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1
Lin, Ying-Chuan. "Production, Location, and Binding of Violacein in Janthinobacterium." Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc798326/.
Testo completoAbstract (sommario):
Violacein is a purple pigment typically produced by species of Chromobacterium and Janthinobacterium. A soil isolate, identified as as Janthinobacterium, was studied. Maximal pigmentation ocurred at 25°C under aerobic conditions in the Keeble and Cross medium.
2
Abusada, Gabi M. (Gabi Michael). "Studies on the Mechanism of Protection by Carotenoids Against Photodynamic Killing in Curtobacterium Flaccumfaciens Pathover Poinsettiae." Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc332581/.
Testo completoAbstract (sommario):
The mechanism of protection by carotenoids against photodynamic killing in Curtobacterium flaccumfaciens pathover poinsettiae (C. poinsettiae) was studied using pigment mutants isolated by treatment with nitrosoguanidine and DNA gyrase inhibitors. Growth rates, pigment composition, pigment levels and the ultrastructure of the wild-type streptomycin resistant strain of G. poinsettiae (wt-str) and all mutants were compared. One mutant, NTG-1, lacked colored carotenoids, and another, NTG-2, was a slow growing mutant containing low levels (14%) of wild-type carotenoid pigments. Except for NTG-1, the other pigment mutants had different proportions of the same pigments found in the wild type as determined by high performance liquid chromatography (HPLC). Only NTG-2 was morphologically distinct at the ultrastructural level.
3
Campbell, Alan L. (Alan Lee). "The Genetics of Pigmentation in Corynebacterium poinsettiae ATCC 9682." Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc330778/.
Testo completoAbstract (sommario):
Corynebacterium poinsettiae mutant strains blocked in carotenoid biosynthesis were obtained by treatment with the mutagen N-methyl-N1-nitro-N-nitrosoguanidine. Additional carotenoid (Crt) mutant strains were obtained from a previous study conducted in our laboratory. Fifty-nine Crt mutants affected in carotenoid biosynthesis were examined by a normal phase high performance liquid chromatography (HPLC) system. Pigment extracts of Crt mutants and C. poinsettiae wild type strains were resolved by an isocratic system with hexane:acetone:dicholoromethane, 11.35:1.73:1.00 (by vol.) as the eluting solvent. In addition to the five major peaks, twelve minor peaks were observed in the wild type C. poinsettiae strain used in this study. Crt mutant and wild type strain peak heights were measured from the individual chromatograms and the peak height data set created was analyzed using the Statistical Analysis System program to perform a cluster analysis. The cluster analysis revealed five carotenoid mutant groups. Carotenoid pigments which accumulated or were absent in each of the cluster groups are reported. Cluster group 1 mutants (CrtA) are blocked in the dehydrogenase(s) which is(are) responsible for the dehydrogenations between phytoene and lycopene. Cluster group 2 mutants (CrtB) appear to be blocked at a second dehydrogenase specific for the dehydrogenation from C.p. 470 to C.p. 496. Cluster group 3 mutants (CrtC) are blocked at a cyclization step in the pathway which involves cyclization of C.p. 496 to C.p. 470 and which may cyclize C.p. 473 to C.p. 450. The genes CrtA and CrtB map only 0.5 map units from each other while CrtA and CrtC map 2.1 map units from one another. Mutants which accumulate end products but which lack certain precursors indicate a branched pathway for pigment biosynthesis exists in this organism. Media for the formation, fusion and regeneration of C. poinsettiae protoplasts are reported and a protocol for the use of these media in genetic crosses of strains blocked in carotenoid biosynthesis is described. While isolating antibiotic resistant mutants useful in genetic analyses, novobiocin resistant mutants were observed to have a distinctly different colony pigment phenotype as compared to the wild type strain. HPLC chromatograms of a novobiocin resistant strain showed a distinctly different carotenoid pigment profile. The results provide evidence for differential gene expression in the carotenoid biosynthetic pathway when these mutants are grown in the presence of novobiocin.
4
Egan, Suhelen Microbiology & Immunology UNSW. "Production and regulation of fouling inhibitory compounds by the marine bacterium Pseudoalteromonas tunicata." Awarded by:University of New South Wales. Microbiology and Immunology, 2001. http://handle.unsw.edu.au/1959.4/17838.
Testo completoAbstract (sommario):
The marine surface-associated bacterium Pseudoaltermonas tunicata, produces a range of compounds that inhibit fouling organisms, including invertebrate larvae, bacteria, algal spores and fungi. In addition to these antifouling compounds P. tunicata cells produce both a yellow and a purple pigment. The aim of this study was to further characterise the antifouling activities, their regulation and relationship with pigmentation, and the ecological significance of P. tunicata and related organisms. It was discovered that the anti-algal compound was extracellular, heat sensitive, polar and between 3 and 10 kDa in size. The anti-fungal compound was found to be the yellow pigment and active against a wide range of fungal and yeast isolates. Chemical analysis suggests that this compound consists of a carbon ring bound to a fatty-acid side chain. Genetic analysis supports the chemical data for the active compound as a mutant in a gene encoding for a long-chain fatty-acid CoA ligase was deficient for anti-fungal activity. To address the regulation of antifouling compounds and their relationship to pigmentation transposon mutagenesis of P. tunicata was performed. Mutants lacking the yellow pigment displayed a reduced ability to inhibit fouling organisms. Further analysis of these mutants identified genes involved with the synthesis and regulation of synthesis of pigment and antifouling compounds. One of these mutants was disrupted in a gene (wmpR) with similarity to the transcriptional regulators ToxR from Vibrio cholerae and CadC from Escherichia coli. Analysis of global protein expression using two-dimensional gel electrophoresis showed that WmpR is essential for the expression of at least fifteen proteins important for the synthesis of fouling inhibitors. The ecological significance of antifouling bacteria was addressed by assessing the antifouling capabilities of a collection of bacteria isolated from different marine surfaces. Overall, isolates from living surfaces displayed more antifouling traits then strains isolated from non-living surfaces. Five dark-pigmented strains originating from the alga Ulva lactuca were further studied. Phylogenetic and phenotypic analysis revealed that they were all members of the genus Pseudoalteromonas and were closely related to P. tunicata. Two strains represented a novel species within the genus and were taxonomically defined as P. ulvae sp. nov.
