Academic literature on the topic 'Bacillus; Enterobacter'

Twenty-one isolates of the bacterium Bacillus subtilis and one of Enterobacter aerogenes were tested on agar for antagonism to Alternaria alternata, Armillariella mellea, Botrytis allii, Botrytis cinerea, Colletotrichum lindemuthianum, Monilinia fructicola, Penicillium expansum, Phytophthora cactorum, Pythium ultimum, Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium cepivorum, Verticillium dahliae, and Venturia inequalis, causal organisms of many plant diseases. Enterobacter aerogenes was antagonisic to all of the pathogenic fungi tested except Verticillium dahliae and Armillariella mellea. Similarly, Bacillus subtilis was antagonistic to all of the pathogenic fungi tested except Pythium ultimum. When Enterobacter aerogenes and Bacillus subtilis were tested in vivo on cherry fruit for control of postharvest brown rot and alternaria rot, Enterobacter aerogenes was ineffective. Eleven isolates of Bacillus subtilis provided effective alternaria rot control and 15 isolates provided brown rot control which ranked with the best fungicide control.

Biosurfactants are surface-active biomolecules produced by microorganisms that have different applications in solving many environmental problems. This study was carried out to screen biosurfactant-producing bacteria isolated from hydrocarbon-contaminated soil of Kano Metropolis, Kano State- Nigeria. Soil samples were collected and processed. Biosurfactant-producing bacteria were enumerated, isolated and characterized using cultural, morphological and biochemical characteristics. Blood haemolysis, oil drop collapse and oil displacement tests were employed for the screening of the bacterial isolates for the potential to produce biosurfactant. The viable aerobic heterotrophic bacterial count of the samples ranges from 1.0 to 8.4×106 cfu/g. Eight bacterial genera were biochemically identified as Pseudomonas aeruginosa, Enterobacter cloacae, Pantoea agglomerans, Pseudomonas sp., Bacillus subtilis, Enterobacter alvei, Bacillus sp. and Klebsiella sp. Bacillus subtilis had the highest frequency of occurrence of 5(27%) while Bacillus sp. and Enterobacter alvei have the least occurrences of 1(6%) each. The eight identified bacterial isolates were all positive for the haemolysis test, drop collapse and oil displacement test.

Four bacterial isolates from Ranu Pani and Ranu Grati in east java had been revealed to be potentials to produce IAA (PIS isolate), phosphate solubilizer (GPS isolate), cellulose hydrolysis (PSS isolate) and, amylum hydrolysis (PAS), two dominant bacterial isolates from Rani Pani (PØD isolate) and Ranu Grati (GØD isolate) which were co-cultured with microalgae promoted microalgae growth, yet its taxonomical position has not been clearly known. The aim of this study was to identify those bacterial isolates using 16S rRNA barcode. This research conducted by gDNA isolation, the 16S rRNA sequence was amplified using 27F and 1492R primers. Reconstructed phylogenetic trees and genetic distance analysis showed that the isolate PIS and PSS identified as Bacillus cereus Group closely related to Bacillus paramycoides. PAS isolate identified as Bacillus subtilis Group closely related to Bacillus amyloliquefaciens, GPS isolate identified as novel species in genus Enterobacter, and two dominant isolates (PØD and GØD) identified as Enterobacter cloacae complex closely related to Enterobacter cloacae. The genomic approach and additional phenotypes-examination are required to clarify its taxonomical position.

Background: The presence of spent hydrocarbon in soil is a serious problem to the environment hence study on bioremediation of soil polluted with auto-mechanic oil in Abuja Metropolis was carried out. Methods: A total of twenty (20) soil samples were collected, bacteria were isolated from the contaminated soil and identified using standard microbiological methods. The spent hydrocarbon utilization was determined using Atomic Adsorption UV Spectrometer. Results: The total viable count of the bacteria was 1.07 x 106 from Apo Mechanic village, 1.10 x 106 from Utako Mechanic workshops, 0.40 x 106 from Gwarinpa Mechanic workshops and 2.04 x 106 from Area one Mechanic workshops. The percentage occurrence of bacteria from Apo Mechanic village was Enterobacter species 40.0%, Pseudomonas synxantha 60.0%, Bacillus zanthoxyli 40.0% and Proteus vulgaris 20.0%. Utako Mechanic workshops were Enterobacter kobei 20.0%, Pseudomonas synxantha 40.0%, Bacillus zanthoxyli 20.0% and Proteus vulgaris 40.0%. Gwarinpa Mechanic workshops were Pseudomonas synxantha 20.0% and Bacillus zanthoxyli 20.0%. Area one Mechanic workshops were Enterobacter kobei 40.0% and Pseudomonas synxantha 40.0%. The effect of days on utilization of spent hydrocarbon showed that Pseudomonas synxantha had highest utilized of spent hydrocarbon 19.55mg/ml after 21 days. The effect of pH on utilization of spent hydrocarbon show that at pH 7.5, Enterobacter kobei, Bacillus zanthoxyli and Proteus vulgaris species had the highest utilization of spent hydrocarbon ranging from 5 9.33mg/ml-12.70mg/ml. Effect of temperature on utilization of spent hydrocarbon showed that at 28OC Enterobacter kobei, Pseudomonas synxantha, Bacillus zanthxyli and Proteus vulgaris had the highest utilization of spent hydrocarbon ranging from 5.51mg/ml- 11.11mg/ml. the bacteria isolated from the contaminated soil have the ability to utilized the hydrocarbon if the soil is amended with some mineral element as shown in this study. Conclusion: In conclusion bacteria isolates effectively bioremediated the automechanic oil polluted soil with a reduction of hydrocarbon pollutants.

Mercury (Hg) is one of the most toxic metals and is not essential for any organism. In this study, the potential of maize plants in association with bacteria to treat oxisol contaminated with Hg (II) was evaluated. The experiment was conducted in a controlled environment, and pots with 2 kg of oxisol were contaminated with HgCl2 solution at a dose of 36 mg kg-1 of Hg in a 7x4 factorial scheme: control (soil without Hg(II) and microorganisms), T2= (soil with Hg(II) and without microorganisms), and T3= soil with Hg(II) + Enterobacter cloacae, T4= Hg(II) + Bacillus subtilis, T5= Hg(II) + Enterobacter sp., T6= Hg(II) + Staphylococcus epidermidis, and T7= Hg(II) + Bacillus sp. Total Hg quantification was performed by atomic absorption spectrophotometry. At the end of the experiment, the soil pH was significantly lower (0.3 to 0.4 pH unit) in the T2 (no inoculation), Enterobacter cloacae, Enterobacter sp. and Bacillus sp. treatments. Neither contamination of soil with Hg nor plant associations with bacteria led to differences in the root dry mass of maize plants. Maize plants associated with Staphylococcus epidermidis and Bacillus sp. bacteria had lower shoot biomass (71 and 50%) compared to the treatment 2. The best remedial effect was observed with the association of maize plants with Bacillus sp., which recovered 19.67% of Hg(II) in the soil when compared to control and treatment 2 and treatment with B. subtilis. The recommendation is the use of B. subtilis to decrease the toxicity caused by Hg(II).

