de competição heteróloga. Dentre as proteínas testadas, a Cry1Ac destacou-se como a mais efetiva, seguida das proteínas Cry1Ab e Cry1Aa. A proteína Cry1Ca não apresentou toxicidade. As proteínas Cry1Aa, Cry1Ab e Cry1Ac se ligaram aos receptores da membrana do intestino médio das lagartas de H. armigera de forma especifica. Os ensaios de competição heteróloga revelaram que as proteínas Cry1Aa, Cry1Ac e Cry1Ab competem entre si pelo mesmo receptor
Abstract: Studies attempting interaction of Bacillus thuringiensis Cry proteins in order to find combinations for developing Bt plants are fundamental in controlling lepidopteran pests. H. armigera causes severe damage to agricultural crops and their introduction in Brazil has led the search for efficient control and B. thuringiensis may be a good control agent. The aim of this research was to evaluate the toxicity of Cry1Aa, Cry1Ab, Cry1Ac and Cry1Ca proteins from B. thuringiensis to H. armigera, as well as interaction of these proteins with the receptors present in insect midgut. Toxicity was estimated from the lethal concentration LC50 of the tested proteins and protein interactions with the receptors were found in a binding analysis between activated and biotinylated protein with the midgut brush border vesicle membrane (BBMV) of H. armigera, and heterologous competitive binding assays. Among the tested proteins, Cry1Ac protein was the most toxic, followed by the Cry1Ab and Cry1Aa proteins. The Cry1Ca protein showed no toxicity. The Cry1Aa, Cry1Ab and Cry1Ac proteins showed specific binding to the midgut membrane receptors of H. armigera caterpillars. Heterologous competitive binding assays revealed that Cry1Aa, Cry1Ab, Cry1Ac compete for a common receptor in the midgut larvae
Mestre

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Coxon, Rosemary D. "Factors affecting protein export from Bacillus subtilis." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287424.

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Helfinstine, Shannon L. "The Detection and Control of Bacillus Endospores." [Kent, Ohio] : Kent State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1176413118.

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Thesis (Ph.D.)--Kent State University, 2007.
Title from PDF t.p. (viewed Nov. 21, 2007). Advisor: Christopher J. Woolverton. Keywords: Bacillus, spores, electron beam irradiation, anthrax, liquid crystals, detection. Includes bibliographical references.

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Kaji, Denise Akiko. "Taxonomia molecular de Bacillus entomopatogenicos." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255729.

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Orientador : Vanderlei Perez Canhos
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Foi efetuado um estudo taxômico de 15 isolados entomopatogênicos de mostras de solos e insetos do Brasil com características de bactérias aeróbias, formadoras de endosporos e presença de cristal. Treze isolados acarretaram 100 % de mortalidade a larvas de Aedes fluviatilis em leituras observadas a 24 h. Os resultados dos testes de caracterização morfológica, bioquímica e fisiológica indicaram que 14 isolados pertencem a espécie Bacillus thuringiensis (B.t.) enquanto que o 15° foi determinado como Bacillus sphaericus (B.s.). Através dos perfis eletroforéticos de proteínas totais 11 B.t. isolados foram identificados como subespécie israelensis (sorotipo H-14, incluindo duas linhagens não sorotipadas), 1 como kurstaki (soro tipo H3a, 3b) e 1 como morT!isoni (sorotipo H8a, 8b). As linhagens de B. thuringiensis subsp. israelensis (B.t.i.) formaram um grupo homogêneo distinto das linhagens de referências tóxicas. a lepidópteros e coleópteros. O isolado identificado como B. sphaericus demonstrou alta similaridade com a linhagem 2362 através de testes de atividade larVicida; fagotipagem (fagotipo 3) e sorologia (H5). Os 11 isolados identificados como B.t.i. pela sorologia e/ou perfIS eletroforéticos de proteínas totais não apresentaram polimorflsmo quanto aos fragmentos de restrição, quando foram utilizadas sondas do gene 16S rRNA e do cristal de B.t.i.. A sonda do gene toxigêniro de B.t.i. demonstrou ser bastante específica para a subespécie israelensis, não apresentando hibridizaçóes Com outras subespécies. O gene do cristal de B.t.i. de referência IPS82 e isolados identificados como B.t.i. foram amplificados através da reação em cadeia da polimerase (PCR), digeridos com Sau3AI e separados por eletroforese. Os perfis de restrição destes fragmentos foram idênticos. Esses resultados indicam que os B.t.i. isolados no Brasil formam uni grupo. homogêneo e de organização genética bastante conservada. Outras 28 linhagens de referência representando 12 subespécies de B.t. com 9 sorotipos diferentes, 4 B. cereus e 4 B. anthracis foram incluídas na análise do perfil de hibridização com o gene 16S rRNA Os dados obtidos mostraram correspondência com os testes de sorologia (DE BARJAC & FRACHON, 1990) e a taxonomia numérica (PRIEST et ai., 1988)
Abstract: Fifteen bacterial isolates from Brazilian soil and insects with aerobic, endospores and crystal characteristics were taxonomically analysed. Thirteen strains were shown to be pathogenic to Aedes fluviatilis larvae causing 100 % mortality in 24 hours and two strains were non-pathogenic. The results of morphological, biochemical and physiological tests indicated that 14 strains belong B. thuringiensis (8.t.) while the remaining strain was identified as B. sphaericus. Electrophoresis ofwhole celI protein patterns helped in the identification of eleven isolates as israelensis (serotype H-14, including two non-serotypable strains), 1 as kurstaki (serotype H3a, 3b) and 1 as morrisoni (serotype H8a, 8b). Moreover, it was shown that alI B. thuringiensis subsp. israelensis (8.t.i.) strains. formed a homogenous group distinct from reference strains toxic for Lepidoptera or Coleoptera. The isolate identified as B. sphaericus presented high similarity with strain 2362 by larvicidal tests, phagotyping (group 3) and serotyping (H5). The is.olates identified as subspecies israelensis by serology and/or electrophoresis of whole cell proteins patterns showed the same patterns using restriction fragments length polymorphisms (RFLPs) analysis with the 16S rRNA and the crystal gene of B.t.i. as probes. The crystal gene of B.t.i. used as the probe was specific only to the subspecies israelensis. The crystal gene of B.t.i. reference (IPS82) and isolated strains of B.t.i. were amplified by Polymerase Chain Reaction (PCR), digested with Sau3AI and electrophoresed in agarose gel. The restriction fragment patterns obtained were identical. It confirmed as stated above that the B.t.i. isolates used in this study are a highly homogenous group with a conserva tive. genetic organization. Furthermore, 28B.t. reference strains representing 12 subspecies (with 9 different serotypes), 4 B. cereus and 4. B. anthracis were compared with regard to their ribosomal RNA gene restriction patterns. The results obtained match the serological tests (DEBARJAC & FRACHON, 1990) and numerical taxonomy studies (PRIEST et al., 1988). The results in this study suggest that the techniques could be an altemative to serological tests
Doutorado
Doutor em Ciência de Alimentos

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Socha, Aaron Martin. "Chemistry of antibiotics from Atlantic actinomycete and bacillus bacteria /." View online ; access limited to URI, 2008. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3346858.

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Fitzgerald, A. V. M. "Production of bacilysin by Bacillus subtilis." Thesis, University of Kent, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378626.

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Kimura, Giselle Kobata 1985. "Investigação do potencial celulolítico de bactérias oriundas de processo de compostagem." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316714.

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Orientadores: Fabiana Fantinatti Garboggini, Suzan Pantaroto de Vasconcellos
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Bactérias e fungos têm sido largamente explorados devido às suas habilidades em produzir uma grande variedade de enzimas, entre elas, as celulases que se destacam devido ao seu potencial em degradar materiais lignocelulósicos em açúcares fermentáveis, que podem então ser convertidos, por exemplo, em biocombustíveis. O presente trabalho visou a bioprospecção de bactérias isoladas a partir do processo de compostagem realizado pela Fundação Parque Zoológico de São Paulo (FPZSP), quanto à produção de enzimas celulolíticas, além da caracterização taxonômica das linhagens de interesse. Para tanto, os micro-organismos oriundos do processo de compostagem da FPZSP foram isolados, preservados e caracterizados macroscopicamente. Dentre as linhagens isoladas, 168 foram testadas numa triagem qualitativa para a produção de celulases, obtendo-se 135 micro-organismos com potencial celulolítico evidenciado pela formação de halos de hidrólise em meio de cultura contendo carboximetilcelulose. Destes, 10 linhagens apresentaram halos translúcidos com diâmetros entre 1,3 cm e 1,9 cm, as quais foram avaliadas quanto a atividade celulotíca em ensaios quantitativos monitorados durante 7 dias, em duas condições de pH distintas: 4,8 e 7,4. Os melhores tempos de incubação verificados foram de sete e cinco dias para os valores de pH 4,8 e 7,4, respectivamente. Em seguida, foram selecionados linhagens para os ensaios de delineamento experimental e otimização das atividades enzimáticas. No planejamento P&B, a melhor atividade celulolítica verificada foi de 3,6392 FPU/mL obtida a partir da linhagem FPZSP 143, no pH 4,8. Esta linhagem foi então selecionada e o planejamento do tipo Delineamento Composto Central Rotacional ¿ DCCR aplicado, promovendo dessa maneira, um aumento 0,4574 FPU/mL em relação ao experimento do planejamento anterior. Posteriormente, o experimento foi validado e o resultado máximo alcançado para atividade celulolítica da linhagem FPZSP 143 foi de 4,6435 FPU/mL. Cinco linhagens selecionadas com atividade celulolítica foram identificadas por análise de sequências do gene RNA ribossomal 16S como membros do gênero Bacillus, bactérias frequentemente encontradas em ambientes da compostagem e que tem sido largamente reportada como produtoras de enzimas celulolíticas. O processo de compostagem demonstrou ser um ambiente em potencial para a produção de celulases de interesse para diversos ramos da indústria, sendo os representantes do gênero Bacillus os melhores produtores de enzimas celulolíticas. Embora as bactérias tenham sido isoladas de um ambiente com pH em torno de 7,4, há um potencial para a produção de celulases em pH mais ácidos, evidenciando sua aplicabilidade em diferentes condições. Essa característica torna-se relevante quando se leva em consideração os processos industriais, onde uma condição diferente e específica é exigida em cada processo, tornando as enzimas celulolíticas oriundas de processo de compostagem grandes aliadas no desenvolvimento e otimização de processos industriais
Abstract: Bacteria and fungi have been extensively explored due to their ability to produce a variety of enzymes, including the cellulases that stand out because of their potential to degrade lignocellulosic materials to fermentable sugars, which can then be converted, for example, in biofuels. The present work aimed bioprospecting of bacteria isolated from the composting process conducted by Fundação Parque Zoológico de São Paulo (FPZSP), for the production of cellulolytic enzymes and the taxonomic characterization of strains of interest. For both, the microorganisms derived from the composting process of FPZSP were isolated, preserved and characterized macroscopically. Among the isolates, 168 were tested for production in a qualitative screening of cellulases, obtaining 135 cellulolytic microorganisms with potential evidenced by the formation of halos of hydrolysis in culture medium containing carboxymethylcellulose. These, 10 strains showed translucent halos with diameters between 1.3 cm and 1.9 cm, which were evaluated for activity in cellulolytic quantitative assays monitored for 7 days under two different pH conditions: 4.8 and 7.4. The best times of incubation recorded were seven and five days to pH 4.8 and 7.4, respectively. Then, strains for testing experimental design and optimization of enzymatic activities were selected. In Planning P&B, the best cellulolytic activity verified was 3.6392 FPU/mL obtained from FPZSP 143, at pH 4.8. This strain was selected and the DCCR applied, thus promoting an increase of 0.4574 FPU/mL compared to the previous experiment planning. Subsequently, the experiment was validated and the maximum score achieved for cellulolytic activity FPZSP 143 strain was 4.6435 FPU/mL. Five strains with cellulolytic activity were identified by sequence analysis of the 16S ribosomal RNA gene as members of the genus Bacillus, bacteria frequently encountered in composting environments and has been widely reported as producing cellulolytic enzymes. The composting process proved to be a potential environment for the production of cellulases of interest for various branches of industry, being the representatives of the genus Bacillus the best producers of cellulolytic enzymes. Although bacteria have been isolated from an environment with a pH around 7.4, there is a potential for the production of cellulases in more acidic pH, indicating their applicability in different conditions. This feature becomes important when one takes into account the industrial processes, where a different and specific condition is required in each case, making the cellulolytic enzymes derived from composting process a good allied in developing and industrial process optimization
Mestrado
Microbiologia
Mestra em Genética e Biologia Molecular