5
Borrego, i. Moré Carles. "Heterogeneïtat pigmentària en bacteris fotosintètics verds: fisiologia i significació ecològica." Doctoral thesis, Universitat de Girona, 1996. http://hdl.handle.net/10803/96755.
Testo completoAbstract (sommario):
Green bacteria possess one of the most complexes antenna systems within the group of the photosynthetic microorganisms. One reason for this complexity is the high diversity of pigments antenna, the bacteriochlorophylls (BChls c, d or e), consisting of a mixture of various forms regularly arranged within the antenna units (the chlorosomes). This pigment diversity makes difficult the accurate analysis and identification of the different bacteriochlorophylls forms by the conventional spectrophotometrical techniques<br>Els bacteris verds posseeixen un dels sistemes antena més complexes dins el grup dels microorganismes fotosintètics. Una de les raons d’aquesta complexitat és l’elevada diversitat de pigments antena, especialment pel que fa a les bacterioclorofil•les (BCIs c, d o e). Cadascuna d’aquestes BCIs, que tenen diferents estructures i propietats òptiques, es composa d’una mescla de diverses formes homòlogues disposades ordenadament a l’interior de les unitats antena (clorosomes). Aquesta diversitat pigmentària dificulta enormement l’anàlisi i identificació d’aquests pigments mitjançant les tècniques espectrofotomètriques tradicionals
6
Tanniou, Anaëlle. "Etude de la production de biomolécules d'intérêt (phlorotannins, pigments, lipides) d' algues brunes modèles par des approches combinées de profilage métabolique et d'écophysiologie." Thesis, Brest, 2014. http://www.theses.fr/2014BRES0055/document.
Testo completoAbstract (sommario):
Notre étude s’inscrit dans un processus de recherche de nouveaux composés d’origine naturelle à activités biologiques avérées à partir de macroalgues brunes, avec d’éventuelles perspectives d’exploitation industrielle. Ainsi, dans un premier volet nous avons testé des méthodologies innovantes en matière d‘extraction en utilisant trois espèces d’algues brunes comme modèles. Nous avons optimisé le protocole d’extraction solide/liquide en estimant divers paramètres cruciaux qui influent sur le rendement d’extraction et sur les activités antiradicalaires des composés extraits. Soucieux de trouver une méthodologie innovante d’extraction plus « verte » répondant aux normes européennes, nous avons donc testé des méthodes d’extraction utilisant des solvants dans leur état supercritique ou sous forme pressurisés. La comparaison avec le procédé d’extraction solide/liquide nous a permis de sélectionner l’extraction par fluides pressurisés (PLE) employée avec un mélange Ethanol-Eau pour l’extraction de composés antiradicalaires avec une haute efficacité. Dans une deuxième partie nous nous sommes intéressés aux variations quantitatives et qualitatives des principales macromolécules présentes chez l’espèce invasive Sargassum muticum en Europe. L’emploi de deux techniques analytiques, RMN HR-MAS et spectroscopie IR, nous a permis d’avoir une vue d’ensemble des compartiments susceptibles de subir des variations selon la position géographique d’une même espèce à large répartition. Cette étude nous a montré comment une espèce est capable de changer sa composition biochimique en fonction de son environnement et ainsi s’acclimater à des milieux assez différents. Ce travail a mis en évidence les effets de différents paramètres environnementaux sur les compartiments lipidique (analysés en GC), protéique ainsi que sur les quantités de carbohydrates et de pigments (analysés en HPLC). L’influence de ces paramètres sur la taille des individus de Sargassum muticum a également été discutée. La dernière partie de cette étude nous a permis de décrire les variations quantitatives et qualitatives des phlorotannins chez l’espèce invasive Sargassum muticum sur une grande échelle spatiale, le long d’un gradient latitudinal (Norvège-Portugal). Dans un premier temps cette variabilité a été appréhendée grâce à un suivi temporel et spatial des teneurs en phlorotannins. L’étude des variabilités intra-spécifiques et intra-individuelles nous a permis de mettre en évidence un effet du stade de développement et de la partie de l’algue considérée : les teneurs et activités des phlorotannins sont plus importantes dans les crampons et chez les individus matures. Après la recherche d’un protocole simple pour la semi-purification des composés phénoliques présent chez Sargassum muticum, nous avons pu mettre en évidence la présence de composés de type phlorethol au moyen de techniques de RMN à deux dimensions (2D). Ces fractions semi-purifiées possèdent des activités antiradicalaire et antibactérienne notoires. Enfin, l’utilisation de plusieurs techniques de séparation membranaires nous a permis d’estimer le poids moléculaire des différents composés présents dans le pool de composés phénoliques extrait. Enfin, suite aux constats effectués sur les populations, l’effet de l’intensité lumineuse et de la température de l’eau a pu être apprécié isolément : les radiations UVA et UVB boostent la production de CP alors qu’une augmentation de la température fait chuter la production de CP chez S. muticum<br>Our study is part of the research process for new compounds of natural origin with biological activities and possible industrial perspectives. In a first part, we tested innovative extraction methodologies using three brown algae species as model. We optimized the solid/liquid extraction protocol by estimating diverse crucial parameters which influence the extraction yield and radical scavenging activities of extracts. In order to find an innovative and more "green" extraction methodology answering the European standards, we thus tested more recent extraction methods using solvents in their supercritical state or under pressure. The comparison with the solid/liquid process allowed us to select pressurized liquid extraction (PLE) using an ethanol-water mixture for the extraction of active compounds with a high efficiency, but also to select Sargassum muticum as an interesting model for further investigations. In a second part, we were interested