Abstract For clean and sustainable agriculture based on natural, non-chemical products, a field experiment was conducted during the agricultural season 2021-2022 on the cowpea plant in Salah Al-Din Governorate to evaluate the effect of six biofertilizers prepared from local bacterial isolates, which included: Bradyrhizobium manausense, Bradyrhizobium vignae, Rhizobium sp., Enterobacter cloaca, Enterobacter ludwigii, Bacillus cereus, in the growth and yield of cowpea in gypsiferous soil. The results showed that all inoculated treatments were significantly superior to the control treatment in all growth and yield traits of cowpea plant, it also appeared that a significant superiority of Brad. manausense biofertilizer followed by Brady. vignae in all plant traits: root nodules number, weight of root nodules, plant height, dry weight of plant, early yield of pods, concentration of nitrogen and phosphorus in plant as it recorded 53 nodule plant−1, 2.01 g nodule−1, 58.42 cm, 63.83g plant−1, 3658 g plant−1, 4.12 N %, 0.49 P % respectively, compared to the control treatment which recorded 0 nodule plant−1, 0 g nodule−1, 27.1 cm, 15.32g plant−1 950 g plant−1, 1.34 N %, 0.13 P % respectively, and the results showed that the treatments with Rhizobium sp., Enterobacter cloaca, Enterobacter ludwigii, Bacillus cereus biofertizers did not record any formation of root nodules, also the results indicated that the treatment inoculated with the inoculum prepared from Enterobacter cloaca bacteria was superior to Rhizobium sp, Bacillus cereus, Enterobacter ludwigii treatments in plant height, shoot dry weight and pod yield of cowpea plant.

Bacteria are present in stingless bee nest products. However, detailed information on their characteristics is scarce. Thus, this study aims to investigate the characteristics of bacterial species isolated from Malaysian stingless bee, Heterotrigona itama, nest products. Honey, bee bread and propolis were collected aseptically from four geographical localities of Malaysia. Total plate count (TPC), bacterial identification, phenotypic profile and enzymatic and antibacterial activities were studied. The results indicated that the number of TPC varies from one location to another. A total of 41 different bacterial isolates from the phyla Firmicutes, Proteobacteria and Actinobacteria were identified. Bacillus species were the major bacteria found. Therein, Bacillus cereus was the most frequently isolated species followed by Bacillus aryabhattai, Bacillus oleronius, Bacillus stratosphericus, Bacillus altitudinis, Bacillus amyloliquefaciens, Bacillus nealsonii, Bacillus toyonensis, Bacillus subtilis, Bacillus safensis, Bacillus pseudomycoides, Enterobacter asburiae, Enterobacter cloacae, Pantoea dispersa and Streptomyces kunmingensis. Phenotypic profile of 15 bacterial isolates using GEN III MicroPlate™ system revealed most of the isolates as capable to utilise carbohydrates as well as amino acids and carboxylic acids and derivatives. Proteolytic, lipolytic and cellulolytic activities as determined by enzymatic assays were detected in Bacillus stratosphericus PD6, Bacillus amyloliquefaciens PD9, Bacillus subtilis BD3 and Bacillus safensis BD9. Bacillus amyloliquefaciens PD9 showed broad-spectrum of antimicrobial activity against Gram-positive and Gram-negative bacteria in vitro. The multienzymes and antimicrobial activities exhibited by the bacterial isolates from H. itama nest products could provide potential sources of enzymes and antimicrobial compounds for biotechnological applications.

More than 900 culturable, heterotrophic aerobic isolates were obtained from the sediments of a forested, pristine stream and analyzed using three classical microbiological tests: API 20E, amplified ribosomal DNA restriction analysis (ARDRA), and fatty acid analysis. Gram-negative bacteria comprised most of the heterotrophic aerobic isolates (66.7%), similar to other oligotrophic environments. The isolates were assigned to the genus level as Pseudomonas, Flavobacterium, Micrococcus, Bacillus, Chromobacterium, Acinetobacter, Alcaligenes, Aeromonas, Methylobacterium, Enterobacter, Corynebacterium, and Sporolactobacillus. Genotypic analysis by ARDRA facilitated the comparison among strains within Pseudomonas, Bacillus, and Enterobacter groups. Temperature and predation may influence the survival of bacteria during seasons, as shown previously by others. Our results showed that the number of heterotrophic aerobic bacteria, especially Enterobacter, Alcaligenes, and Aeromonas, and Gram-positive bacteria, decreased in winter compared to summer conditions.Key words: stream, heterotrophic aerobic bacteria, ARDRA.

There are two methods to identify the bacterial characteristic, namely biochemical analysis and the 16S ribosomal ribonucleic acid gene (16S rRNA) sequencing analysis. The research aimed to identify the cultured bacterial from ex-tin mining lakes by biochemistry analysis and molecular approach. Nine bacterial were cultured and isolated in nutrient agar and then biochemically characterized by microbact™ 12A and 24E (Oxoid) identification kits. In addition, molecular analysis by 16S rRNA gene was sequenced primer 1492R and primer 27F. Based on biochemistry analysis, these bacterial were identified as belonging to species of Bacillus amyloliquefaciens; Enterobacter gergoviae; Enterobacter aerogenes; Enterobacter agglomerans; and Nitrobacter spp. The sequence analysis in gene bank of NCBI indicated that these species had similarity with Klebsiella variicola strain F2R9 (Accession NR_025635.1); Enterobacter cloacae subsp. dissolvens strain LMG 2683 (Accession NR_044978.1); Serratia marcescens strain NBRC 102204 (Accession NR_114043.1); Bacillus marisflavi strain TF-11 (Accession NR_118437.1); Falsibacillus pallidus strain CW 7 (Accession NR_116287.1); Klebsiella pneumoniae strain DSM 30104 (Accession NR_117683.1); and Nitrobacter winogradskyi strain Nb-255 (Accession NR_074324.1). However, phylogenetic tree was constructed by Neighbor-Joining Test showed the cultured bacterial were not in the same clade and also with Salmonella enterica subsp. enterica strain LT2 (Accession NR_074910.1); Bacillus amyloliquefaciens strain BCRC 11601; and Escherichia coli strain NBRC 102203 (Accession NR_114042.1) as in group species and Micrococcus luteus strain NCTC 2665 (Accession NR_075062.2); Chloroflexus islandicus strain isl-2 (Accession NR_148571.2); Flavobacterium gondwanense (Accession M92278.1); and Cytophaga aurantiaca strain JM110 (Accession MN758870.1) as their out group.ABSTRAKTerdapat dua metode untuk mengidentifikasi karakteristik bakteri, yaitu analisis biokimia dan analisis sekuensing gen 16S ribosomal ribonucleic acid (16S rRNA). Karakterisasi bakteri telah dilakukan melalui analisis morfologi dan biokimia dan dikonfirmasimelalui pendekatan molekuler menggunakan sekuensing gen 16S ribosomal ribonucleic acid (16S rRNA). Penelitian ini bertujuan untuk mengidentifikasi bakteri yang dapat dikultur dari danau pascatambang timah melalui analisis biokimiawi dan pendekatan molekuler. Sembilan bakteria berhasil dikultur dan diisolasi di media nutrient agar dan kemudian secara biokimiawi dikarakterisasi menggunakan microbact™ 12A and 24E (Oxoid) identification kits. Lebih lanjut, analisis molekuler menggunakan gen 16S rRNA dilakukan sekuensing dengan primer 1492R dan primer 27F. berdasarkan analisis biokimia, bakteri-bakteri tersebut termasuk ke dalam spesies Bacillus amyloliquefaciens; Enterobacter gergoviae; Enterobacter aerogenes; Enterobacter agglomerans; dan Nitrobacter spp. Analisis blasting pada gene bank di NCBI mengindikasikan bahwa spesies-spesies tersebut memiliki kemiripan atau similaritas dengan Klebsiella variicola strain F2R9 (Accession NR_025635.1); Enterobacter cloacae subsp. dissolvens strain LMG 2683 (Accession NR_044978.1); Serratia marcescens strain NBRC 102204 (Accession NR_114043.1); Bacillus marisflavi strain TF-11 (Accession NR_118437.1); Falsibacillus pallidus strain CW 7 (Accession NR_116287.1); Klebsiella pneumoniae strain DSM 30104 (Accession NR_117683.1); dan Nitrobacter winogradskyi strain Nb-255 (Accession NR_074324.1). Namun, pohon filogenetik yang dikonstruksikan dengan Neighbor-Joining Test menunjukkan bahwa bakteri yang dikultur tersebut tidak berada pada clade dan juga dengan Salmonella enterica subsp. enterica strain LT2 (Accession NR_074910.1); Bacillus amyloliquefaciens strain BCRC 11601; dan Escherichia coli strain NBRC 102203 (Accession NR_114042.1) yang digunakan sebagai spesies in group species maupun Micrococcus luteus strain NCTC 2665 (Accession NR_075062.2); Chloroflexus islandicus strain isl-2 (Accession NR_148571.2); Flavobacterium gondwanense (Accession M92278.1); dan Cytophaga aurantiaca strain JM110 (Accession MN758870.1) sebagai out groupnya.