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Moraes, Regina de Oliveira. "Determinação da viabilidade de Bacillus Thuringiensis apos processos de secagem." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257391.

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Orientador: Kil Jin Park
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
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Resumo: Bacillus thurillgiellsis (Bt), uma bactéria utiJizada em controle biológico de lepidópteros, é produzida através de fermentação submersa ou semi-sólida . Após a fermentação um dos maiores problemas encontrados é a recuperação desse material. Neste trabalho foi estudada a secagem do material fermentado após centrifugação. A pasta foi pré-formulada usando 97% de argila como inerte e 3% de princípio ativo (Bt). A secagem foi feita usando diferentes tipos de secadores, nos quais se estabeleceram os parâmetros de interesse. A comparação entre os processos foi feita através da avaliação da manutenção da atividade microbiana de Bacillus thuringiellsis A secagem realizada em secador convencional a 90 Deapresentou um valor D de 5,86 h. A secagem realizada em atomizador a 120, 150 e 180 Deapresentou respectivamente 9,49 s, 5,88 s e 3,43 s de valor D, e valor z de 135,16 C.A viabilidade relativa foi mantida a 50De e 70De e sofreu redução a 90 De em secador convencional. No atomizador a viabilidade relativa decresceu com elevação da temperatura de 120 C a 180 C
Mestrado
Pre-Processamento de Produtos Agropecuarios
Mestre em Engenharia Agrícola

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Nakazato, Luciana Taba. "Influencia do palmitato de sacarose sobre o desenvolvimento de Bacillus stearothermophilus em extrato de cafe." [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255389.

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Orientador: Pilar Rodriguez de Massaguer
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Têm sido relatadas no exterior, principalmente no Japão, ocorrências de bactérias termófilas esporuladas produtoras de acidez plana em bebidas enlatadas a base de café vendidas a quente (50-60°C). A origem destes esporos estaria no extrato de café utilizado no preparo destas bebidas. Ácidos graxos esterificados com sacarose, como palmitato de sacarose por exemplo, possuem uma grande variedade de funções e propriedades, destacando-se o efeito emulsificante e antimicrobiano. Este estudo teve como objetivo avaliar sua atividade antimicrobiana em extrato de café frente a esporos de Bacillus stearothermophilus isolados de café solúvel. Para isso, uma suspensão de esporos foi preparada mediante esporulação em Caldo Nutriente acrescido de 1,5% de Ágar Nutriente e 5 ppm de MnSO4 seguida de coleta, limpeza e resuspensão dos esporos. Foram avaliadas várias concentrações de palmitato de sacarose (P-1570) entre 10-6000mg/l, produzido pela Mitsubishi Kagaku Foods Co., para ser determinada a Mínima Concentração Inibitória (MCI) no crescimento vegetativo de B. stearothermophilus em extrato de café. Após contagem realizada por plaqueamento em profundidade em meio de TSA (Trypitic Soy Agar - Difco), observou-se que 200 mg/l deste antimicrobiano já se mostrava eficaz na inibição do desenvolvimento de cerca de '10 POT. 4' esporos ativados por mI. Com base neste resultado, prosseguiu-se com a investigação do efeito do P-1570 frente a germinação de esporosde B.stearothermophilus. Os ensaios foram efetuados em Caldo Nutriente (CN pH 6,9), utilizando espectrofotômetro BECKMAN DU 640 ajustado para leitura de absorbância a um comprimento de onda de 590 nm. A partir da suspensão dos esporos diluída em CN pH 6,9 e ativada em água em ebulição pelo tempo ótimo de 20 minutos, a germinação e crescimento pós-germinativo foram acompanhadas durante 12 horas, na presença e ausência do P-1570, revelando uma baixa porcentagem de germinação nos dois tipos de amostra: 2,3; 3,7 e 2,8% com 100, 200 e 300 mg/l de P-1570, respectivamente, e 3,3% com O mg/l de P-1570. Não foi observado crescimento pósgerminativo na presença de 100,200 e 300 mg/l de P-1570. Finalmente, foi investigado o efeito do P-1570 sobre a resistência térmica dos esporos de B. stearothermophilus, a partir de uma suspensão de '10 POT. 6' esporos/mI de extrato de café, com 0 mg/l (controle) e 100 mg/l de P-1570, em tubos TDT. Os tubos TDT foram levados ao banho de óleo a 113, 115 e 118°C por diferentes tempos pré-determinados. ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital.
Abstract: Various canned coffee drinks have been distributed through vending machines at high temperatures (50 - 60°C), mainly in Japan, and naturally thermophilic heat resistant spore forming bacteria such as fiat sour bacteria have occurred. Sugar esters, that are known by their properties as emulsifier and antimierobial, may be used to inhibit growth or to reduce the heat resistanee of thermophilie baeteria. The present study was undertaken to elucidate how the sucrose palnútate P-1570 (Ryoto Sugar Ester - Mitsubishi Kagaku Foods Co.) acts against Bacillus stearothermophilus spores that were isolated from a soluble coffee sample. Suspension of B. stearothermophilus spores originally isolated from soluble coffee was prepared aeeording to method deseribed by Ptlug (1990). The sporulation was carried out in tubes with Nutrient Broth (Difeo) added 1.5% Nutrient Agar (Difeo) plus 5 ppm MnSO4. Several sucrose palmitate (P-1570) concentrations were evaluated (10 - 6000 mg/l) to determine the Minimum Inhibitory Concentration (MIC) for B. stearothermophilus vegetative growth in coffee extract with 6° Brix and pH 5.5 (EC medium) that was prepared in similar conditions of coffee extract are used to produce coffee earned drinks. Diluted samples were plated (pour-plate) on TSA (Tryptie Soy Agar Medium -Difeo) and they were ineubated for 48-72 hours at 55°C. It was observed that 200 mg/l of sucrose palmitate was enough to inhibit the development of '10 POT. 4' activated spores / mI. To determine if sucrose palmitate acts on germination or on outgrowth of B. stearothermophilus spores, these were inoculated in Nutrient Broth (pH 6.9) with and without sucrose palmitate, activated for 20 minutes and incubated for 12 hours at 55°C. Every two hours a sample was taken from the germinating medium and the optical density was measured in a BECKMAN DU 640 spectrophotometer at 590nm Under these conditions, 2.3%, 3.7% and 2.8% of germination were observed for samples with sucrose palmitate at 100, 200 and 300 mg/l respectively, while it was registered 3.3% of germination for sample without sugar ester. No outgrowth was observed with 100, 200 and 300 mg/l of sucrose palmitate indicated by no further increase in optical density in relation to control sample (no sugar ester addition). These results confirmed that effect of sugar esters is mainly related to inhibition of outgrowth. ... Note: The complete abstract is available with the full electronic digital thesis or dissertations.
Mestrado
Mestre em Ciência de Alimentos

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16

Poole, Elizabeth Jennifer. "Evaluation and localization of helper bacteria in ectomycorrhiza formation." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322938.

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Gençkal, Hande Tarı Canan. "Studies On Alkaline Protease Production From Bacillus Sp./." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/biyoteknoloji/T000505.pdf.

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Atkinson, Deborah Jane. "Stress response and inorganic poly-phosphate in the Bacillus group bacteria." Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538113.

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This thesis concentrates on the Bacillus cereus group of organisms and interactions that they may encounter in their natural environment. Inorganic polyphosphate has been identified as an important factor of stress and survival in B. cereus. One of the aims of this project was to create knock out mutants of certain enzymes involved in polyphosphate metabolism in B. anthracis, the etiological agent of anthrax. Unfortunately, even though B. anthracis is very closely related to B. cereus and despite the application of published methods it was not possible to create these B. anthracis knockout mutants. In order to address the importance of inorganic polyphosphate in B. anthracis, a real time RT‐PCR assay was developed to monitor the mRNA levels of these enzymes when the bacterium is faced with harsh nutrient environments Real time RT‐PCR analysis showed that mRNA levels of the metabolizing enzymes were upregulated in low nutrient conditions but that the profiles of gene expression were varied when grown in a chemically defined media. In addition to abiotic stresses such as low nutrients, B. anthracis is also likely to face biotic stress such as predation by amoeba in the soil. Investigations were performed into the outcome of the interaction of B. cereus group bacteria with a model amoeba, Acanthamoeba polyphaga. Amoebae are bacterial predators but can also be utilised as hosts by bacterial symbionts and pathogens, such as Legionella pneumophila. It was theorised that amoebae may provide a host environment similar to that of the professional macrophages, which B. anthracis encounters in mammalian infection. These investigations confirmed that the B. cereus group bacteria demonstrate a range of interactions with amoeba cells, from surface attachment through to intracellular persistence. These studies went on to show that B. cereus, B. thuringiensis and B. anthracis can all be engulfed by amoebae when challenged in their vegetative form and that spores were able to survive, and apparently germinate. Finally these studies have identified a new developmental stage of the B. cereus group bacteria. When grown in static conditions, especially in the presence of amoeba, the bacterial cells cease to septate and large (often motile) continuous hyphae like filaments form. These filaments can be seen to “weave” together to form large “rope” like macrofibre structures which can even become visible by eye. Previously this macrofibre growth has also been seen in B. subtilis, suggesting it may be common to the whole genus. In the light of these findings we speculate that this group of pathogens have evolved complex behaviours to interact with soil amoeba in order to facilitate survival in harsh environmental conditions.