in the quantitative and qualitative variations of the main macromolecules present in the invasive species S. muticum in Europe. The employment of two analytical techniques (NMR HR-MAS and IR spectroscopy), allowed us to have an overview of biochemical parts of the algae, which vary according to the geographical position of this wide spread species. This study showed how a species is able to modify its biochemical composition, and then to acclimate, according to the environment. We then focused on molecules, which showed important variations along the latitudinal range of S. muticum. This work highlighted the effects of environmental parameters on lipid (GC analysis) and protein compartments as well as on carbohydrates and pigments quantities (HPLC analysis). The influence of these parameters on the size of individuals was also discussed. The last part of this study allowed us to describe the quantitative and qualitative variations of phlorotannins in S. muticum on a large spatial scale, along a latitudinal gradient (Norway-Portugal). At first this variability was measured thanks to temporal and spatial follow-up of the phlorotannins contents. The study of intra-specific and intra-individual variabilities allowed us to highlight an effect of the development stage and of the seaweed part: phlorotannins contents and activities are more important in holdfast and in mature individuals. After the research of a simple protocol for the phenolic compounds semi-purification present in Sargassum muticum, we were able to highlight the presence of compounds of only phlorethol type in this species by means of 2D RMN techniques. These semi-purified fractions possess notorious radical scavenging and antibacterial activities. Finally, the use of several membrane separation techniques allowed us to consider the molecular weight of the various compounds present in the extracted pool of phenolic compounds. Finally, under controlled conditions, the effects of the light quality and the seawater temperature were tested: UV-A and UV-B radiations boost the production of CP while an increase of the temperature makes the phlorotannins production decreasing in S. muticum
7
Omer, Zahra Saad. "Bacterial-plant associations with special focus on pink-pigmented facultative mehtylotrophic bacteria (PPFMs) /." Uppsala : Dept. of Plant Pathology and Biocontrol Unit, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a456-ab.html.
Testo completo
8
Torres, Ane Pamela Capucci [UNESP]. "Biomassa bacteriana como aditivo de ração de aves e peixes." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/94595.
Testo completoAbstract (sommario):
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torres_apc_me_araca.pdf: 261452 bytes, checksum: 991e448a142886f9718c07c6963016f3 (MD5)<br>Rubrivivax gelatinosus é uma bactéria fototrófica natural de ambientes aquáticos que apresenta a capacidade de crescer em substratos contendo diversos compostos orgânicos. Neste trabalho, a biomassa da bactéria, produzida em águas residuárias provenientes de abate e processamento de pescado, foi caracterizada em relação a cor, composição centesimal, composição microbiológica e conteúdo de pigmentos carotenóides e aminoácidos, visando avaliar seu potencial como ingrediente para ração animal. Os resultados encontrados apontaram valores médios de 57% de proteína bruta, 23% de extrativo não nitrogenado e contaminantes, 11% de extrato etéreo, 5% de umidade e 4% de matéria mineral. Vários aminoácidos considerados essenciais para diversas espécies animais foram detectados no produto, tais como metionina (0,66g/100g), lisina (4,52g/100g), fenilalanina (3,43g/100g) e valina (4,39g/100g). Os resultados das análises microbiológicas indicaram contagens médias de 5,3 x 106 UFC/g para bactérias mesófilas aeróbias e facultativas viáveis, 20,27 NMP/g para coliformes a 35°C, <1,0 NMP/g para coliformes a 45°C e 1,2 x 103 UFC/g para bolores e leveduras. Não foram encontrados Aeromonas spp., Salmonella spp. e estafilococos coagulase positivo. O resultado da análise objetiva da cor da biomassa indicou valores médios de 25,48 para tonalidade, 14,22 para saturação da cor e 22,42 para luminosidade. A concentração média de carotenóides foi de 3,03 mg/g de biomassa. A determinação da composição e das características sensoriais da biomassa de Rubrivivax gelatinosus indicaram baixo nível de contaminação microbiana e alto potencial nutricional e pigmentante, apontando positivamente para sua utilização como ingrediente de rações na criação de animais<br>Rubrivivax gelatinosus is a photoautotrophic bacterium that inhabits aquatic environment in which it uses different organic substrates for growth. In this work, the biomass of the bacterium, grown in effluent from fish slaughter and processing industry was characterized for color, proximate composition, microbiological composition, carotenoids and amino acids contents, with the aim of evaluating its potential as a feed ingredient. Mean results showed 57% crude protein, 23% non nitrogen extract and contaminants, 11% ether extract, 5% moisture and 4% ashes. Many amino acids considered essential for different animal species were present in the product, like metionine (0.66g/100g), lysine (4.52g/100g), phenylalanine (3.43g/100g) and valine (4.39g/100g). Microbial analysis showed mean counts of 5.3 x 106 UFC/g for mesophilic bacteria, 20.27 NMP/g for coliforms at 35°C, <1.0 NMP/g for coliforms at 45°C and 1.2 x 103 UFC/g for yeasts and moulds. Aeromonas spp., Salmonella spp. and positive coagulase staphylococci were not detected in the product. Results from objective color evaluation showed means at 25.48 for hue, 14.22 for chroma and 22.42 for lightness. Mean carotenoids concentration detected was 3.03 mg/g biomass. The determination of composition and sensorial characteristics of Rubrivivax gelatinosus biomass indicated low contamination level and high nutritional and pigmenting potential, pointing out for a positive use of the product as an ingredient for animal feeds
9
Sarcina, Maria. "Pigment-protein interactions within photosystem II." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313030.