Neste estudo, avaliou-se o efeito da microbiolização de sementes com bactérias extremófilas facultativas (Bacillus sp. e Enterobacter sp.), isoladas, em trabalhos anteriores, a partir de condições extremas de pH e NaCl e capazes de levar ao incremento na fitomassa de eucalipto, na germinação de Eucalyptus urophylla S.T. Blake. Para avaliar a germinabilidade, foram mensurados o tempo médio, a velocidade e o coeficiente de velocidade de germinação. O delineamento experimental foi inteiramente casualizado com 11 tratamentos (cinco estirpes de Bacillus sp., cinco de Enterobacter sp. e uma testemunha sem bactéria), formados por oito repetições com 25 sementes cada. Os resultados do estudo indicaram que as estirpes UnB 1366 e UnB 1374 de Bacillus sp. reduziram, significativamente, menor tempo médio e maiores coeficientes e velocidades de germinação em relação às demais estirpes.

Orientadores: Arnaldo Yoshiteru Kuaye, Marcelo Palma Sircili<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos<br>Made available in DSpace on 2018-08-15T20:40:16Z (GMT). No. of bitstreams: 1 Esper_LucianaMariaRamires_D.pdf: 999342 bytes, checksum: 3f9fabfdcb18d73bafce5fd0ce00935e (MD5) Previous issue date: 2010<br>Resumo: A contaminação de fórmulas infantis por Enterobacter sakazakii (Cronobacter spp.) e Bacillus cereus pode ter como origem o contato do alimento com biofilmes formados em ambientes, utensílios e equipamentos empregados na sua produção ou posterior reconstituição nos locais de distribuição. A grande preocupação em relação a estas bactérias é a presença das mesmas em fórmulas infantis, produtos estes utilizados como fonte de alimentação para lactentes de forma exclusiva ou em combinação com outros alimentos. A formação de biofilmes, assim como outros mecanismos celulares como por exemplo a produção de bacteriocinas e fatores de virulência, podem ser modulados pelo processo de comunicação célula-célula ou quorum sensing - mecanismo de sinalização célula-célula mediada pelo acúmulo de uma classe ou mais de moléculas sinalizadoras produzidas pela célula e excretadas para o meio externo. Por sua vez, a quebra deste sistema, pela degradação das moléculas sinalizadoras de comunicação, denomina-se quorum quenching. Neste trabalho objetivou-se, primeiramente, a avaliação da dinâmica de formação de biofilmes mono e multi-espécies de E. sakazakii (Cronobacter spp.) e B. cereus em superfície de aço inoxidável utilizando-se como meios de cultivos fórmula Infantil (FI) e caldo Luria Bertani (LB) e a eficácia de soluções de ácido peracético e de hipoclorito de sódio na inativação desses biofilmes. Outro objetivo principal foi pesquisar a ocorrência dos sistemas quorum sensing e quorum quenching em E. sakazakii (Cronobacter spp.) e B. cereus e a possível influência das moléculas sinalizadoras na sensibilidade destas bactérias aos antimicrobianos. A formação de biofilmes ocorreu de forma mais intensa ao utilizar-se a fórmula infantil, quando comparado com o meio de cultivo LB, fato este relevante por ser a fórmula infantil o mais conhecido e importante veículo de transmissão de E. sakazakii (Cronobacter spp.). Tanto em cultivo mono-espécie quanto em cultivo misto, o nível de contagem de E. sakazakii (Cronobacter spp.) superou o de B. cereus e para ambos o maior desenvolvimento ocorreu em cultivos mono-espécie. Em todos os biofilmes de E. sakazakii (Cronobacter spp.) e B. cereus isoladamente e em cultura mista, produzidos em caldo LB e independente do tempo de formação, as contagens foram reduzidas a níveis inferiores a 1 logUFC/cm2 quando em contato com soluções de ácido peracético ([500mg/L]) e hipoclorito de sódio ([100mg/L]) por 15 minutos. No entanto, para os biofilmes produzidos em fórmula infantil ocorreram algumas situações, em que as contagens de microrganismos após o contato com as soluções de sanitizantes, foram superiores a 1 logUFC/cm2, evidenciando assim a ineficácia do procedimento de sanitização para alguns biofilmes formados a 5 dias ou mais e a necessidade da higienização das superfícies ser realizada o mais próximo do término do processamento ou reconstituição destes alimentos. Evidenciou-se a existência dos sistemas quorum sensing e quorum quenching, através dos testes de atividades biológicas das culturas, extratos e suas frações. Os testes com os biossensores revelaram-se positivos para a produção de homoserinas lactonas em cepa de E. sakazakii (Cronobacter spp.) e negativos para a espécie B. cereus. Em cultivo misto de E. sakazakii (Cronobacter spp.) e B. cereus observou-se a redução e/ou a não detecção das homoserinas lactonas fato este possivelmente associado ao fenômeno quorum quenching. A possível presença de moléculas sinalizadoras AI- 2 e AI-3 foi evidenciada, sendo confirmada a presença de moléculas sinalizadoras AI-1. A caracterização do AI-1 realizada por cromatografia gasosa acoplada à espectrometria de massa (CG-EM) revelou a capacidade da cepa de E. sakazakii (Cronobacter spp.) em produzir três compostos, N-heptanoil-HSL, N-dodecanoil- HSL e N-tetradecanoil-HSL, substâncias estas ainda não reportadas na literatura para o microrganismo em estudo. Os autoindutores sintéticos C7-HSL, C12-HSL e C14-HSL adicionados a cultura de E. sakazakii (Cronobacter spp.) e B. cereus não exerceram efeito sobre a sensibilidade aos antimicrobianos, sugerindo que estas moléculas não estariam envolvidas em mecanismos de resistência a estes antimicrobianos. Em resumo este trabalho representa um importante passo no estudo da formação de biofilmes e dos sistemas quorum sensing e quenching para as bactérias em questão, cujos conhecimentos são de grande interesse na segurança dos alimentos<br>Abstract: The contamination of infant formulas by Enterobacter sakazakii (Cronobacter spp.) and Bacillus cereus can occur due to contact with biofilms formed in the environment and on equipment used in their production and reconstitution. There is concern about these bacteria due to their presence in foods used as a source of nutrition for infants. Biofilm formation as a wide spectrum of important processes is reported to be regulated by quorum sensing, including, for example, antibiotic production and virulence. Cell-to-cell communication or bacterial quorum sensing is a signaling mechanism that refers to the ability of bacteria to respond to chemical molecules called autoinducers, in response to cell density. Degradation of the signaling molecule prevents it from accumulating in sufficient amounts, leading to disruption of the communication system, known as quorum quenching. The aim of this study was first to evaluate the formation of mono and multi-species biofilms of Enterobacter sakazakii (Cronobacter spp.) and B. cereus on stainless steel surfaces using infant formula (FI) and Luria Bertani (LB) broth as the culture media, and the efficacy of sodium hypochlorite and peracetic acid in inactivating these biofilms. The other objective was to investigate the involvement of Enterobacter sakazakii (Cronobacter spp.) and Bacillus cereus in quorum sensing and quorum quenching systems and the possible influence of the signaling molecules on the sensibility of these bacteria to antimicrobials. The formation of biofilms was greater when using the infant formula than the Luria Bertani broth, this fact being important since the infant formula is considered to be an important vehicle in the transmission of Enterobacter sakazakii (Cronobacter spp.) to infants. In both cases, the growth of the mono species was greater than in the multi species culture. In all the biofilms formed in the Luria Bertani broth, independent of the time of formation, the counts were reduced to less than 1 log CFU/cm2 when in contact with sodium hypochlorite ([100mg/L]) or peracetic acid ([500mg/L]). However for the biofilms produced in the infant formula, many situations occurred, with counts more than1 log CFU/cm2 in some situations after the contact with sanitizers highlighting the need for na efficient sanitization of the surfaces as soon as the processing or reconstitution of these foods has finished. The experiments with biosensors provided evidence of the occurrence of quorum sensing and quorum quenching systems using bioassays with the cultures and extracts of the microorganisms under examination. These bioassays were positive for the production of homoserine lactone by E. sakazakii (Cronobacter spp.) but negative for B.cereus. In the mixed culture a reduction and/or non-detection of the homoserine lactone was observed, a fact that could be associated with quorum quenching. A possible presence of the signaling molecules AI-2 and AI-3 was evident and the presence of AI-1 was confirmed. Gas chromatography-mass spectrometry (GC-MS) analyses allowed for a chemical identification of the production of N-heptanoyl-HSL, N-dodecanoyl- HSL and N-tetradecanoyl-HSLby the E. sakazakii (Cronobacter spp.), a fact not previously reported in the literature. The addition of synthetic signaling molecules (N-heptanoyl-HSL, N-dodecanoyl-HSL and N-tetradecanoyl-HSL) had no significant effect on the sensibility of the E. sakazakii (Cronobacter spp.) and B. cereus strains to antimicrobials. In summary this study represents an important step in biofilm's formation, quorum sensing and quorum quenching in these bacteria that are of great interest in food safety<br>Doutorado<br>Doutor em Tecnologia de Alimentos