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Sarasanandarajah, Sivananthan. "Multiwavelength fluorescence studies of Bacillus bacterial spores." Thesis, University of Canterbury. Physics and Astronomy, 2007. http://hdl.handle.net/10092/3544.

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Fluorescence techniques are being considered for the detection and identification of bacterial spores. This thesis sets out to empirically characterize the detailed autofluorescence spectroscopic properties of spores and their target molecules. The multiwavelength fluorescence studies from a unique endogenous biomarker, dipicolinic acid (DPA) and its calcium salt (CaDPA) in bacterial spores are found to be useful for fluorescence characterization of spores. A systematic determination of the fluorescence profile of the major chemical components of Bacillus spores and the effect of UV irradiation on them has been performed in dry samples, wet paste and in aqueous solution. The thesis applies reliable tools for accurately describing complex nature of spectral profile from bacterial spores, and for interpreting and identifying their spectral properties. We show that multiwavelength fluorescence technique combined with Principal Component Analysis (PCA) clearly indicates identifiable grouping among dry and wet Bacillus spore species. Differences are also observed between dried, wet and redried spores, indicating the stark effect of hydration on fluorescence fingerprints. The study revealed that changes in fluorescence of spores due to hydration/drying were reversible and supports a recent model of a dynamic and dormant spore structure. The spectra were analysed with PCA, revealing several spectroscopically characteristic features enabling spore species separation. The identified spectral features could be attributed to specific spore chemical components by comparing the spore sample signals with spectra obtained from the target molecules. PCA indicated underlying spectral patterns strongly related to species and the derived components were correlated with the chemical composition of the spore samples. More importantly, we examined and compared the fluorescence of normal spores with a mutant of the same strain whose spores lack DPA. We discovered that the dramatic fluorescence enhancement of Bacillus spores can be caused by UV irradiation in the spectral region of this unique biomarker without any pre treatment. Differences between spectra of spores, spore strains and other biological samples are very marked and are due to the dominance of the dipicolinate features in the spore spectra. This could lead to a cheap, more sensitive, faster and reagentless bacterial spore detector.

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Blackman, Stephen Andrew. "The role of autolysins during vegetative growth of Bacillus subtilis 168." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298885.

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Borkowski, Olivier. "Growth-rate-dependent protein production in bacteria." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05T004.

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Les théories actuelles suggèrent que l'efficacité de traduction (nombre de protéines produitespar ARN messager ; notion spécifique à chaque à gène) reste constante lorsque le taux decroissance varie. Néanmoins, une efficacité de traduction constante est incompatible avec lafaible corrélation observée, à l’échelle du génome, entre l’évolution en fonction du taux decroissance de la concentration des ARN messagers et des protéines pour lesquelles ils codent.Pour faire face à ce paradoxe, nous avons développé un modèle mathématique de la traductionbasé sur les connaissances actuelles de ce processus au niveau moléculaire. L’exploration despropriétés du modèle nous a amené à conduire des expériences de transcriptomique, de PCRquantitative et de Live Cell Array (LCA) dont l’analyse a montré que l'efficacité de traductiondiminue jusqu'à 4 fois entre faible et fort taux de croissance chez la bactérie modèle Bacillussubtilis. Notre modèle a révélé que la chute de l’efficacité de traduction repose sur une chutede la concentration des ribosomes libres. Pour étudier les conséquences de la chute desribosomes libres sur la production des protéines, nous avons rationnellement défini à partir dumodèle mathématique des constructions génétiques combinant des promoteurs, naturel ousynthétique, et différentes régions d'initiation de la traduction (TIRs) contrôlant l’expressiondu gène gfp. En utilisant ces constructions génétiques, nous avons montré que la productiondes protéines est non-linéaire en fonction de la concentration en ribosomes libres. Uneproduction non-linéaire entraine des efficacités de traduction différentielles des ARNmessagers en fonction de leurs TIRs. Ce mécanisme de régulation général des protéinesparticipe à la perte de corrélation entre la concentration des ARN messagers et des protéinescorrespondantes et nous a amené à revisiter la Physiologie Moléculaire Bactérienne
Current theories suggest that translation efficiency (i.e. number of proteins produced permRNA) remains invariant with increasing growth rate, which is inconsistent with the scanty correlation between mRNAs and cognate proteins abundances at the genome-scale level. We tackled this apparent paradox using a systems biology approach. We developed a knowledgebased, nonlinear mathematical model of translation. The in-depth analysis of the model led us to reassess experimentally, using high-throughput and genome-wide technologies, each measurable RNA entity at different growth rates. In contrast to the current knowledge, the total mRNA abundance was not constant but linearly increased with respect to the growth rate. A model-driven integration of genome-wide and molecular experimental datasets demonstrated that the drop in abundance of a constitutively expressed protein with increasing growth rate is not only due to the dilution but also to an unexpected up to 4-fold decrease of translation efficiency. Our model revealed that this drop relies on a drastic decrease in free (untranslating) ribosomes, a non-measurable entity. Using a set of 18 Bacillus subtilis strains combining 9 synthetic translation initiation regions (TIRs) and 2 constitutive promoters, we show that TIRs together with free ribosome abundance strongly contribute to a nonlinear modulation of single proteins as a function of the growth rate. The nonlinearity accounted for the loss of correlation between mRNAs and cognate proteins abundances. Altogether, our results evidenced a unique, hard-coded and global growth-rate-dependent regulation of single bacterial proteins without dedicated regulators

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Ferreira, Thiago Costa 1991. "Bacillus spp. como agentes de controle de Thielaviopsis paradoxa e Fusarium verticillioides e promotores de crescimento de cana-de-açúcar e milho /." Botucatu, 2018. http://hdl.handle.net/11449/157362.

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Orientador: Wagner Bettiol
Banca: Renate Kause Sakate
Banca: Silvia Renata Siciliano Wilcken
Banca: Barbara Eckstein
Banca: Lilian Simara Abreu Soares Costa
Resumo: Microrganismos podem ser utilizados como agentes de promoção de crescimento e biocontrole de fitopatógenos habitantes do solo em diferentes culturas agrícolas. Dentre estes microrganismos, existem relatos que isolados de bactérias do gênero Bacillus podem ser promissores para as duas atividades, podendo, portanto, serem efetivos para a promoção de crescimento e o biocontrole de Thielaviopsis paradoxa e Fusarium verticillioides, importantes patógenos nas culturas da cana-de-açúcar e milho, respectivamente. O objetivo deste trabalho foi selecionar isolados de Bacillus com as características de promover o crescimento das plantas e controlar T. paradoxa e F. verticillioides nas culturas da cana-de-açúcar e milho, respectivamente. Assim, foram realizados estudos in vitro com 162 isolados de Bacillus sp. quanto à assimilação de nitrogênio, solubilização de fosfato e produção de ácido indolacético, ácido cianídrico e sideróforos e também quanto à inibição do crescimento micelial e germinação de esporos de T. paradoxa e no controle da podridão abacaxi e na promoção de crescimento em cana-de-açúcar. Também foram estudados os efeitos de 12 isolados de Bacillus, selecionados de acordo com os melhores resultados da fase descrita anteriormente, bem como resultados obtidos em teste no laboratório e consulta a literatura especializada, para a promoção de crescimento e o biocontrole de F. verticiollioides em milho comum e pipoca, in vitro e in vivo. De acordo com os resultados obtidos foram ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Microorganisms can be used as plant growth promoter and biocontrol agents of soilborn plant pathogens, in several crops. Among these microorganisms, there are reports that isolates from the Bacillus genus can be promising for both these activities and may therefore be effective for the growth promotion and control of Thielaviopsis paradoxa and Fusarium verticillioides, important pathogens in sugarcane and corn crops, respectively. In this study it was selected Bacillus isolates for improving plant growth and controlling T. paradoxa and F. verticillioides. In vitro studies were carried out with 162 Bacillus isolates regarding to the assimilation of nitrogen, phosphate solubilization and production of indolacetic acid, hydrocyanic acid and siderophores, as well as the inhibition of mycelial growth and spores germination of T. paradoxa, control of pineapple rot and growth promotion in sugarcane. Also, the effects of 12 Bacillus isolates, selected according to the previously described phase and literature information, were studied for growth promotion and for the control of F. verticiollioides in corn and popcorn, in vitro and in vivo. According to the results, two isolates, B. velezensis AP-03 and Bacillus sp. AP-210, as growth promoter and biocontrol agents of T. paradoxa and F. verticillioides for sugarcane and corn crops, respectively. Bacillus spp. isolates can be used as plant growth promotion and biocontrol agent in sugarcane and corn in the presence of these soilborn plant ...
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Sirtori, Lisana Reginini. "Purificação e caracterização de uma bacteriocina produzida por Bacillus sp. P45." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/8625.