Testo completo
10
Fraser, Niall Johnston. "Modified pigments and mechanisms of energy transfer in LH2 complexes from purple bacteria." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301678.
Testo completo
11
Schwarzentruber, Patrick. "Microbiological characterisation of white pigment slurries : a strategy for bacteria management." Thesis, University of Warwick, 2003. http://wrap.warwick.ac.uk/73547/.
Testo completoAbstract (sommario):
The microbiological characterisation as well as the application of microbiocides for the storage and protection of mineral dispersions is of ever-increasing interest for scientists and industrialists and includes many challenges for the mineral slurry producer and user. Increasing conversion from dry pigment handling to water-based dispersions is taking place over a wide range of production applications, for example, papermaking filler products and coating formulations in both the paper and paint industries. The requirements for the delivery of preserved slurried products begins from the moment the mineral is extracted or synthetically produced. The process conditions are as important regarding bacterial colonisation and control as the delivery and storage strategy of the end-product itself. This thesis attempts to give a detailed insight into the background issues and procedures needed to provide an environment of "good housekeeping", essential in optimising the microbiological control needed for preservation and acceptable application of the pigment in its end-use. On this base, the latest research on the bacterial strains, their identification, measurement and growth dynamics in real-time are presented, and new biocide strategies, applicability and constraints are discussed. Illustrations are given throughout of the sources of microbiological contamination likely to occur during production, storage and transportation. Based on the current knowledge being gained from combining active Research and Development and on the ground applications expertise, new possibilities for optimising microbiological quality control are described.
12
Jacobs, Anelet. "Investigation and comparison of adherence- and biofilm-forming capacities of yellow-pigmented Chryseobacterium, Elizabethkingia and Myroides spp. isolated from South African aquaculture systems." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/19634.
Testo completoAbstract (sommario):
Thesis (MSc)--University of Stellenbosch, 2007.<br>ENGLISH ABSTRACT: In the aquaculture setting, opportunistic pathogens are present as part of the normal
aquatic microflora, colonizing surfaces in fish tanks as part of biofilm communities, and
often causing severe economic losses to the aquacultural industry. Isolates belonging to
the genera Chryseobacterium, Elizabethkingia, Myroides and Empedobacter have been
isolated from diseased fish, and are responsible for causing secondary fish infections,
fish- and food-product spoilage, and have been described as etiological agents of various
human diseases. Thirty-four Chryseobacterium and Elizabethkingia spp. and five
Myroides and Empedobacter spp. isolates, obtained from various diseased fish species
and biofilm growth in South African aquaculture systems, were characterised genetically
using 16S rRNA gene PCR restriction fragment length polymorphism (RFLP), randomly
amplified polymorphic DNA (RAPD) PCR, whole cell protein (WCP) and outer
membrane protein (OMP) analyses. Genetic heterogeneity was displayed by the
Myroides and Empedobacter spp. study isolates following OMP analysis, although 16S
rRNA gene RFLP, RAPD-PCR and WCP analysis did not allow for differentiation of
these isolates. A high degree of genetic heterogeneity was displayed by the
Chryseobacterium and Elizabethkingia spp. study isolates following OMP analysis, 16S
rRNA gene RFLP with MspI, and RAPD-PCR with primer P2. However, based on the
results obtained by WCP analysis, 16S rRNA gene RFLP with CfoI and TaqI, and
RAPD-PCR with primer P1 the isolates appeared genetically very homogeneous. High
MAR indices and potential multi-drug resistance phenotypes were obtained for the
Myroides and Empedobacter spp. and some of the Chryseobacterium and Elizabethkingia
spp. isolates by antimicrobial susceptibility testing. Primary adherence and the influence
of environmental changes on adherence was investigated by a modified microtitre-plate
adherence assay. Nutrient composition, temperature and hydrodynamic incubation
conditions were observed to influence adherence abilities of all study isolates. In
addition, adherence varied greatly among isolates of the genera Chryseobacterium and
Elizabethkingia, as opposed to a consistent strong adherence profile observed for the
Myroides and Empedobacter spp. isolates. The influence of cell surface properties such
as capsule presence and cell surface hydrophobicity, on primary adherence of the isolates
was also investigated. Quantitative analysis of capsular material revealed the presence of thick capsular material surrounding the Myroides and Empedobacter spp. and some of the
Chryseobacterium and Elizabethkingia spp. isolates, but could not be directly associated
with adherence. Hydrophobicity were investigated using the salt aggregation assay
(SAT) and bacterial adherence to hydrocarbon test (BATH). A very hydrophilic cell
surface was observed for all of the Myroides and Empedobacter spp. isolates, and
majority (74%) of the Chryseobacterium and Elizabethkingia spp. isolates. Cell surface
hydrophobicity could not be correlated to the adherence of the Myroides and
Empedobacter spp. isolates, and only SAT-determined hydrophobicity could be
positively correlated to adherence of Chryseobacterium and Elizabethkingia spp. isolates
under certain conditions. Coaggregation studies were performed between the study
isolates and various important clinical and aquacultural microorganisms. High
coaggregation indices were observed between the Myroides and Empedobacter spp.