Orientador: Anita Jocelyne Marsaioli<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química<br>Made available in DSpace on 2018-08-21T09:27:02Z (GMT). No. of bitstreams: 1 Araujo_FranciscaDianadaSilva_D.pdf: 5387746 bytes, checksum: ae8110c020cf470d09fb0e22f670508f (MD5) Previous issue date: 2012<br>Resumo: Aspectos distintos da ecologia química de bactéria, fungo e abelha foram investigados e abordados em três capítulos. O primeiro capítulo descreve o estudo das moléculas sinalizadoras envolvidas no processo de quorum-sensing da bactéria Enterobacter sakazakii (Cronobacter spp.), que resultou na identificação de três acil-homosserina lactonas (acil-HSLs): (S)-(-)-N-heptanoil-HSL, (S)-(-)-N-dodecanoil-HSL e (S)-(-)-N-tetradecanoil-HSL. Estes semioquímicos foram degradados por enzimas de Bacillus cereus. No segundo capítulo o estudo do fungo Epicoccum nigrum possibilitou o isolamento de meleína, 4,5-dimetil-resorcinol, flavipina e de um novo metabólito, denominado epicolactona. O monitoramento destas substâncias em três mutantes de E. nigrum apontou para a produção de 5-hidroxi-meleína, ausente no fungo selvagem, indicando que a rota biossintética de policetídeos em E. nigrum foi alterada, ativando a ação de uma mono-oxigenase responsável pela oxidação da meleína. No terceiro capítulo, foram investigados feromônios produzidos por diferentes castas da abelha social Tetragonisca angustula. Bioensaios com as rainhas indicaram que lipídios cuticulares são possíveis responsáveis pela indução da cópula nos machos. Operárias fundadoras e guardas foram diferenciadas quimicamente por compostos presentes em seus extratos cefálicos e abdominais. Extratos cefálicos de machos em diferentes ciclos de vida mostraram-se semelhantes<br>Abstract: Different aspects of bacteria, fungus and bee chemical ecology were investigated and discussed in three chapters. First chapter describes the study of signaling molecules involved in the Enterobacter sakazakii (Cronobacter spp.) quorum sensing process that resulted in the identification of three acyl-homoserine lactones (acyl-HSLs): (S)-(-)-N-heptanoyl-HSL, (S)-(-)-N-dodecanoyl-HSL and (S)-(-)-N-tetradecanoyl-HSL. These semiochemicals were modified by Bacillus cereus enzymes. Second chapter describes the study of Epicoccum nigrum (fungus) revealing the isolation of mellein, 4,5-dimethylresorcinol, flavipin and of a novel metabolite, named epicolactone. Monitoring these compounds in three E. nigrum mutants pointed to the production of 5-hydroxymellein, absent in wild fungus strain, indicating that biosynthetic route of polyketides in E. nigrum has been modified, activating a monooxygenase responsible for mellein oxidation. Third chapter describes pheromones produced by different castes of Tetragonisca angustula social bee. Bioassays with queens indicated that cuticular lipids might be responsible for copulation induction in males. Cephalic and abdominal extracts of founded and guard workers were chemically different, while cephalic extracts of males at different life cycles were similar<br>Doutorado<br>Quimica Organica<br>Doutora em Ciências