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Uma bacteriocina produzida por um microrganismo isolado do intestino do peixe Jaraqui, da bacia Amazônica, foi caracterizada. A bactéria foi identificada como pertencente ao gênero Bacillus por testes citomorfológicos, bioquímicos e fisiológicos. A análise filogenética feita através da seqüência do rDNA 16S revelou que a bactéria é geneticamente próxima de bactérias como B. subtilis e B. amyloliquefaciens. A bacteriocina foi produzida no início da fase exponencial de crescimento e a sua concentração atingiu o nível máximo no início da fase estacionária, caracterizando-se como metabólito primário. O sobrenadante inibiu Staphylococcus aureus, Salmonella Gallinarium, Listeria monocytogenes, Erwinia caratorvora entre outras espécies patogênicas. A atividade manteve-se constante em temperaturas de 10 a 100 ºC, por 30 minutos, iniciando um declínio a 100 ºC por 40 minutos. No teste do efeito de enzimas proteolíticas, a pronase E causou a perda do efeito antimicrobiano, indicando que se trata de uma substância de natureza protéica. A purificação foi realizada inicialmente por precipitação com sulfato de amônio, seguida de uma cromatografia de gel filtração (Sephadex G- 100). A etapa final foi a cromatografia de troca iônica (DEAE Sepharose). No final deste processo, obteve-se um fator de purificação de 42,6 com uma recuperação de 6,75%. A bacteriocina purificada manteve sua estabilidade térmica, mas perdeu a estabilidade frente a enzimas proteolíticas. O espectro de infravermelho indicou grupamentos NH e ligações peptídicas e o espectro de massas indicou um peptídeo de 1518,554 Da. A bacteriocina parcialmente purificada tem um EC50 de 400UA/mL e provocou uma diminuição de 6 logs de células de Listeria monocytogenes com 800UA/mL, provavelmente provocando lise celular.
A bacteriocin produced by a microrganism isolated from the intestine of the fish Jaraqui of the Amazonian basin was characterized. The bacterium was identified as a species of the Bacillus genus by cytomorphological, biochemical and physiological tests. The phylogenetical analysis done by 16S rDNA sequence revealed that the bacterium is genetically close to B. subtilis and B. amyloliquefaciens. The bacteriocin is produced at exponential growth phase and its concentration achieves the maximum level at stationary growth phase, suggesting that this compound is a primary metabolite. The culture supernatant was active against Staphylococcus aureus, Salmonella Gallinarium, Listeria monocytogenes, Erwinia caratorvora among other pathogenic species. The activity was constant in temperatures from 10 to 100 ºC for 30 minutes, begining to decline at 100 ºC for 40 minutos. When treated with proteolitic enzymes, pronase E caused the lost of the antimicrobian efect, proving that is a substance of proteinaceous nature. The purification was developed by ammoniun sulfate precipitation, followed by gel filtration chromatography (Sephadex G-100). The last step was an ion exchange chromatography (DEAE Sepharose). By the end of this process, we have a purification factor of 42,6 and a yield of 6,75%. The purified bacteriocin keeps its thermal stability, but looses the stability towards proteolytic enzymes. The infrared spectrum indicates NH groups and peptidic bounds and the mass spectrum indicates a peptide of 1518,554 Da. The bacteriocin partially purified has a EC50 of 400UA/mL and kills all viable cells of Listeria monocytogenes with 800UA/mL, probably by cell lysis.

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24

Mohallem, Maria de Lourdes. "Utilização da nisina na destribuição termica de Bacillus stearothermophilus em homogeneizado de cogumelos pH 6,2." [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255380.

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Orientador: Pilar R. de Massaguer
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O presente trabalho propôs estabelecer os parâmetros do processamento térmico utilizando-se a nisina como coadjuvante térmico no homogeneizado de cogumelos em salmoura 1,5% {p/v) pH 6,2 (HC). 0 meio HC simula uma conserva comercial não acidificada. O microrganismo alvo da destruição termoquímica foi o Bacillus stearothermophilus FS 1518. Seus esporos foram obtidos à partir de uma solução estoque e produzidos no meio Agar Nutriente {AN) contendo 5 ppm de sulfato de manganês {PFLUG, 1982}. Esta metodologia mostrou-se mais eficaz que aquela preconizada por KIM & NAYLOR (1966) . A ativação ótima para a germinação foi determinada e ficou estabelecida como 5 minutos à temperatura de ebulição nos meios de subcultura estudados. O meio Caldo Nutriente (CN) foi eleito para estudar o efeito da nisina na germinação e no crescimento pó-germinativo porque melhor se adequou ao método espectrofotométrico de redução de absorbância. Constatou-se que a nisina não inibe a germinação destes esporos. Sua inibição é posterior à germinação. Concentrações de nisina maior ou igual a 50 UI/ml inibiram a crescimento pós-germinativo. A Menor Concentração Inibitória (MCI} de nisina para as células de B. stearothermophilus FS 1518, em uma população de 106 UFC/ml, foi de 50 UI/ml. A metade da MCI foi adicionada no meio HC inoculado com os esporos para a determinação da sua resistência térmica. A redução da resistência térmica, empregando-se o meio AN para a subcultura, foi de 19, 36 e 44% nas temperaturas de 125°, 121º e 118ºC respectivamente. O índice de temperatura encontrado foi 11,66 e 9,15 com e sem nisina, respectivamente. O valor de esterilização requerido para causar 5 reduções decimais a partir de uma população de 7000 esporos/250g produto decresceu, aproximadamente, em 36% à temperatura de 121 ºC com a nisina. Estes dados comprovam a sua eficiência na redução da resistência térmica destes esporos, quando inoculados no mexo HC e nos fornece o valor de esterilização requerido para o processamento desta conserva nestas condições
Abstract: The present work intended to establish the microbiological parameters for process using nisin as a thermal adjuvant in a homogenate of mushrooms in brine 1.5 per cent (p/v) pH 6.2 (HM). The HM simulates a low-acid processed product. The target microorganism for the thermo-chemical destruction was Bacillus stearotherraophilus FS 1518. The spore suspension was obtained from a stock suspension and produced in Nutrient Agar (NA) supplemented with 5 ppm of Manganese Sulfate (PFLUG, 1982). This methodology showed to be more efficient than the one standardized by KIM & NAYLOE (1966). It was determined the optimum conditions of activation for germination on the subculture medium studied. It was found that the optimum activation time was 5 minutes at boiling temperature. Nutrient Broth was chosen as the culture medium to study the effect of nisin on the germination and post-germinative growth, because it showed to be the most adequate to the spectrophotometry method of absorbance reduction. It was observed that nisin does not inhibit germination of such spores. Its inhibiting action occurs after the germination phase. Nisin Minimum Inhibitory Concentration (MIC) for B. stearothermophilus FS 1518 in apopulation of 106 CFU/ml was 50 UI/ml. Half of this MIC was added to the HM medium previously innoculated with the spores to determine its thermo-chemical resistance. The thermo-chemical resistance reduction using HA medium for subculturing was 19, 36 and 44 per cent for temperatures of 125, 121 and 118°C, respectively. The Z-value found was 11.66 and 9.15"C with and without nisin, respectively. The sterilization value required (F) to cause 5 decimal reduction on the initial population of 7000 spores per 250 g of product decreased approximately 36 per cent at 121ºC with nisin. These data prove the efficiency of nisin in reducing the thermal resistance of such spores when inoculated in HM medium, and it also provides the F-value for processing the product in the studied conditions.
Mestrado
Mestre em Ciência de Alimentos

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25

Kushida, Marta Mitsui. "Caracterização parcial e propriedades de biosurfactantes bacterianos." [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254738.

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Orientador: Lucia Regina Durrant
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: o interesse pelos biosurfactantes tem aumentado neste final de século, principalmente por suas características superiores aos agentes emulsificantes químicos conVenCIOnaIS, como baixa toxicidade, biodegradabilidade, especificidade e síntese a partir de material renovável e de baixo custo, encontrando larga faixa de aplicações, principalmente em biorremediação, já que sabemos como são graves os problemas como vazamento de óleo que ocorrem durante o transporte dos mesmos para locais de consumo, assim como o despejo de efluentes pelas indústrias. No Laborátório de Sistemática e Fisiologia Microbiana (LSFM) foram selecionadas cepas produtoras de biosurfactantes, sendo que Planococcus citreus (9), Pantoea agglomerans (BIA) e Bacillus sp (B3G) apresentaram uma atividade emulsificante potencial, produzindo biosurfactante quando crescem em óleo de oliva, querosene e óleo de soja, respectivamente. Foram analisadas as propriedades dos biosurfactantes produzidos pelas cepas bacterianas, tais como influência de temperatura, pH, concentração de sais, etc. sobre os agentes emulsificantes.
Abstract: Interest in biosurfactants increased at the end of the 20th century because of their superior qualities to conventional chemical emulsifiers, such as low toxicity, biodegradability, specificity and synthesis from low cost renewable material, finding many applications, principalty in biorremediation, where grave problems, such as oil leaks during transport to points of consumption, as well as the discharging of efluents by industry occur. At the Systematic and Microbial Physiology Laboratory (SMPL) the selected biosurfactant-producing strains Planococcus citreus (9), Pantoea agglomerans (BlA) andBacillus sp (B3G) presented potencial emulsifying activities, producing biosurfactant when grow in olive oil, kerosene and soya oil, respectively. The properties of the biosurfactants produced by the bacterial strains where analyzed, together with the influence of temperature, pH, salt concentration, etc, on the emulsifying agents.
Mestrado
Mestre em Ciência de Alimentos

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26

Cobos, Trigueros Nazaret. "Factores de riesgo de adquisición de Pseudomonas aeruginosa y comparación de dos estrategias de uso de antibióticos (rotación frente a mezcla) en pacientes críticos: Impacto en la adquisición de microorganismos resistentes y desenlaces clínicos." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/397735.