isolates and E. faecalis and S. aureus, and between E. faecalis, S. enterica serovar
Arizonae, S. aureus and Listeria spp. and the Chryseobacterium and Elizabethkingia spp.
isolates. Biofilm-forming capacity of the study isolates in an environment simulating
their natural environment was investigated microscopically using a flow cell system.
Typical ‘cone-like’ biofilm structures were observed for selected strains of both Myroides
and Empedobacter spp. and Chryseobacterium and Elizabethkingia spp. isolates. The
effect of increased hydrodynamics on biofilm architecture was seen through the
narrowing of the biofilm structures and the formation of single cell chains towards the
increased hydrodynamic area of the flow chambers. Chryseobacterium and
Elizabethkingia spp. and Myroides and Empedobacter spp. appear to be potential primary
biofilm-formers associating with a variety of microbes thus perpetuating their survival in
a variety of aquatic habitats.<br>AFRIKAANSE OPSOMMING: Opportunistiese patogene kom gereeld in akwakultuur sisteme voor as deel van die
akwatiese mikroflora wat dikwels biofilms vorm op oppervlaktes in hierdie sisteme.
Visinfeksies veroorsaak deur hierdie patogene lei tot ernstige ekonomiese verliese vir
akwakultuur industrieë. Chryseobacterium, Elizabethkingia, Myroides en Empedobacter
spp. is reeds voorheen van verskeie geïnfekteerde visspesies geïsoleer hierdie bakterieë is
verantwoordelik vir sekondere visinfeksies, die bederf van vis- en kosprodukte, asook
menslike siektes. Vier-en-dertig Chryseobacterium en Elizabethkingia spp. en 5
Myroides en Empedobacter spp. isolate, geïsoleer vanaf verskeie geïnfekteerde visspesies
en biofilm-groei in Suid Afrikaanse akwakultuur-sisteme, is geneties met behulp van 16S
rRNS geen PKR restriksie fragment lengte polimorfisme (RFLP), toevallig
geamplifiseerde polimorfiese DNS (TGPD) PKR, heel-sel protein (HSP) en buitemembraan
protein (BMP) analise gekarakteriseer. BMP analise het getoon dat die
Myroides en Empedobacter spp. isolate geneties heterogeen is, alhoewel 16S rRNS
TGPD-PKR, TGPD-PKR en HSP analise nie tussen die isolate kon onderskei nie. BMP
analise, 16S rRNS TGPD-PKR met MspI en TGPD-PKR met inleier P2 was meer
suksesvol as HSP analise, 16S rRNS TGPD-PKR met CfoI en MspI, en TGPD-PKR met
inleier P1, om onderskeid te tref tussen die Chryseobacterium en Elizabethkingia spp.
isolate en het gedui op ‘n hoë vlak van genetiese heterogeniteit tussen hierdie isolate.
Beide die Chryseobacterium en Elizabethkingia spp. en Myroides en Empedobacter spp.
isolate het ‘n hoë vlak van antibiotika weerstand getoon wat dui op ‘n menigvuldigde
antibiotika weerstands-fenotiepe. Primêre vashegting vermoëns en die invloed van
omgewingsfaktore op vashegting is met behulp van ‘n gemodifiseerde mikrotiterplaat
vashegtings toets ondersoek. Vashegting van die isolate is beïnvloed deur variasies in die
samestelling van die medium, temperatuurveranderings en verskillende hidrodinamiese
inkubasie kondisies. Inteenstelling met die sterk vashegtingsvermoë van die Myroides en
Empedobacter spp. isolate, het die vermoë om vas te heg grootliks tussen die
Chryseobacterium en Elizabethkingia spp. isolate gevarieer. Verder is ondersoek ingestel
op die invloed van seloppervlak eienskappe soos die teenwoordigheid van kapsules en
hidrofobisiteit op die isolate se vermoë om aan oppervlaktes te heg. Die Myroides en Empedobacter spp. isolate en verskeie Chryseobacterium en Elizabethkingia spp. isolate
is omring deur dik kapsules, maar geen verband tussen vashegting en die
teenwoordigheid van kapsules kon bepaal word nie. Die sout aggregasie toets (SAT) en
bakteriële vashegting aan koolwaterstowwe (BVAK) toets was gebruik om die
hidrofobisiteit van die isolate se seloppervlaktes te bepaal. Die Myroides en
Empedobacter spp. isolate en 74% van die Chryseobacterium en Elizabethkingia spp.