La pourriture grise causée par le champignon phytopathogène Botrytis cinerea, omniprésent et très polyphage, a clairement un impact dans de nombreuses régions en raison de la large gamme d'hôtes y compris la vigne (Vitis vinifera L.), causant de graves dommages dépassant 10 à 100 milliards de dollars dans le monde. Les fongicides chimiques, qui sont la mesure la plus importante pour assurer un rendement adéquat, restent la méthode la plus courante pour lutter contre la pourriture grise. Cependant, malgré la diversité des produits utilisés, des cas de résistance sont détectés. Aussi, la lutte chimique a révélé des effets néfastes sur l'environnement et la santé du consommateur ce qui a remis en cause son application. Pour y remedier, des méthodes de lutte alternatives en l’occurrence l'efficacité des agents de lutte biologique a été étudiée avec un grand succès. Ainsi, l’objectif de notre étude portera sur l'utilisation de bactéries bénéfiques pour lutter contre la pourriture grise de la vigne. La rhizosphère de la vigne est riche en microorganismes qui présentent de fortes aptitudes dans la lutte biologique contre les maladies des plantes. Dans la présente étude, l’isolement de microorganismes bénéfiques a été réalisé sur des plantes de vigne saines. Quarante deux bactéries ont été isolées de différents sols rizosphériques échantillonnés dans les principaux vignobles de la région de Meknès au Maroc (Latitude 33.75989, Longitude -5.43909). Le test d’antagonisme in vitro des différents isolats envers B. cinerea a révélé que parmi l’ensemble des isolats testés les souches S3, S4, S5 et S6 ont montré un résultat positif. Ces isolats inhibent la croissance du B. cinerea. Les quatres souches ont été identifiées par l’étude des caractères biochimiques et l’analyse phylogénétique des séquences du gène de l’ARNr 16S. Les résultats des analyses ont montré que les souches bactériennes retenues ont été apparentées aux espèces, du genre Bacillus, suivantes : S3 : B. velezensis ; S4 : B. velezensis ; et S5 : B. halotollerans. L’isolat S6 a été classé dans le genre Enterobacter et identifié comme étant E. cloacae. Le test d’antagonisme effectuén planta sur des vitroplants de vigne indique que les quatres rhizobactéries réduisent de façon plus ou moins significative, (59 %, 39 %, 55 %, et 17 %, respectivement), les symptômes de la maladie et réduisent les dommages de l’activité photosynthétique (PSII) dus à l’attaque de B. cinerea. Cette étude a permis de révéler que les souches du genre Bacillus et Enterobacter isolées de la rhizosphère de la vigne pourraient être utilisées comme agents de lutte biologique dans la protection de la vigne<br>The gray mold caused by Botrytis cinerea has a devastating impact on various economically important crops, including grapevine (Vitis vinifera L.), with annual economic losses exceeding10 to 100 billion dollars worldwide. Currently, pesticides remain the main method used to reduce the incidence of this phytopathogenic fungus. However, in addition to emergence of multidrug resistance, chemicals must be increasingly restricted in order to limit their impact on the environment and human health. Thus, in recent years, biological protection is gaining renewed interest. Therefore, the aim of our project is the development of new biotechnologies allowing the grapevine to better resist pathogenic pressures, through the use of beneficial microorganisms. The rhizosphere is a rich source of microorganisms with strong abilities in the biocontrol of plant diseases. In the present study, isolation of plant beneficial microorganisms was carried out on healthy plants. A total of 42 micro-organisms were isolated from different rhizospheric semi-arid soils collected in vineyards of Meknes in Morocco (Latitude 33.75989, Longitude -5.43909). The in vitro antagonism test of the various isolates towards B. cinerea evealed that among all the isolates tested the strains S3, S4, S5 and S6 showed a positive result. These isolates inhibit the growth of B. cinerea. The four strains were identified by the study of biochemical characters and phylogenetic analysis of 16S rRNA gene sequences. The results of the analyzes showed that the bacterial strains retained were related to the following species, of the Bacillus genus: S3: B. velezensis; S4: B. velezensis; and S5: B. halotollerans. Isolate S6 was classified in the genus Enterobacter and identified as E. cloacae. The antagonism test carried out in planta on vine vitroplants indicates that the four rhizobacteria reduce significantly (59%, 39%, 55%, and 17%, respectively), the symptoms of the disease and reduce damage to photosynthetic activity (PSII) due to attack by B. cinerea. This study revealed that strains of the genus Bacillus and Enterobacter isolated from the rhizosphere of the vine could be used as biological control agents in the protection of the vine

L’objectif principal de ce travail vise à améliorer la qualité sanitaire des bouillies infantiles à base de céréales fermentées de mil, consommées en Afrique comme aliments de complément à l’allaitement maternel. Ces bouillies doivent être exemptes de germes susceptibles de provoquer des toxi-infections alimentaires. L’évaluation de la qualité bactériologique des produits issus de 10 sites de la commune de Ouagadougou au Burkina Faso, nous a permis d’isoler et d’identifier 449 souches des échantillons prélevés à différentes étapes de la fabrication de la bouillie que sont : avant la fermentation de la pâte, à la fin de la fermentation, après la cuisson de la pâte fermentée et lors de la confection des granules. Des dénombrements microbiens réalisés sur les milieux Mac Conkey, Baird Parker, Mannitol-Yolk-Polymyxin et Tryptone Sulfite Cyclosérine de tous les échantillons montrent la présence en grand nombre de différents germes, signe pour certains sites d’une mauvaise hygiène des produits et des procédés. Pour les entérobactéries, l’espèce la plus rencontrée est Klebsiella pneumo. Ssp pneumonia. Pour les autres bacilles Gram négatif, c’est l’espèce Chryoseomonas luteola. Pour les staphylocoques, c’est l’espèce Staphylococcus xylosus. Pour les bacilles gram positif aptes à sporuler ce sont des souches de Bacillus cereus et de Clostridium beijerinckii /butyricum. D’un point de vue toxi-infections alimentaires, les espèces suivantes ont été isolées et identifiées : Bacillus cereus (19 souches), Enterobacter sakazakii (03), Klebsiella pneumo. Spp pneumonia (16), Escherichia coli (04) et Staphylococcus aureus (02). Globalement, on observe une diminution importante des niveaux de population après la fermentation mais les bacilles capables de sporuler se maintiennent dans les produits après cette étape importante du procédé. La cuisson entraine une diminution drastique voir la disparition de la majorité des germes sauf pour les bacilles aptes à la sporulation. L’analyse des dangers lors de la fabrication des bouillies a montré que la fermentation et la cuisson de la pâte fermentée sont deux points critiques qu’il faut maitriser. Des challenge-tests réalisés avec les souches Escherichia coli ATCC 25922, Enterobacter sakazakii CIP 103183T, Bacillus cereus ATCC 9139 de collection ou les souches Escherichia coli AMC2-1, Enterobacter sakazakii AMC8-3, Bacillus cereus BMYP7-3 isolées des ateliers ont permis l’évaluation du risque de leur développement et ce à certaines étapes des procédés de transformation. La fermentation lactique et surtout la cuisson s’avèrent efficaces pour réduire les populations d’entérobactéries testées. Pour les souches de Bacillus cereus testées, elle ne constitue pas une barrière efficace contre le maintien de leurs formes sporulées. Il en ressort que pour ces différents germes utilisés, la maîtrise du processus de fermentation lors de la décantation de la pâte, la maîtrise de la cuisson à travers le couple temps/température, les contaminations croisées liées à la qualité des ustensiles et à la propreté des productrices sont à maitriser pour l’obtention d’une bouillie « saine ». La recontamination de la bouillie cuite reste un danger. L’ajout de nisine dans les bouillies, est sans effet sur les entérobactéries testées alors que cet ajout permet de réduire efficacement les populations de bacillus cereus. Cette molécule thermostable pourrait être ajoutée en fin d’étape de fermentation et avant cuisson pour cumuler les deux effets : destruction thermique par cuisson et inhibition par la nisine<br>The aims of this work were to improve the quality of traditional millet-based fermented gruels for young children consumed in Africa as complementary foods. These gruels must be free from pathogens likely to cause food infections. The evaluation of the bacteriological quality of the products resulting from 10 production units of Ouagadougou town in Burkina Faso, allowed us to isolate and identify 449 bacteria from the samples taken at different steps during gruel manufacture: before the fermentation of the dough, at the end of the fermentation, after cooking of the fermented dough and granule production. Microbial enumerations were carried out on Mac-Conkey, Baird Parker, Mannitol-Yolk-Polymyxin and Trypton Sulfite Cycloserin mediums. All the samples showed the presence in great numbers of various pathogens, because of the bad hygiene of the products and process. For the enterobacteria, the most frequent was Klebsiella pneumo. Ssp pneumonia. For the other Gram negative bacilli, it was Chryoseomonas luteola. For the staphylococci, it was Staphylococcus xylosus. For sporulating Gram positive bacteria, we are identified Bacillus cereus and Clostridium beijerinckii/butyricum. With regard to food infections, the following species were isolated and identified: Bacillus cereus (19 species), Enterobacter sakazakii (03), Klebsiella pneumo. Spp pneumonia (16), Escherichia coli (04) and Staphylococcus aureus (02). Globally, we observed a major reduction in population levels after fermentation, but the bacilli able to sporulate were maintained in the products after this important step of the process. Cooking involved a drastic reduction in the majority of pathogens except the bacilli able to sporulate. Challenge-tests carried out with Escherichia coli ATCC 25922, Enterobacter sakazakii CIP 103183T, Bacillus cereus ATCC 9139 from a collection or Escherichia coli AMC2-1, Enterobacter sakazakii AMC8-3 and Bacillus cereus BMYP7-3 isolated from the production units, allowed the evaluation of the risk of their development and that with different steps of the process. Lactic fermentation and especially cooking were effective at reducing the populations of enterobacteria tested. For Bacillus cereus, it does not constitute an effective barrier against the maintenance of the spores. This reveals that for the various pathogens used, control of the process of fermentation during the decantation of the dough, control of cooking through time/temperature, cross contaminations related on the quality of the utensils and general cleanliness have to be controlled to obtain a “healthy” gruel. The cross contamination of the cooked gruel remains a danger. The addition of nisin in the gruel is without effect on the enterobacteria tested, whereas this addition makes it possible to reduce effectively the populations of Bacillus cereus. This heat-resistant molecule could be added at the end of the fermentation step and before cooking to combine the two effects: thermal destruction by cooking and inhibition by nisin