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OBJETIVOS: Comparar en una unidad de cuidados intensivos (UCI) una estrategia de rotación de antibióticos antipseudomónicos en ciclos de 6 semanas con una estrategia de mezcla de los mismos antibióticos administrados a cada paciente consecutivo respecto a la adquisición de microorganismos resistentes o potencialmente resistentes (MRPR), al desarrollo de infección por cualquier microorganismo o por MRPR, a la duración de la estancia en la unidad y a la mortalidad. Como objetivo secundario se analizaron los factores de riesgo asociados con la adquisición de P. aeruginosa y sus fenotipos de resistencia. MÉTODOS: Estudio prospectivo comparativo de dos estrategias de utilización de antibióticos en una UCI médica durante 35 meses. En los periodos de mezclase administró a cada paciente consecutivo una clase distinta de antibióticos (meropenem ceftazidima/piperacilina-tazobactam, y fluorquinolonas). Estos periodos se alternaron con periodos de rotación en los que, a intervalos de 6 semanas, se administró cada una de las clases de antibióticos de forma preferente. Se realizó un cribado sistemático para la detección de MRPR dentro de las 48 h del ingreso y tres veces por semana posteriormente, así como el registro de todas las variables clínicas que pudieran influir en cada desenlace. Los MRPR objeto de estudio fueron: Staphylococcus aureus resistente a meticilina, enterococos resistentes a vancomicina, enterobacterias resistentes a cefalosporinas de tercera generación, Pseudomonas aeruginosa, Burkholderia cepacia, Stenotrophomonas maltophilia, Pseudomonas spp y Acinetobacter baumannii. RESULTADOS: Un total de 969 pacientes fueron ingresados en la unidad, de los cuales, 409 (42%) se incluyeron en tres periodos de mezcla y 560 (58%) en tres periodos de rotación. El uso global de antipseudomónicos no fue significativamente diferente en ambos grupos (37,5/100 pacientes-día vs. 38,1/100 pacientes-día). Hubo un ligero aumento de adquisición de MRPR durante mezcla, pero perdió significación cuando se excluyeron los casos debidos a un brote exógeno de Burkholderia cepacia (19,3% vs. 15,4%, p=0.1). La adquisición de P. aeruginosa resistente a los antibióticos intervenidos o multirresistente (MDR) fue similar en ambos periodos. No hubo diferencias en cuanto a la proporción de pacientes que adquirió cualquier infección (16,6% vs. 14,5%, p=0,4), cualquier infección por MRPR (5,9% vs. 5,2%, p=0,6), duración de la estancia o mortalidad (13,9 vs. 14,3%, p=0,9). De los 850 pacientes ingresados durante ≥3 días, 68 (8%) eran portadores de P. aeruginosa al ingreso y entre los restantes 782, 104 (13%) adquirió al menos una cepa durante la estancia en la UCI. El análisis multivariado seleccionó el shock al ingreso, la intubación, la nutrición enteral, la nutrición parenteral, la traqueostomía y la presión de colonización >0,43 como factores asociados independientemente con la adquisición de P. aeruginosa mientras que la exposición a fluoroquinolonas durante >3 días fue protectora. La exposición previa a meropenem se asoció independientemente con la resistencia a carbapenems mientras que la exposición previa a amikacina se asoció a resistencia a piperacilina-tazobactam, fluorquinolonas y MDR. CONCLUSIONES: 1. En UCIs, una estrategia de rotación de antibióticos antipseudo-mónicos en intervalos de 6 semanas es similar a una estrategia de mezcla en términos de adquisición de MRPR, desarrollo de infección, duración de la estancia y mortalidad; 2. Intervalos de uso predominante de los antibióticos antipseudomónicos previamente descritos en periodos de 6 semanas no se asocian a aumentos significativos en la prevalencia de resistencia a los mismos ni a MDR en P. aeruginosa; 3. En UCIs con una elevada prevalencia de uso de antibióticos, la presión de colonización y la exposición a ciertos procedimientos son más importantes que la exposición antibiótica como determinantes de la adquisición de P. aeruginosa. 4. Meropenem es el antibiótico que se asocia con un mayor riesgo de adquisición de P. aeruginosa resistente a sí mismo.
Objective: To compare the effect of two strategies of antibiotic use (mixing vs. cycling) on the acquisition of resistant microorganisms, infections and other clinical outcomes and to investigate risk factors for the acquisition of Pseudomonas aeruginosa and its resistance phenotypes. Methods: Prospective cohort study in a medical intensive care unit during 35- months in which a mixing-cycling policy of antipseudomonal beta-lactams (meropenem, ceftazidime/piperacillin-tazobactam) and fluoroquinolones was operative. Nasopharyngeal and rectal swabs and respiratory secretions were obtained within 48h of admission and thrice weekly thereafter. Target microorganisms included methicillin-resistant S. aureus, vancomycin-resistant enterococci, third-generation cephalosporin-resistant Enterobacteriaceae and non-fermenters. Results: A total of 409 (42%) patients were included in mixing and 560 (58%) in cycling. Overall use of antipseudomonals was not significantly between periods. There was a barely higher acquisition rate of microorganisms during mixing, but this difference lost its significance when the cases due to an exogenous Burkholderia cepacia outbreak were excluded (19.3% vs. 15. %, p=0.1). Acquisition of Pseudomonas aeruginosa resistant to the intervention antibiotics or with multiple-drug resistance was similar. There were no significant differences between mixing and cycling in the proportion of patients acquiring any infection (16.6% vs. 14.5%, p=0.4), any infection due to target microorganisms (5.9% vs. 5.2%, p=0.6), length of stay or mortality (13.9 vs. 14.3%, p=0.9). Out of 850 patients admitted for ≥3 d, 105 (12%) acquired P. aeruginosa. Multivariate analysis selected primary bacteremia on admission, emergency surgery, intubation, enteral nutrition, parenteral nutrition, tracheostomy and colonization pressure >0.43 as independently associated with the acquisition of P. aeruginosa while exposure to fluoroquinolones for >3 days was protective. Prior exposure to carbapenems was independently associated with carbapenem resistance while prior amikacin predicted piperacillin-tazobactam, fluroroquinolone and multiple-drug resistance. Conclusions: A cycling strategy of antibiotic use with a 6-week cycle duration is similar to mixing in terms of acquisition of resistant microorganisms, infections, length of stay and mortality. In critical care settings with a high rate of antibiotic use, colonization pressure and non-antibiotic exposures may be the crucial factors for P. aeruginosa acquisition while fluoroquinolones may actually decrease it.

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27

Lee, Wan-Jing. "Isolation and characterisation of phages infecting gram positive food bacteria." Thesis, University of Canterbury. School of Biological Sciences, 2008. http://hdl.handle.net/10092/3429.

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Bacteriophage (phage), virus of bacteria, has been proposed as a mean to inactivate bacteria that are pathogens of humans. Applied prophylatically to food, phage might decrease the numbers of potential pathogens we ingest. Much active research on using the phages of bacteria to control Gram negative foodborne pathogens are described in the literatures, but comparatively little research describes the phages of Gram positive bacteria and their use as biocontrol agents on food. In this work, previous undescribed phages, able to infect Bacillus cereus and Listeria monocytogenes, were isolated from soil and ruminants faecal material, respectively. As the first step in assessing their potential as biocontrol agents, the isolated phages were purified, concentrated and characterised (albeit to different degrees). The Bacillus phages had a narrow host range while the Listeria phages had a broad host range. Listeria phages also infected L. monocytogenes 2000/47, a strain which recurs in New Zealand clinical cases. Both Bacillus and Listeria phages appeared to be of the Myoviridae family judging by their structure in electron micrographs. The Bacillus FWLBc1 and FWLBc2 phages were lytic phages with a latent period of 106 and 102 min at 37°C, and an average burst size of 322 and 300 phages per infected cell, respectively. Moreover, they both had genomes of approximately 134 kb. All newly isolated and characterized phages were chloroform resistant and survived storage better at 4°C than at room or freezing temperatures. Bacillus phages significantly reduced the bacterial population in mashed potatoes within 24 h at room temperature, when applied at a phage to host ratio of 1000. Listeria phages rapidly inactivated the host population to a low optical density. The findings of this thesis will add to the current knowledge of phages in the context of various environmental conditions for different bacteria and will demonstrate the potential of phages as food safety biocontrol agents.

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Carissimi, Mariana. "Estudo da atividade antifúngica de Bacillus E164 contra Bipolaris sorokiniana." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/8791.

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O trigo é o principal cereal componente dos produtos amiláceos atualmente consumido pela população. Além das limitações econômicas e políticas, a produção brasileira de trigo encontra obstáculos como a incidência de doenças, muitas delas causadas por fungos. O fitopatógeno Bipolaris sorokiniana é o agente etiológico da helmintosporiose, cujo controle é baseado principalmente em antifúngicos sintéticos. O fungo não é o principal causador de patologias em trigo, mas é importante do ponto de vista fitossanitário nas plantações, pois se mantém no solo por longo período de tempo podendo atacar as plantações em climas úmidos e quentes. O presente estudo teve objetivos avaliar a maior atividade antifúngica de três isolados de Bacillus sp. contra 34 isolados B. sorokiniana, selecionar uma linhagem de Bacillus sp., elucidar sua atividade inibitória in vivo e avaliar as melhores condições de cultivo, propriedades físicoquímicas do cultivo filtrado obtido e a atividade antifúngica in vitro do mesmo. A bactéria com a melhor ação antagonista foi analisada quanto à produção das enzimas caseinase e lipase, produção e atividade do filtrado de cultivo em diferentes meios e após tratamento térmico e variação de pH. Também foi realizado um teste in vivo do antagonista conta o isolado 98031 do fungo. Os três isolados de Bacillus foram capazes de inibir in vitro os isolados de B. sorokiniana, mas destacaram-se os isolados E164 e C98017. Quando testado in vivo, o isolado Bacillus E164 causou efeitos sobre a morfologia da planta, como redução significativa no comprimento das raízes. No entanto, não foi possível observar um nível elevado de proteção visto que mesmo as plantas infectadas não apresentaram os sintomas da doença. A produção do filtrado foi baseada em caldo triptona de soja, uma vez que a inibição foi similar ao meio com palha de milho e maior que o meio com extrato de malte. O filtrado antifúngico apresentou resistência à fervura por até 90 minutos, mas a atividade foi significativamente diminuída nesse tratamento quando comparada aos tratamentos de 50 a 80ºC e temperatura ambiente. A refrigeração e o congelamento não causaram diminuição na atividade do filtrado. A influência do grau de ionização foi percebida nos pHs 5, 6, 8 e 10. O isolado de Bacillus E164 apresentou atividade proteolítica e lipolítica em meios específicos. O controle exercido pelo isolado Bacillus E164 sobre B. sorokininana foi relevante nos testes in vitro. Porém, a influência e a importância da ação do(s) metabólito(s) produzido(s) por esse microrganismo devem ser mais estudados para uma possível aplicabilidade in vivo.
Wheat is the main cereal component of starch products consumed by the population. Brazilian wheat production has many limitations such as government policies, economic problems, and apart from there is a large loss in production due to diseases caused by fungi. Bipolaris sorokiniana is a phytopathogen that causes helminthosporiosis in cereal crops, whose control is mainly rely on synthetical antifungal agents. It has phytossanitary importance, since it can live for a long period in the soil, and attack crops on wet and warm weather conditions. The objectives of this work were to evaluate the antifungal activity of three Bacillus sp. Strains against 34 B. sorokiniana isolates, to select the best inhibitor of them, to elucidate its action in vivo and evaluate the best cultive conditions, physic and chemical properties of the filtrated obtained and in vitro antifungal capacity. The best bacterial strain was chosen and analyzed for the proteolytic and lipolytic activities, productions and activity of the cultive filtrated after growing on different culture media and after thermal treatment or pH variation. In vivo test was made on wheat infected by 98031 isolate. All bacterial isolates were active against B. sorokiniana but E164 and C98017T were better than OR13. On in vivo test the isolate E164 caused morphological effects on the plant as significant root length reduction. Increase of plants protection was not observed, as even infected ones did not presented disease symptoms. Filtrated production was based in tryptic casein soy broth as the inhibition degree was similar to the corn straw culture and greater than malt extract broth culture. The antifungal filtrated resisted until 90 minutes at 100ºC, but significant decrease of activity was observed in this treatment when compared to 50ºC to 80ºC and environment temperature. Refrigeration and freezing did not cause loss on filtrated activity. Ionization degree influence was observed in pH 5, 6, 8 and 10. Bacillus E164 showed proteolytic and lipolytic activities in specific media. Control exerted by Bacillus E164 over B. sorokiniana isolates was relevant in vitro, nevertheless the influence and importance of the metabolites produced must be elucidated for the application in vivo.