isolate het ‘n baie hidrofiliese seloppervlak getoon. Slegs die hidrofobisiteit bepaal deur
die SAT toets het ‘n positiewe verwantskap met die aanhegtingsvermoë van die
Chryseobacterium en Elizabethkingia spp. isolate getoon. Mede-aggregasie tussen die
isolate en verskeie belangrike mediese en akwakultuur mikroörganismes is ook
ondersoek. Die Myroides en Empedobacter spp. isolate het ‘n sterk assosiasie met E.
faecalis en S. aureus getoon Die Chryseobacterium en Elizabethkingia spp. isolate het
sterk met E. faecalis, S. aureus, S. enterica serovar Arizonae en Listeria spp. geassosieer.
Vloei-sel studies is uitgevoer om die biofilm-vormingsvermoë van die isolate te
ondersoek. Vir beide die Myroides en Empedobacter spp. en Chryseobacterium en
Elizabethkingia spp. isolate is tipiese kegelagtige biofilm stukture waargeneem. Die
invloed van verhoogde hidrodinamiese kondisies in die vloei-sel het vernouing van die
biofilm strukture en die vorming van enkel-sel kettings tot gevolg gehad. Vanuit hierdie
studie is afgelei dat die Myroides en Empedobacter spp. en Chryseobacterium en
Elizabethkingia spp. isolate onder verskeie kondisies aan oppervlaktes kan vasheg en dus
potensiële primêre biofilm-vormings organismses is. Hierdie organismes besit ook die
vermoë om met ‘n verskeidenheid ander organismes te assosieer, wat waarskynlik hulle
suksesvolle oorlewing in akwakultuursisteme verseker.
13
Vaitkevičius, Karolis. "Effects of Vibrio cholerae protease and pigment production on environmental survival and host interaction /." Umeå : Univ, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1474.
Testo completo
14
McDermott, Gerry. "Structural studies on an integral membrane light-harvesting complex." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337507.
Testo completo
15
Moyo, Anesu Conrad. "Biological approach to improving the evaporation rates of mine wastewater desalination brine treated in evaporation ponds." University of the Western Cape, 2021. http://hdl.handle.net/11394/7982.
Testo completoAbstract (sommario):
Philosophiae Doctor - PhD<br>The disposal of brine effluent from inland wastewater desalination plants is a
growing global problem with adverse economic and environmental implications
because of the substantial cost associated with its disposal and the potential for
polluting groundwater resources. Currently, the best and most economical option
for brine disposal from inland desalination plants is the use of evaporation ponds,
which concentrate the liquid until getting a solid waste that can be valued or
directly managed by an authorized company. The effectiveness of these ponds is
therefore dependent on the evaporation rate, which has previously been improved
by the addition of dyes such as methylene blue. However, the addition of chemical
dyes to the evaporation ponds poses a threat to the environment, wildlife, and
humans.
16
Torres, Ane Pamela Capucci. "Biomassa bacteriana como aditivo de ração de aves e peixes /." Araçatuba : [s.n.], 2010. http://hdl.handle.net/11449/94595.
Testo completoAbstract (sommario):
Orientador: Elisa Helena Giglio Ponsano<br>Banca: Marcelo Vasconcelos Meireles<br>Banca: Otto Mack Junqueira<br>Resumo: Rubrivivax gelatinosus é uma bactéria fototrófica natural de ambientes aquáticos que apresenta a capacidade de crescer em substratos contendo diversos compostos orgânicos. Neste trabalho, a biomassa da bactéria, produzida em águas residuárias provenientes de abate e processamento de pescado, foi caracterizada em relação a cor, composição centesimal, composição microbiológica e conteúdo de pigmentos carotenóides e aminoácidos, visando avaliar seu potencial como ingrediente para ração animal. Os resultados encontrados apontaram valores médios de 57% de proteína bruta, 23% de extrativo não nitrogenado e contaminantes, 11% de extrato etéreo, 5% de umidade e 4% de matéria mineral. Vários aminoácidos considerados essenciais para diversas espécies animais foram detectados no produto, tais como metionina (0,66g/100g), lisina (4,52g/100g), fenilalanina (3,43g/100g) e valina (4,39g/100g). Os resultados das análises microbiológicas indicaram contagens médias de 5,3 x 106 UFC/g para bactérias mesófilas aeróbias e facultativas viáveis, 20,27 NMP/g para coliformes a 35°C, <1,0 NMP/g para coliformes a 45°C e 1,2 x 103 UFC/g para bolores e leveduras. Não foram encontrados Aeromonas spp., Salmonella spp. e estafilococos coagulase positivo. O resultado da análise objetiva da cor da biomassa indicou valores médios de 25,48 para tonalidade, 14,22 para saturação da cor e 22,42 para luminosidade. A concentração média de carotenóides foi de 3,03 mg/g de biomassa. A determinação da composição e das características sensoriais da biomassa de Rubrivivax gelatinosus indicaram baixo nível de contaminação microbiana e alto potencial nutricional e pigmentante, apontando positivamente para sua utilização como ingrediente de rações na criação de animais<br>Abstract: Rubrivivax gelatinosus is a photoautotrophic bacterium that inhabits aquatic environment in which it uses different organic substrates for growth. In this work, the biomass of the bacterium, grown in effluent from fish slaughter and processing industry was characterized for color, proximate composition, microbiological