Os carbapenêmicos são os antimicrobianos mais amplamente utilizados no tratamento empírico de infecções graves por bacilos Gram-negativos. A pressão seletiva gerada pelo uso desses antimicrobianos ao longo das últimas três décadas contribuiu para a disseminação de enterobactérias e Gram-negativos não fermentadores produtores de carbapenemases, particularmente as do tipo KPC e NDM. Os genes que codificam essas enzimas usualmente estão localizados em plasmídeos e/ou transpósons. A hipótese atualmente mais aceita é que o gene blaNDM-1 seja uma quimera criada em Acinetobacter baumannii. A NDM-1 foi descrita em paciente proveniente da Índia e subsequentemente evidenciou-se sua ampla disseminação nesse país. A epidemiologia que tem sido observada nos casos detectados na Europa e Estados Unidos tem sido viagem à Índia, ou seja, sem casos autóctones. No Brasil, os primeiros casos foram identificados no Rio Grande do Sul, e a seguir no Rio de Janeiro e em São Paulo. Diferentemente dos casos da Europa e América do Norte, os casos do Brasil não tem relação epidemiológica com a Índia. O sequenciamento integral dos plasmídeos e cromossomos albergando o gene blaNDM permitirá entender como ocorre a disseminação desse mecanismo de resistência no Brasil. Para isso, foi avaliado o perfil de susceptibilidade dos isolados, bem como a capacidade conjugativa e clonalidade. Das vinte e oito amostras utilizadas neste trabalho, treze delas pertencem à espécie Enterobacter hormaechei, uma à espécie Citrobacter freundii, sete à espécie Escherichia coli, quatro à Klebsiella pneumoniae e três ao gênero Acinetobacter spp. Os primeiros isolados incluídos neste estudo (Escherichia coli e Enterobacter hormaechei produzindo NDM-1) foram isolados em agosto de 2013, de uma mesma amostra de swab retal de um paciente do Rio de Janeiro que nunca viajou para o exterior. O sequenciamento completo do DNA plasmidial utilizando a plataforma Illumina e a anotação de ambos os plasmídeos albergando o gene blaNDM-1 revelou que estes pertencem a grupos de incompatibilidade diferentes, IncFIIK (E. hormaechei) e IncX3 (E. coli), e abrigam um novo transpóson composto designado Tn3000. A comparação da sequência nucleotídica do Tn3000 com aquelas disponíveis no GenBank evidencia que a mesma estrutura está presente em plasmídeos de isolados da cidade de Porto Alegre e também em diferentes continentes. As espécies de Acinetobacter (A. radioresistens, A. ursingii e A. guillouiae) isoladas em São Paulo e Porto Alegre, possuem o gene blaNDM-1 albergados em um mesmo plasmídeo não tipável de 41.087 pb. A avaliação da clonalidade dos isolados de Enterobacter hormaechei \"subsp. oharae\" mostrou dois perfis diferentes através da técnica de PFGE, sendo que todos os microrganismos foram isolados de um surto no mesmo hospital no Rio de Janeiro. Isolados de Klebsiella pneumoniae de uma mesma paciente internada em hospital em Salvador, de sítios distintos - swab retal, hemocultura e urina, em ordem cronológica - obtiveram o mesmo perfil clonal pela técnica de PFGE. O mesmo ocorreu com três isolados de Escherichia coli, de um mesmo paciente do Rio de Janeiro, em amostras de swab retal. Os achados deste estudo evidenciam que no Brasil, Nepal, Marrocos e Índia há uma disseminação do gene blaNDM-1 mediada por um novo elemento móvel designado Tn3000 em enterobactérias. A detecção de um mesmo plasmídeo em diferentes espécies de Acinetobacter evidencia que neste gênero bacteriano, no Brasil, a disseminação do gene blaNDM-1 ocorre por conjugação.<br>Carbapenems are the antimicrobials most widely used in the empirical treatment of severe infections caused by Gram-negative bacilli. The selective pressure generated by the use of these antibiotics over the last three decades has contributed to the spread of enterobacteria and Gram-negative non-fermenting producing carbapenemases, mainly KPC and NDM. Genes encoding these enzymes are usually located in plasmids and/or transposons. Currently the most accepted hypothesis is that the blaNDM-1 gene is a chimera created in Acinetobacter baumannii. The NDM-1 was described in a patient from India and subsequently was reported to be broadly disseminate in this country. The epidemiology that has been observed in cases detected in Europe and United States is traveling to India, but no autochthonous cases. In Brazil, the first cases were identified in Rio Grande do Sul, and then in Rio de Janeiro and São Paulo. Differently from the cases described in Europe and North America, the cases from Brazil have no epidemiological link with India. The complete sequencing of plasmids and chromosomes harboring blaNDM gene will understanding how the dissemination of this resistance mechanism in Brazil occurs. In this work we will be evaluate the susceptibility profile of the isolates, and their conjugal capacity and clonality. Of the twenty-eight samples used in this study, thirteen of them belong to the species Enterobacter hormaechei, one to Citrobacter freundii, seven to Escherichia coli, four to Klebsiella pneumoniae and three to the genus Acinetobacter sp. The first two isolates included in this study (Escherichia coli and Enterobacter hormaechei) were isolated in August 2013, from the same rectal swab sample from a patient from Rio de Janeiro that never traveled abroad. Complete sequencing of plasmid DNA using Illumina platform and annotation of both plasmids harboring the blaNDM-1 gene revealed that they belong to different incompatibility groups, IncFIIK (E. hormaechei) and IncX3 (E. coli), and are harbor to a new transposon designated Tn3000. The comparison of the Tn3000 nucleotide sequence with those available at GenBank shows that the same structure is present in plasmids from other Porto Alegre and also in different continents. The Acinetobacter species (A. radioresistens, A. ursingii and A. guillouiae) isolated in São Paulo and Porto Alegre, have the blaNDM-1 gene harbored in a single non-typing plasmid of 41,087 bp. The evaluation of clonal relationship of Enterobacter hormaechei \"subsp. oharae\" showed two different profiles by PFGE technique; of note all microorganisms were isolated from an outbreak in the same hospital in Rio de Janeiro. Isolates of Klebsiella pneumoniae from a single patient hospitalized in Salvador, from different anatomical sites - rectal swab, blood culture and urine, in chronological order - obtained the same clonal profile by the PFGE technique. The same occurred with three Escherichia coli isolates, from the same patient from Rio de Janeiro, in swab rectal strains. Our findings suggest that in Brazil, Nepal, Morocco and India there is a spread of blaNDM-1 gene mediated by Tn3000 in enterobacteria. The detection of a same plasmid in different species of Acinetobacter shows that in this bacterial genus, in Brazil, the dissemination of the blaNDM-1 gene occurs by conjugation.