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Marquardt, Marcos Motta. "Estudos de atividade proteolítica de Bacillus cereus em biorreator." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/7412.

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O presente trabalho teve como principal objetivo avaliar a produção de enzimas proteolíticas por Bacillus cereus. As fermentações foram conduzidas em Biorreator Biodesign, com aeração de 1vvm, temperatura de 37°C e agitação de 400 r.p.m. como parâmetros fixos. Dois meios diferentes foram utilizados, Meio Referência (MR) e Meio de Proteína de Soja PS60® (MPS1), em experimentos realizados com 24 horas. Para avaliação da produção de complexos enzimáticos, retirou-se amostras a intervalos de 3 horas para análise de valores de pH, densidade ótica e massa seca. A atividade proteolítica, concentração de proteína solúvel e açúcares redutores, contagem de células viáveis totais e esporos também foram investigadas. Os resultados demonstraram que ambos os meios propiciaram condições para o ótimo desenvolvimento do B. cereus. Os resultados também indicam que, embora os dois meios tenham apresentado um crescimento celular semelhante, o meio composto por proteína de soja propiciou a obtenção de um extrato bruto com atividade proteolítica mais elevada. Nas condições de fermentação empregadas, o meio MPS1 apresentou em 15 horas uma atividade enzimática de 18,7UmL-1.h-1.enquanto que o meio MR apresentou uma atividade proteolítica de 11,8 UmL-1.h-1.

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30

Ng, Ho-yin Ricky, and 吳浩然. "Identification of anaerobic, non-sporulating, Gram-positive bacilli from blood cultures by 16S rRNA gene sequencing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44670424.

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Tagliari, Cristiane Vanessa. "Produção de xilanases alcalinas por Bacillus pumilus e sua aplicação no branqueamento de polpas kraft." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266937.

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Orientador: Telma Teixeira Franco
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Para reduzir os problemas ambientais, a indústria de papel e celulose vem buscando alternativas para seus processos de branqueamento através da tecnologia enzimática. Desta forma, xilanases tem sido empregadas durante o processo de pré-branqueamento de polpas Kraft, com intuito de diminuir a carga de cloro utilizada nas etapas subseqüentes. Xilanases ativas a altas temperaturas (acima de 45 °C) e pH alcalino possuem elevado potencial de aplicação em branqueamento de polpas de papel, já que podem ser introduzidas livremente nos diferentes estágios do processo sem a necessidade de drásticas etapas de resfriamento ou ajustes de pH. Bactérias são aptas a produzir enzimas que atuam nestas condições, tornando atrativo o estudo da produção de xilanase por Bacillus pumilus. Para viabilizar a aplicação de xilanases em larga escala é necessário que esta seja obtida com alta produtividade e baixo custo. Neste trabalho foram investigadas as condições de produção de xilanases alcalinas por B. pumilus em fermentação submersa. O meio de cultivo foi estudado por planejamento estatístico, objetivando maximizar a produção de xilanases em frascos agitados. Após determinar as melhores condições de cultivo, um biorreator com volume útil de 2L foi utilizado para produzir a quantidade necessária de enzima para aplicação nos testes de branqueamento. A maior produção da enzima em frascos agitados (129 U/mL) foi verificada no ponto central do segundo planejamento experimental em 20 horas de fermentação, o qual apresentava 3% xilana, 0,6% peptona, 0,15% sulfato de amónio e pH 9,5. Foi verificado que a produtividade aumentou (170 U/mL em 10 horas) quando a enzima foi produzida em biorreator de 2 L, evidenciando o potencial do B. pumilus para a produção de xilanases alcalinas e termofílicas. Quanto a aplicação da enzima no pré-branqueamento de polpas Kraft, foi verificado uma deslignificação de 26% quando a polpa foi tratada com xilanases na dosagem de 50U/g polpa seca, resultado superior aos encontrados na literatura.
Abstract: Environmental concerns, have put a restriction on the usage of chlorine during bleaching process in the paper and pulp industry. Therefore, xylanase pretreatment has been used to lower bleaching chemical consumption. Enzymes which are active under alkaline conditions and higher temperatures, have great potential for industrial application, such as the bleaching process, without any need for cooling or changes in pH and with the advantage in lowering the release of polluting organic chlorine compounds. Bactérias are able to produce enzymes that act in these conditions, than being attractive xylanase production by Bacillus pumilus. For industrial large scale aplication, the enzyme should be obtained with high productivity and low cost. This work investigated the optimal conditions of alkaline xylanases produced by B. pumilus in submerged fermentation. The culture media was studied by statistical factorial design, aiming to increase the xilanases production. The best conditions were applied in 2L bioreactor to produce the enzyme necessary for application in bleaching process. The highest xylanase production in culture flasks (129 U/mL) was obtained at central point of the second factorial design in 20 hours of fermentation, which contained 3% xylan, 0.6% peptone, 0.15% ammonium sulfate and pH 9.5. It was observed that the productivity increased (170 U/mL in 10 hours) when the enzyme was produced in 2 L biorreator, evidencing the potential of the B. pumilus for the production of thermophilic and alkaline xylanases. The effect of xylanase treatment (50U/g pulp) on hardwood pulp was significant. A decrease of 2.5 units in kappa number was achieved (26% of delignification) suggesting that the xylanase from B. pumilus has a great potential in kraft pulp bleaching.
Mestrado
Mestre em Engenharia Química

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32

Altan, Asena Yenidünya Ali Fazıl. "Isolation And Molecular Characterization of Extracellular Lipase And Pectinase Producing Bacteria From Olive Oil Mills/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/biyoteknoloji/T000497.pdf.

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33

Kendall, Lonnie Vern. "The host immune response to the cilia-associated respiratory (CAR) bacillus and immunopathogensis [i.e. immunopathogenesis] of disease /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9974646.

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Kendall, Lonnie Vern. "The host immune response to the cilia-associated respiratory (CAR) bacillus and immunopathogensis [sic] of disease." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9974646.

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GARVEY, KEVIN JAMES. "DNA SEQUENCE ANALYSIS OF BACILLUS PHAGE PHI29 RIGHT EARLY REGION AND LATE GENES 14, 15 AND 16 (LYSOZYME)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183839.

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The sequence of the rightmost 4,626 bp of the Bacillus phage φ29 genome is presented and analyzed. Nine large open reading frames (ORF's) have been found. Three of these ORF's are correlated with the late genes 14, 15 and 16. The remaining six ORF's are in the right early region. One of these early ORF's has been identified as gene 17 (g17), the only early gene to have been genetically mapped in this region. The remaining ORF's (16.5, 16.6, 16.7, 16.8 and 16.9) were previously unknown. The biological efficacies of some of these putative early ORF's were demonstrated using an in vitro E. coli transcription-translation system. The primary amino acid sequences, molecular weights, translational initiation sequences and genetic organization of these nine genes are presented and discussed. Gene product 15 (gp15) was found to have strong homology with Salmonella phage P22 gp19, a lysozyme. gp15 also has a lesser but possibly significant homology with T4 gene product e (gpe), also a lysozyme. Using a clone containing φ29 g15 it was shown that gp15 can complement T4 gene e (ge) mutant infections, leading to the conclusion that φ29 g15 encodes a lysozyme. Three transcriptional initiation sites (P(E)3, P(EC)3 and B2) were previously mapped in this region. The sequences of the putative P(EC)3 and B2 promoter sites are presented and shown to have homology with the Bacillus σ⁵⁵ concensus sequence. Sequences having homology to a minor Bacillus sigma factor recognition site, σ³², are also presented and discussed. The region between the last late gene (g16) and the last early gene (ORF-16.5) consists of only 30 bp. Analysis of potential secondary structures of transcripts across this region suggests that the same sequences may be involved in the termination of both late and early transcription.

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Yssel, Anna Elizabeth Johanna. "The spatial evolution of the chemotaxis proteins of the Bacillus subtilis group." Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1004087.

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The aim of this work was to study spatial evolution of the chemotaxis proteins of a group of plant-associated soil-dwelling bacteria vernacularly referred to as the B. subtilis group. This was achieved by creating homology models for the chemotaxis proteins if a suitable template was available, and by analysing the selective forces (positive, purifying or neutral) acting upon the chemotaxis proteins. Chemotaxis is the phenomenon in which bacteria direct their movement towards more favourable conditions, and is critical for processes such as obtaining nutrients, escaping toxic compounds, host colonization and bio-film formation. Members of the B. subtilis group exhibit different preferences for certain host plants, and it is therefore feasible that their chemotactic machinery are fine-tuned to respond optimally to the conditions of the various niches that the strains inhabit. Homology models were inferred for the plant growth promoting B. amyloliquefaciens FZB42 proteins CheB, CheC, CheD, CheR, CheW and CheY. The interactions between: CheC-CheD, the P1 and P2 domains of CheA with CheY and CheB, and the P4 and P5 domains of CheA with CheW were also modelled. The hydrophobic interactions contributing to intra- and inter-protein contacts were analysed. The models of the interactions between CheB and the various domains of CheA are of particular interest, because to date no structures have been solved that show an interaction between a histidine kinase (such as CheA) and a multidomain response regulator (such as CheB). Furthermore, evidence that phospho-CheB may inhibit the formation of phospho-CheY by competitively binding to the P2 domain of CheA is also presented. Proteins were analysed to determine if individual amino acid sites are under positive, neutral or purifying selection. The Methyl Accepting Chemotaxis Proteins (MCPs), CheA and CheV were also analyzed, but due to a lack of suitable templates, no homology models were constructed. Site-specific positive and purifying selection were estimated by comparing the ratios of non-synonymous to synonymous substitutions at each site in the sequences for the chemotaxis proteins as well as for the receptors McpA, McpB, and McpC. Homology models were coloured according to intensity of selective forces. It was found that the chemotaxis proteins of member of the B. subtilis group are under strong evolutionary constraints, hence it is unlikely that positive selection in these proteins are responsible for the differences in habitat preference that these organism exhibit.