composition, carotenoids and amino acids contents, with the aim of evaluating its potential as a feed ingredient. Mean results showed 57% crude protein, 23% non nitrogen extract and contaminants, 11% ether extract, 5% moisture and 4% ashes. Many amino acids considered essential for different animal species were present in the product, like metionine (0.66g/100g), lysine (4.52g/100g), phenylalanine (3.43g/100g) and valine (4.39g/100g). Microbial analysis showed mean counts of 5.3 x 106 UFC/g for mesophilic bacteria, 20.27 NMP/g for coliforms at 35°C, <1.0 NMP/g for coliforms at 45°C and 1.2 x 103 UFC/g for yeasts and moulds. Aeromonas spp., Salmonella spp. and positive coagulase staphylococci were not detected in the product. Results from objective color evaluation showed means at 25.48 for hue, 14.22 for chroma and 22.42 for lightness. Mean carotenoids concentration detected was 3.03 mg/g biomass. The determination of composition and sensorial characteristics of Rubrivivax gelatinosus biomass indicated low contamination level and high nutritional and pigmenting potential, pointing out for a positive use of the product as an ingredient for animal feeds<br>Mestre
17
Yang, Wenbo Ms. "Effect of Chlorine Dioxide Gas Treatment on Bacterial Inactivation Inoculated on Spinach Leaves and on Pigment Content." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429609779.
Testo completo
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Murphy, Julianna E. "Catalytic Effect of Iron Oxidizing Bacteria on the Production of Pigment from Acid Mine Drainage." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou149383043673114.
Testo completo
19
Vaitkevicius, Karolis. "Effects of Vibrio cholerae protease and pigment production on environmental survival and host interaction." Doctoral thesis, Umeå universitet, Molekylärbiologi (Medicinska fakulteten), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1474.
Testo completoAbstract (sommario):
Only two out of more than 200 V. cholerae serogroups, classified on the basis of LPS structure, are associated with epidemic or pandemic cholera. These toxigenic serogroups carry phage-derived pathogenicity islands coding for the main virulence factors for establishment of cholera disease – cholera toxin (CTX) and toxin-coregulated pilus (TCP). The latter also serves as a bacterial surface receptor for the CTXΦ – the filamentous phage which carries the cholera toxin genes into otherwise harmless to human, environmental bacterium V. cholerae. In its natural aquatic habitat V. cholerae is subject to predator grazing, bacteriophage killing, temperature and pH changes, seasonality of plankton blooms and other environmental factors. Therefore understanding V. cholerae pathogenic and virulence potential requires the knowledge of its interaction not only with human host but also members of aquatic environment and environmental factors. V. cholerae is capable of killing the nematode Caenorhabditis elegans. Using a reverse genetics approach, we demonstrated that the quorum sensing regulated protease PrtV is essential for this killing. Other proteases did not seem to contribute to virulence in this model. The data from this study suggest that the PrtV could be important to V. cholerae in its natural niche for its resistance to the grazing predators. The PrtV protease belongs to an M6 family of metallopeptidases which is represented by an Immune Inhibitor A protease from the insect killing bacterium Bacillus thuringiensis. To characterize the protease in more detail, the PrtV was cloned, overexpressed in V. cholerae and purified from the culture supernatant. The enzyme was calcium stabilized and inhibited by metal ion chelators. In tests with in vitro cultured cells of the human intestinal cell line HCT8, the PrtV protein showed a cytotoxic effect leading to cell detachment and death. Using human blood plasma as a source of potential substrates, and by tests with purified candidate substrate proteins, we have identified fibrinogen (all α, β and γ chains), fibronectin and plasminogen to be degraded by the protease. Additionally, PrtV was found to alter the stability of V. cholerae cytolysin implicating its role in modulation of the reactogenicity of V. cholerae secreted factors. Pigmentation has been considered to be important in microbial pathogenesis because it has been associated with virulence in many microorganisms. Using transposon mutagenesis we identified the mutated locus of a pigment producing V. cholerae strain to encode a gene of a tyrosine catabolic pathway. The mutation in a putative homogentisate 1,2-dioxigenase gene lead to accumulation of homogentisic acid, its spontaneous oxidation and formation of a dark pigment. The pigment producing strain was altered in its ability to survive UV exposure and H2O2 stress, and was more efficient in colonizing the suckling mouse intestine compared to the wild type strain. Under the in vitro growth conditions the major virulence factor TcpA and CT expression was found to be somewhat enhanced too.
20
Grassi, Thiago Luís Magnani [UNESP]. "Qualidade de filés de tilápia alimentadas com pigmentante de origem bacteriana: Thiago Luís Magnani Grassi. -." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/124481.