Agricultural lands are being polluted with different contaminants due to various anthropogenic activities like toxic discharge from Ni-Cd battery industry, tannery industry, alloying of metals like steel, application of agrochemicals, etc. Cadmium and lead contamination in agricultural land are directed towards global food insecurity. Bioremediation, stress alleviation, and phytostimulation by Cd and Pb tolerant PGPR is a promising eco-friendly method to develop sustainable agricultural system. At present, cadmium and lead-tolerant plant growth promoting rhizobacteria (PGPR) can be a sustainable option for heavy metal-contaminated agricultural lands. PGPRs such as Bacillus, Bradyrhizobium, Enterobacter, Klebsiella, Micrococcus, Pseudomonas, Ralstonia, etc. can survive the metal stress and stimulate the plant growth under Cd and Pb contaminated condition by direct or indirect plant growth promoting ability. So, these PGPRs could be exploited as biofertilizers and bioremediators under Cd or Pb stressed conditions for futuristic agricultural development.

Chromium-like heavy toxic metals seriously influence the metabolism of living organisms and cause permanent threatening of health. Microorganisms can help to detoxify those hazardous heavy metals in the environment by the process of bioremediation. Two bacterial genera were isolated from industrial sludge designated P1 and P2. From the 16srRNA study, it is revealed that P1 is Bacillus cereus and P2 is Enterobacter sp. They are deposited in NCMR and NCBI and received the accession no. MCC 3868 for P1 and MCC 3788 for P2. P1 is gram positive, motile, and P2 is gram negative, motile. Eighteen antibiotics have been taken for antibiotic assay; P1 is resistant to 12; P2 is resistant to 8 antibiotics. For growth pattern analysis in chromium, three parameters have been selected, and they are temperature, pH, and biomass. In LD50 and above parameters, total chromium uptake by those bacteria in stressed conditions have been recorded. The two bacteria are not antagonistic to each other so they are used to bioremediate chromium from their contaminated sites and also treated as consortium.

Chromium-like heavy toxic metals seriously influence the metabolism of living organisms and cause permanent threatening of health. Microorganisms can help to detoxify those hazardous heavy metals in the environment by the process of bioremediation. Two bacterial genera were isolated from industrial sludge designated P1 and P2. From the 16srRNA study, it is revealed that P1 is Bacillus cereus and P2 is Enterobacter sp. They are deposited in NCMR and NCBI and received the accession no. MCC 3868 for P1 and MCC 3788 for P2. P1 is gram positive, motile, and P2 is gram negative, motile. Eighteen antibiotics have been taken for antibiotic assay; P1 is resistant to 12; P2 is resistant to 8 antibiotics. For growth pattern analysis in chromium, three parameters have been selected, and they are temperature, pH, and biomass. In LD50 and above parameters, total chromium uptake by those bacteria in stressed conditions have been recorded. The two bacteria are not antagonistic to each other so they are used to bioremediate chromium from their contaminated sites and also treated as consortium.

Heavy metals accumulated the earth crust and causes extreme pollution. Accumulation of rich concentrations of heavy metals in environments can cause various human diseases which risks health and high ecological issues. Mercury, arsenic, lead, silver, cadmium, chromium, etc. are some heavy metals harmful to organisms at even very low concentration. Heavy metal pollution is increasing day by day due to industrialization, urbanization, mining, volcanic eruptions, weathering of rocks, etc. Different microbial strains have developed very efficient and unique mechanisms for tolerating heavy metals in polluted sites with eco-friendly techniques. Heavy metals are group of metals with density more than 5 g/cm3. Microorganisms are generally present in contaminated sites of heavy metals and they develop new strategies which are metabolism dependent or independent to tackle with the adverse effects of heavy metals. Bacteria, Algae, Fungi, Cyanobacteria uses in bioremediation technique and acts a biosorbent. Removal of heavy metal from contaminated sites using microbial strains is cheaper alternative. Mostly species involved in bioremediation include Enterobacter and Pseudomonas species and some of bacillus species too in bacteria. Aspergillus and Penicillin species used in heavy metal resistance in fungi. Various species of the brown algae and Cyanobacteria shows resistance in algae.

Phytohormones are chemicals released by plants for several mechanism which includes growth and development such as cell divisions, cell elongation and tissue differentiation, it also helps in stress tolerance and senescence. Major phytohormone groups include auxin, cytokinin, gibberellin, ethylene, abscisic acid, brassinosteroids and jasmonates. Phytohormones are naturally produced in low concentration. Certain naturally available soil microorganisms produce phytohormones, the current approach of plant growth regulators to crops improve yield by dual activity and genetic modifications is highly beneficial. The pilot study on metagenomic analysis on commercially important crops helped us to expand the study on identifying the nitrogen fixing bacteria also promoting phytohormone production. Expected outcome: Agrobacterium, Azospirillum, Bacillus, Enterobacter, Pseudomonas, Proteus, Klebsiella and Mycorrhizal are microorganisms that play dual activity. All these growth-promoting bacteria are proven to be involved in indole-3-acetic acid pathways which help in the biosynthesis of auxin and cytokinin. The dual benefit of the plant-growth promoting bacteria is that it can act as a diazotroph which helps in nitrogen fixation as well as the biosynthesis of phytohormones. Several microorganisms play crucial role in plants as nitrogen-fixing bacteria, phytohormone production, etc. they play multiple function in plant growth and development. These are essential microbes in application field of agriculture and biotechnology.