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Krueger, Cristhiane Leite. "Seleção de linhagens de Bacillus produtoras de polihidroxialcanoatos a partir de resíduo do processamento de mandioca." Florianópolis, SC, 2009. http://repositorio.ufsc.br/xmlui/handle/123456789/92705.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Alimentos.
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Frente aos problemas ocasionados pelo uso dos plásticos de origem petroquímica, surgiu a necessidade de se buscarem alternativas para substituição deste material. Apresentam-se como solução os plásticos biodegradáveis, ou bioplásticos, que são polímeros com as propriedades desejáveis dos plásticos convencionais e rapidamente biodegradados quando descartados no ambiente. Dentre eles, estão os polihidroxialcanoatos (PHAs), poliésteres compostos por monômeros de ácidos 3-hidroxialcanóicos, os quais são acumulados intracelularmente por bactérias, como reserva de carbono e/ou energia, sob limitação de um nutriente essencial ao seu crescimento, e o polímero mais estudado atualmente é o P(3HB) - poli(3-hidroxibutirato). Entretanto, o custo de produção de PHAs é um dos responsáveis pela limitação de sua produção e comercialização. A utilização de substratos de baixo custo se torna um fator importante para a redução do custo de produção, além da busca e obtenção de linhagens eficientes na conversão do substrato em polímero. O objetivo deste trabalho foi selecionar, numa coleção de microrganismos do Laboratório de Microbiologia Aplicada - UNIVALI/SC, uma linhagem bacteriana capaz de produzir PHA a partir de resíduo do processamento de mandioca. Inicialmente, 72 isolados de Bacillus, Paenibacillus e Geobacillus de 21 espécies diferentes foram cultivados em meio com limitação de fósforo e 20g/L de resíduo industrial oriundo do processamento de mandioca, rico em amido e açúcares redutores. Foram avaliados o crescimento dos microrganismos em meio com substrato amiláceo (técnica de MTT), sua capacidade de secretar enzimas no meio (avaliação de degradação de amido) e a produção de PHA (cultivo com corante vermelho do Nilo e observação em microscópio de epifluorescência). Finalmente foram selecionados 4 isolados: LAMA073, LAMA095, LAMA262 e LAMA265, classificados por métodos moleculares como Bacillus megaterium, os quais foram capazes de produzir P(3HB) a partir do resíduo amiláceo. O resíduo industrial utilizado mostrou-se, portanto, um substrato carbônico aplicável à produção de compostos de maior valor agregado, como P(3HB). Os isolados LAMA073, LAMA095, LAMA262 e LAMA265 acumularam 13,04% (p/p), 23,88% (p/p), 5,92% (p/p), e 25,00% (p/p) de P(3HB), respectivamente, a partir de 20% de resíduo hidrolisado adicionado ao meio. Quando adicionado resíduo hidrolisado na concentração de 40%, os isolados LAMA073 e LAMA095 apresentaram aumento na produção de P(3HB), para 30,45% (p/p) e 29,78% (p/p), respectivamente. A espectroscopia na região do infravermelho com transformada de Fourier (FTIR), das amostras de PHAs produzidos, mostraram bandas características da presença de P(3HB), confirmando a produção deste polímero pelos microrganismos. Portanto, os isolados identificados e caracterizados apresentam potencial para a produção de P(3HB) em substrato de baixo custo, sendo um próximo passo avaliá-los em uma escala superior de produção, bem como em outros resíduos amiláceos. There are many problems caused by use of petrochemical plastics, then it is necessary to find alternatives to replace this material. A solution for this problem is the use of biodegradable plastic, or bioplastics, which are polymers with desirable properties of conventional plastics, and they are rapidly biodegraded in the environment when they are discarded. Among the biodegradable plastics, there are the polyhydroxyalkanoates (PHAs), polyester containing hydroxyalkanoic acid monomers. They are accumulated intracellularly by bacteria as carbon or energy reserves, when there is a limitation of an essencial nutrient, and P(3HB) - poly(3-hydroxybutyrate) is the most studied polymer nowadays. However, the use of PHA is limited due to its high cost production. The use of low cost by-products becomes the main factor for the reduction of production cost, besides that it is also necessary to obtain strains for efficient substrate conversion into polymer. The objective of this work was to select a bacterial strain capable of producing PHA from cassava by-products as carbon source. First screening was conduced with 72 strains from culture collection of the Applied Microbiology Laboratory (UNIVALI/SC/Brazil), covering three generas (Bacillus, Geobacillus and Paenibacillus) and 21 different species, which were cultivated in Minimal Medium (MM) with limited phosphate and 20g/L of cassava by-product. It was evaluated microorganisms growth (measuring respiration by MTT assay) in medium with starchy substrate, their ability to secrete enzymes (starch degradation) and PHA production (Nile red dying assay and observation in epifluorescence microscope). Finally 4 isolates were selected: LAMA073, LAMA095, LAMA262 and LAMA265, classified by molecular methods (16S rRNA sequencing) as Bacillus megaterium, which were capable of producing P(3HB) from cassava processing by-products as a sole carbon source. Strains LAMA073, LAMA095, LAMA262 and LAMA265 were able to produce 13,04% of P(3HB) (w/w), 23,88% (w/w), 5,92% (w/w) and 25,00% (w/w) respectively, when cultivated in MM supplemented with 20% of hydrolized cassava by-product. However, when 40% of hydrolized cassava by-product was used, higher P(3HB) percentage, 30,45% and 29,78% (w/w), was observed for LAMA073 and LAMA095, respectively. Fourier transform infrared spectroscopy (FTIR) showed characteristic bands of P(3HB) presence, confirming polymer production by microorganisms. Therefore, the identified and characterized strains have potential to produce P(3HB) in low-cost substrate, and a next study would be evaluate them on a higher scale of production, as well as production in others starchy waste.

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Dragana, Tamindžija. "Isolation and characterization of Cr(VI) tolerant soil bacteria." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2019. https://www.cris.uns.ac.rs/record.jsf?recordId=110336&source=NDLTD&language=en.

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In this study, tolerance of soil bacteria to hexavalent chromium (Cr(VI)) was investigated. First, influence of high chromium levels of anthropogenic and geogenic origin on the soil cultivable bacterial community was examined. Next, a number of bacterial strains with high Cr(VI) tolerance were isolated from diverse environmental samples such as soil, sediment, water and waste material. Strains were identified and tested for the level of Cr(VI) tolerance and the ability toreduce toxic Cr(VI) to more innocuous Cr(III). Selected Bacillus cereus group strains were further characterized - their morphological and biochemical characteristics, 16S rRNA and pycA gene sequences, biofilm formation potential and resistance to other heavy metals were determined. Also, more detailed study of their tolerance level and Cr(VI) reduction was conducted. Strain with the highest resistance together with the control chromate sensitive strain were analyzed by STEM EDS for their cellular and endospore Cr content under different conditions. Results indicate Cr(VI) tolerant bacteria are present both in low and high Cr environments. Majority of isolates belonged to the B. cereus group indicating its overall high tolerance to Cr(VI). Certain strains exhibited high tolerance and reduction ability, indicating their possibleusefulness in practical bioremediation application. STEM EDS analysis of Cr(VI)-sensitive B. subtilis PY79 strain and Cr(VI)-resistant B. cereus group strain NCr1a revealed significant differences in their response to Cr(VI) and in their Cr cellular and endospore content.
U ovom radu ispitana je tolerantnost zemljišnih bakterija na šestovalentni hrom (Cr(VI)). Prvo, ispitan je uticaj visokog nivoa hroma antropogenog i geogenog porekla na kultivabilnu bakterijsku zajednicu zemljišta. Dalje, izolovani su bakterijski sojevi sa visokom tolerancijom na Cr(VI) iz različitih sredinskih uzoraka kao što su zemljište, sediment, voda i otpadni materijal. Sojevi su identifikovani i određen je nivo njihove Cr(VI) tolerancije i sposobnost redukcije toksičnog Cr(VI) u manje toksični Cr(III). Odabrani sojevi Bacillus cereus grupe su dalje karakterisani – određene su njihove morfološke i biohemijske karakteristike, 16S rDNK i pycA sekvence, potencijal formiranja biofilma i otpornost na druge teške metale. Takođe, sprovedeno je detaljnije ispitivanje njihove tolerancije i redukcije Cr(VI). Soj sa najvišom otpornošću je uporedo sa kontrolnim osetljivim sojem analiziran pomoću STEM EDS na sadržaj hroma u ćelijama I endosporama u različitim uslovima. Rezultati ukazuju da su bakterije tolerantne na Cr(VI) prisutne i u sredinama sa niskim i sa visokim koncentracijama hroma. Većina izolata pripadala je B. cereus grupi što ukazuje na njenu uopšteno visoku otpornost na Cr(VI). Pojedini sojevi su pokazali visoku otpornost i sposobnost redukcije Cr(VI), što ukazuje na mogućnost njihove praktične primene u bioremedijaciji. STEM EDS analiza osetljivog B. subtilis PY79 soja i Cr(VI)- rezistentnog soja B. cereus grupe NCr1a otkrila je značajne razlike u njihovom odgovoru na Cr(VI) i sadržaju Cr u njihovim ćelijama i endosporama.

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39

Avery, Kathryn. "Mechanistic studies on a cytochrome P450 enzyme from the bacteria Bacillus megaterium." Thesis, University of Leicester, 1999. http://hdl.handle.net/2381/30028.

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A cytochrome P450 enzyme from the bacteria Bacillus megaterium (P450BM-3) has been shown to have unique structural and functional properties. P450BM-3 strikingly contrasts with other P450 enzymes as it is a soluble, catalytically self-sufficient, single polypeptide protein, with both electron transfer and substrate oxidation domains contained in one protein. For these results, possibly, P450BM-3 is the most catalytically active P450 enzyme known to date. P450BM-3 catalyses the hydroxylation of long to mid-chain fatty acids, and fatty amides and alcohols to corresponding monohydroxy derivatives on the -1, -2 and -3 positions. The potential application of P450BM-3 in synthetic chemistry has been assessed in studies using a range of synthesised long chain fatty acid derivatives. Chapter 2 describes a study of 13(R)-hydroxymyristic acid, 12(R)-hydroxymyristic acid and 12(S)-hydroxymyristic acid as substrates, which has uncovered a degree of diastereoselectivity in the formation of 12,13-dihydroxymyristic acid products. In chapter 3 a range of mid-chain phenoxy compounds, with varying lengths of terminal alkyl chains, has been used to show regioselectivity in the P450BM-3 oxidation of these types of substrates to hydroxy and keto derivatives. In chapter 4, 11-phenylsulphanylundecanoic acid has been shown to be oxidised by P450BM-3 to a corresponding sulphoxide with a high degree of regioselectivity but non-stereoselectively. The synthesis of substrates and the characterisation of products from corresponding P450BM-3 metabolisms are fully discussed.