As infecções do sítio cirúrgico (ISC) ainda estão entre as principais causas de morbidade e mortalidade de pacientes no pós-operatório. Devido à importância da infecção do sítio cirúrgico em pequenos animais, objetivou-se com esta revisão de literatura evidenciar os aspectos gerais e fatores associados a ISC, além dos microrganismos envolvidos e sua resistência aos antimicrobianos. A ISC muitas vezes pode estar associada ao tipo de procedimento cirúrgico, por isto é importante a classificação e cuidados para cada tipo de cirurgia (limpa, potencialmente contaminada e contaminada) que será realizada. Os fatores intrínsecos e extrínsecos também devem ser avaliados, uma vez que cirurgias contaminadas e longas em animais imunodeficientes ou que não receberam antibioticoprofilaxia, podem se tornar mais susceptíveis aos processos de ISC. Diversos microrganismos podem causar ISC, entretanto, os gêneros bacterianos mais frequentes são: Staphylococcus, Escherichia, Enterococcus, Bacillus, Shigella, Citrobacter, Proteus, Morganella, Serratia, Enterobacter, Pseudomonas e Klebsiella. Destes gêneros, Staphylococcus se destaca, principalmente as espécies Staphylococcus aureus e S. pseudintermedius resistentes à meticilina, que são consideradas mundialmente espécies de grande risco a saúde humana e animal. Portanto, é de extrema importância estabelecer o conhecimento epidemiológico dos microrganismos envolvidos em casos de ISC, bem como, realizar o seu monitoramento em relação a sua frequência e resistência antimicrobiana, garantindo a promoção da saúde para os animais submetidos a procedimentos cirúrgicos.

The present chapter aims to overview the application of silver nanoparticles (AgNPs) in photocatalysis and biomedical field. Firstly, the relevance of AgNPs will be addressed. Then, the discussion about the photocatalytic activity of the AgNPs (either in suspension or impregnation), and correlation with your properties and its potential application to organic pollutants degradation under UV and visible/solar radiation will be described. Thus, applications of the AgNPs as antimicrobial agents, such as Escherichia coli, Schizophyllum commune, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Haemophilus influenzae, Bacillus subtilis, Bacillus cereus and Enterobactor faecalis, and in the development of biosensors will be discussed. Therefore, the present work will be important to contextualize different scenarios to AgNPs mainly to wastewater treatment and diagnosis/therapeutic applications.

This chapter discusses the taxonomy of non-Bacillus and Pseudomonas (NBP) bioprotectant strains, including enterobacteria, actinomycetes, Sphingomonas, Methylobacterium, Agrobacterium-Rhizobium and Lactobacillus. The chapter reviews their mechanisms of action against plant pathogens. Sources of isolates and methods of isolation are discussed in building strain collections. The chapter then reviews procedures for screening antagonistic bacteria candidates as bioprotectants using biochemical and molecular markers, including the example of lactic acid bacteria. The chapter then covers strain improvement to increase fitness and efficacy in the field through physiological and genetic manipulation. Since they are essential for commercial development, biosafety issues are discussed, followed by an overview of patented substances and commercialized products. The chapter concludes with a summary and future trends in research on non-Bacillus and Pseudomonas species.

Surfaces and devices in public institutions are likely to be contaminated with various microorganisms as people congregate there for various reasons. Swab samples from devices like ATMs, seats, teller counters, door handles, pens, writing desks, toilet flush handles, and tap heads were obtained from banks and churches. 60 samples in all were cultured and isolates were identified using Gram stain reaction, morphological, and biochemical characteristics. Results indicated a 100% microbial contamination on all surfaces with Staphylococcus aureus having the highest frequency, 35(31.5%). Bacilli spp had the next highest frequency, 23(20.7%). Klebsiella spp 13 (11.7%), Salmonella spp 13(11.7%), Enterobacter spp 13(11.7%), Serratia spp 6(5.4%), Citrobacter spp 4(3.6%), Proteus 3(2.8%) and Streptococcus 1(0.90%) followed in that order. Commonly used public facilities' devices could serve as potential sources of infections due to their microbial contamination. It is highly recommended amidst this pandemic to have frequent proper hand hygiene to avoid unknowing contamination.

The results of following biofungicides usage on sunflower against Alternaria blight, Embellisia blight, phomosis, phomopsis in Western Region of Ukraine proposed in present paper. Among them were MicoHelp – liquid (fungi genus Trichoderma, bacterium Bacillus subtilis, Azotobacter, Enterobacter, Enterococcus, titer not less than 1,0×109 CFU/cm3), (1,0l/t); Gliocladyn BT- liquid (Gliocladium virens, titer – 1,5·109 CFU/cm3), (2,0 l/t); Trichopsin BT-liquid(fungi spores Trichoderma viride Т-4 and bacterium Pseudomonas aureofaciens 306;titer not less 2,0х1010 CFU/cm3), (2,5l/t) separately or in combination with plant growing regulator Agrostimulin (25 ml/t).The researches results showed that the used preparations favored the plant disease defeating and increase yield crop on 11,2 – 16,1%.

Rapid detection of pathogens and hazardous elements in fresh fruits and vegetables after harvest requires the use of advanced sensor technology at each step in the farm-to-consumer or farm-to-processing sequence. Fourier-transform infrared (FTIR) spectroscopy and the complementary Raman spectroscopy, an advanced optical technique based on light scattering will be investigated for rapid and on-site assessment of produce safety. Paving the way toward the development of this innovative methodology, specific original objectives were to (1) identify and distinguish different serotypes of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Bacillus cereus by FTIR and Raman spectroscopy, (2) develop spectroscopic fingerprint patterns and detection methodology for fungi such as Aspergillus, Rhizopus, Fusarium, and Penicillium (3) to validate a universal spectroscopic procedure to detect foodborne pathogens and non-pathogens in food systems. The original objectives proposed were very ambitious hence modifications were necessary to fit with the funding. Elaborate experiments were conducted for sensitivity, additionally, testing a wide range of pathogens (more than selected list proposed) was also necessary to demonstrate the robustness of the instruments, most crucially, algorithms for differentiating a specific organism of interest in mixed cultures was conceptualized and validated, and finally neural network and chemometric models were tested on a variety of applications. Food systems tested were apple juice and buffer systems. Pathogens tested include Enterococcus faecium, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Yersinia enterocolitis, Shigella boydii, Staphylococus aureus, Serratiamarcescens, Pseudomonas vulgaris, Vibrio cholerae, Hafniaalvei, Enterobacter cloacae, Enterobacter aerogenes, E. coli (O103, O55, O121, O30 and O26), Aspergillus niger (NRRL 326) and Fusarium verticilliodes (NRRL 13586), Saccharomyces cerevisiae (ATCC 24859), Lactobacillus casei (ATCC 11443), Erwinia carotovora pv. carotovora and Clavibacter michiganense. Sensitivity of the FTIR detection was 103CFU/ml and a clear differentiation was obtained between the different organisms both at the species as well as at the strain level for the tested pathogens. A very crucial step in the direction of analyzing mixed cultures was taken. The vector based algorithm was able to identify a target pathogen of interest in a mixture of up to three organisms. Efforts will be made to extend this to 10-12 key pathogens. The experience gained was very helpful in laying the foundations for extracting the true fingerprint of a specific pathogen irrespective of the background substrate. This is very crucial especially when experimenting with solid samples as well as complex food matrices. Spectroscopic techniques, especially FTIR and Raman methods are being pursued by agencies such as DARPA and Department of Defense to combat homeland security. Through the BARD US-3296-02 feasibility grant, the foundations for detection, sample handling, and the needed algorithms and models were developed. Successive efforts will be made in transferring the methodology to fruit surfaces and to other complex food matrices which can be accomplished with creative sampling methods and experimentation. Even a marginal success in this direction will result in a very significant breakthrough because FTIR and Raman methods, in spite of their limitations are still one of most rapid and nondestructive methods available. Continued interest and efforts in improving the components as well as the refinement of the procedures is bound to result in a significant breakthrough in sensor technology for food safety and biosecurity.