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40

Benini, Stefano. "Structure and function relationships of urease and cytochrome c-553 from Bacillus pasteurii." Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325599.

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41

Olivera, Florencia Cladera. "Produção, caracterização, purificação parcial e aplicação de um peptídeo antimicrobiano produzido por Bacillus licheniformis P40." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2004. http://hdl.handle.net/10183/4839.

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Uma bactéria identificada como Bacillus licheniformis P40 isolada de intestino de peixe (Leporinus sp.) da bacia amazônica foi estudada quanto à sua capacidade de produzir antimicrobianos. O sobrenadante da cultura obtido em caldo de cérebro e coração (BHI) foi caracterizado, sendo ativo contra importantes bactérias patogênicas e deteriorantes como L. monocytogenes, B. cereus, E. carotovora e isolados clínicos de Streptococcus. Este foi parcialmente purificado através de precipitação com sulfato de amônio e cromatografia de gel filtração e de troca iônica. Foram assim isoladas duas substâncias com atividade antimicrobiana, sendo uma delas de natureza protéica. Esta foi estável a altas temperaturas (100o C), numa ampla faixa de pH e mostrou propriedades de biosurfactante. O sobrenadante parcialmente purificado foi utilizado para o combate a um importante fitopatógeno: Erwinia carotovora. Uma dose de 6400 UA/mL foi bactericida para uma concentração de 107 UFC/mL em 20 minutos in vitro. A substância foi capaz de evitar a formação da podridão mole em batatas (in vivo). Foi estudada a produção da atividade antimicrobiana em resíduos e sub-produtos da indústria de alimentos, sendo escolhido o soro de queijo para otimizar a produção através de um experimento fatorial 23 variando as condições de temperatura, pH e concentração de soro de queijo em pó. As melhores condições foram para temperaturas entre 26 e 37o C e pH entre 6,5 e 7,5 para uma concentração de soro de 7%, sendo que aumentos na concentração levaram a aumentos na produção.

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42

Mattapally, Peter Vijay. "Characterizing Bacillus amyloliquefaciens UCMB5113 on a Plant Model Arabidopsis thaliana." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-38378.

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Organic farming is gaining importance and acceptance worldwide due to its beneficial effects in agriculture and standing against losses caused by chemical fertilizers, pesticides and fungicides. Plant growth promoting bacteria (PGPB) plays an important role in organic farming by fixing atmospheric nitrogen, chelate iron, solubilizing phosphorous, producing and modulating phytohormones, providing antibiotics against pathogens. Understanding interaction mechanisms between PGPB and plant will be helpful in developing new formulations to form a strong symbiotic relationship between plant and bacteria. Bacillus amyloliquefaciens UCMB5113 is a red pigmented, rod shaped Gram positive bacteria which has been isolated from fields of the Ukraine. In the present study UCMB5113 and its interactions with the plant has been characterized. There was a significant promotion of plant root growth and protection against biotic stress with the application of 10 μl of 1x107/ml CFU UCMB5113 culture in Arabidopsis. The UCMB5113 can significantly withstand plant antimicrobial activity to stimulate plant root growth, but needs root hair defective RHD proteins to stimulate root hair elongation. UCMB5113 has significantly inhibited primary root elongation and developed number of lateral roots and root hairs in ethylene over expressed mutant, which suggests that it may be affecting ethylene signaling pathway in plants. UCMB5113 has a distinct red pigmentation which is a 38.5kDa water soluble protein with maximum absorbance at 422nm. These features are similar to the Orange Carotenoid Protein (OCP) of Synechocystis PCC 6803. This red pigmented protein has no significant effect on plant root growth promotion. Further biochemical and molecular studies are required to characterize and confirm the mechanisms of interaction.

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Shane, William T. "Persistence of Spore Forming Bacteria on Drinking Water Biofilm and Evaluation of Decontamination Methods." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1205164893.

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Dullaghan, Edith Mary. "Analysis of gene regulation by mycobacterium tuberculosis LexA." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311969.

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Bim, Monica Andrea. "Extração em sistema de duas fases aquosas de xilanase alcalina produzida por Bacillus pumilus e aplicação no branquamento da polpa kraft." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266329.

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Orientador: Telma Teixeira Franco
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: A xilana, a qual é hidrolisada pela xilanase, é um abundante biopolímero encontrado no tecido de vegetais como constituinte principal da parede celular. Muitas das xilanases comercialmente disponíveis são produzidas por fungos com atividade ótima a pHs ácidos ou neutros e a temperaturas abaixo de 45°C. Existem várias aplicações para a xilanase, mas o seu maior potencial de uso é na industria de papel e celulose nos processos de branqueamento da polpa. Deste modo, xilanases ativas em condições alcalinas são potencialmente úteis nos processos de branqueamento de polpa de papel sem necessidade de mudanças no pH do processo e com a vantagem de diminuir a quantidade de componentes organoclorados nos efluentes das indústrias de papel. As duas motivações principais deste trabalho foram: primeiro, utilizar sistema de duas fases aquosas (SDFA) para extrair e purificar a xilanase do caldo de fermentação, produzido por Bacillus pumilus, pois o uso de SDFA pode ser uma alternativa mais econômica e de fácil operação, para purificação de bioprodutos, visto que as etapas de extração e purificação representam até 80% do custo destes bioprodutos. Segundo, aplicar a xilanase no branqueamento da polpa kraft de eucalipto visando a redução de organoclorados no efluente das indústrias de papel e celulose ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: Xylan, a group of heteropolysaccharides, is an abundant biopolymer found in plant tissues as major component of cell wall, which is hydrolysed by xylanase. Several of the xylanases commercially available produced by fungi are active at neutral or acidic pH and their optimum temperature is below 45°C. Various applications for xylanases in bioconversion and food industries have been suggested and one of the major potential applications of xylanases involves the pulp and paper industry. This way, enzymes which are active at alkaline conditions have great potential in bleaching process without any need for changes in pH and with the advantage in lowering the release of polluting organic chlorine compounds. The two main motivations of this work was: first, to extract and to purify the enzyme from the crude fermentation broth, produced by Bacillus pumilus, using aqueous two phase systems (ATPS). Second, application ofxylanase ftom crude fermentation broth at hardwood kraft pulp bleaching. The enzyme from crude fermentation broth was extracted by partitioning in ATPS composed of phosphate and polyethyleneglycol (pEG). The effect of tie-line length, PEG molecular weight and NaCl and phosphate concentrations upon the purification factors and yields of xylanase were investigated by statistical design. The best system studied was that one containing 22% PEG6000, 10%¿K IND. 2¿¿HP¿O IND. 4¿ and 12% NaCl with a purification factor of 40 and 97% yield of enzyme activity ...Note: The complete abstract is available with the full electronic digital thesis or dissertations
Mestrado
Mestre em Engenharia Química

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Pacheco, Cristiana de Paula. "Validação do processo de esterilização para polpa de tomate em unidade UHT." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255391.

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Orientador : Pilar Rodriguez de Massaguer
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Abstract: The abstract is available with the full electronic digital document
Mestrado
Mestre em Ciência de Alimentos

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Taffarello, Luciana Afonso Bittar. "Produção, purificação parcial, caracterização e aplicações de alfa-amilase termoestavel produzida por bacterias." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256715.

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Orientador: Glaucia Maria Pastore
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Mestrado

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48

Thomaides, Helena B. "Identification and characterisation of genes involved in cell division and sporulation in Bacillus subtilis." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325926.

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Havel, Timothy Joseph. "Ultraviolet disinfection of synthetic metalworking fluid contaminated with Bacillus subtilis /." Oklahoma City : [s.n.], 2002. http://library.ouhsc.edu/epub/theses/Havel-Timothy-Joseph.pdf.

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50

Al-Zenki, Sameer F. "Purification, characterization, production and application of biopreservatives from Bacillus species." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36867.

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A total of twenty-eight Bacillus spp. isolated from value-added surimi nuggets and their raw ingredients, were tested against each other and selected reference strains of Bacillus and Clostridium for their production of inhibitory substances using the deferred antagonism assay plating method. The isolated Bacillus strains showed inhibitory activity against all Bacillus strains, with the exception of the producer strain, as well as being effective against various strains of C. botulinum (type A, B and E). Subsequent studies showed that the inhibitory activity was detected in the culture supernatant in the late stationary phase of growth prior to sporulation. The inhibitory activity of two Bacillus strains (FN2A and FN33) were selected for further study. The inhibitory substances produced by these two strains were proteinaceous in nature, heat stable (100°C for 15min) and unaffected by organic solvents. A comprehensive study was conducted on the structural characterization of the inhibitor produced by B. subtilis FN2A using FPLC, FTIR, MS and MS/MS. Structural analysis of the inhibitor produced by B. subtilis FN2A showed that it was similar in structure to Surfactin.
Preliminary studies have shown that the Surfactin-like-compound from B. subtilis FN2A was produced in significant amounts during growth in bread with maximum production occurring in the late stationary phase (72h), at 30--35°C and at pH 6.5--7.0. Optimization studies on the production of the Surfactin-like-compound by B. subtilis FN2A in bread using a response surface methodology approach showed that temperature (33--36°C); autoclaving time (30 min); inoculum level (4%), alkali pre-treatment (0.16%), water activity (0.995) and pH 6.66 enhanced the production of the Surfactin-like-compound in bread. The compound produced under these optimal conditions also maintained its activity when subjected to various processing treatments (autoclaving, freezing and freeze drying).
Initial studies showed that low levels (1% w/w) of the Surfactin-like-compound inhibited the growth of B. cereus and proteolytic and non-proteolytic strains of C. botulinum in a model agar system. However, it had no effect on non-proteolytic strains of C. botulinum when bread, or methanol extracts of bread (1--20%), were added to formulated value-added sterile trout nuggets, with all nuggets being toxic after 28 days at 12°C. Furthermore, inoculation of B. subtilis FN2A directly into nuggets also failed to inhibit growth of non-proteolytic strains of C. botulinum. Omitting certain ingredients in the formulation failed to enhance the anti-botulinal effect of the bread or methanol extracts of the Surfactin-like-compound in the value-added nuggets. However, reducing the pH of the nuggets to ~5.5 enhanced the anti-botulinal effect of the Surfactin-like-compound. Further research is required to improve the dispersibility of the Surfactin-like-compound to inhibit the growth of C. botulinum in food systems.

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Dissertations / Theses on the topic 'Bacillus (bacteria)'

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