Testo completoAbstract (sommario):
Made available in DSpace on 2015-07-13T12:10:22Z (GMT). No. of bitstreams: 0
Previous issue date: 2014-12-16. Added 1 bitstream(s) on 2015-07-13T12:25:19Z : No. of bitstreams: 1
000836384.pdf: 412403 bytes, checksum: 5c3371fcf3a2491bbc23d94ad1d0711f (MD5)<br>O tom avermelhado de alguns peixes age como um fator distintivo em relação ao pescado convencional de carne branca, agregando valor e propiciando o surgimento de um novo produto. Por esse motivo, o estudo de fontes pigmentantes para utilização em dietas de peixes de importância econômica é assunto de considerável interesse para a aquicultura e a indústria de alimentos. O objetivo deste trabalho foi avaliar o efeito de diferentes fontes de carotenoides adicionados à ração de tilápias sobre o desempenho zootécnico e as características de qualidade dos filés. Novecentas e sessenta tilápias (Oreochromis niloticus) pesando entre 10 - 30 g foram distribuidas em 24 tanques e, após um período de adaptação, receberam as rações experimentais durante 80 dias. Os tratamentos foram constituídos de um grupo controle, correspondente a uma dieta basal sem aditivos pigmentantes, um grupo contendo astaxantina e quatro grupos contendo diferentes concentrações da biomassa de Rubrivivax gelatinosus como aditivo pigmentante. As variáveis analisadas incluíram consumo de ração, ganho de peso e conversão alimentar aparente das tilápias e pH, composição centesimal, concentração de carotenoides e cor dos filés. Os índices zootécnicos não diferiram estatisticamente, indicando que o uso dos pigmentantes não causou prejuízo ao desempenho produtivo. Os teores de umidade dos grupos que receberam pigmentantes foram inferiores aos encontrados nos filés do grupo controle, sendo este resultado relevante para a estabilidade microbiológica. O teor proteico dos filés dos grupos suplementados com biomassa bacteriana foi superior ao do grupo controle e os valores de pH, cinzas e lipídeos não variaram entre os tratamentos. A luminosidade e a intensidade de amarelo dos filés não diferiram entre os grupos e todos os tratamentos contendo pigmentantes provocaram aumento na intensidade...(Resumo completo, clicar acesso eletrônico abaixo)<br>The reddish hue of some fish acts as a distinctive factor from traditional white flesh, adding value to the product and providing a new product to consumer market. Because of that, the investigation on pigmenting sources for the diets of fish with economic importance is a matter of great interest for aquaculture and food industry. The aim of this work was to evaluate the effects of different carotenoids sources in tilapia fish diets on animals' performance and fillets characteristics. Nine hundred sixty tilapias (Oreochromis niloticus) weighing 10 - 30 g were distributed in 24 tanks and, after an adaptation time, they received the experimental diets for 80 days. Treatments consisted of one control group receiving a basal diet with no pigment, one group receiving asthaxanthin and four groups receiving different concentrations of Rubrivivax gelatinosus biomass as the pigmenting ingredient. Variables analyzed included feed consumption, weight gain and feed conversion for the animals and pH, proximate composition, carotenoids content and color for the fillets. Productive parameters did not differ statistically, showing that the use of the pigments did not cause any damage to animals' performance. Moisture contents of the fillets from the groups that received pigments were lower than those in the fillets from control group, what represents an important factor for the product conservation. The protein contents of the fillets from diets supplemented with the bacterial biomass were higher than those in control group while pH, ash and lipids did not vary among treatments. Lightness and yellowness did not differ among the groups but redness and carotenoids contents were higher for the fillets from all groups that received the pigments than for the control group. So, it can be concluded that the use of the pigmenting ingredients did not alter productive parameters but increased...(Complete abstract eletronic access below)
21
Grassi, Thiago Luís Magnani. "Qualidade de filés de tilápia alimentadas com pigmentante de origem bacteriana / Thiago Luís Magnani Grassi. -." Araçatuba, 2014. http://hdl.handle.net/11449/124481.
Testo completoAbstract (sommario):
Orientador: Elisa Helena Giglio Ponsano<br>Banca:Rachel Cristina Prehl Alves<br>Banca: Silvia Helena Venturoli Perri<br>Resumo: O tom avermelhado de alguns peixes age como um fator distintivo em relação ao pescado convencional de carne branca, agregando valor e propiciando o surgimento de um novo produto. Por esse motivo, o estudo de fontes pigmentantes para utilização em dietas de peixes de importância econômica é assunto de considerável interesse para a aquicultura e a indústria de alimentos. O objetivo deste trabalho foi avaliar o efeito de diferentes fontes de carotenoides adicionados à ração de tilápias sobre o desempenho zootécnico e as características de qualidade dos filés. Novecentas e sessenta tilápias (Oreochromis niloticus) pesando entre 10 - 30 g foram distribuidas em 24 tanques e, após um período de adaptação, receberam as rações experimentais durante 80 dias. Os tratamentos foram constituídos de um grupo controle, correspondente a uma dieta basal sem aditivos pigmentantes, um grupo contendo astaxantina e quatro grupos contendo diferentes concentrações da biomassa de Rubrivivax gelatinosus como aditivo pigmentante. As variáveis analisadas incluíram consumo de ração, ganho de peso e conversão alimentar aparente das tilápias e pH, composição centesimal, concentração de carotenoides e cor dos filés. Os índices zootécnicos não diferiram estatisticamente, indicando que o uso dos pigmentantes não causou prejuízo ao desempenho produtivo. Os teores de umidade dos grupos que receberam pigmentantes foram inferiores aos encontrados nos filés do grupo controle, sendo este resultado relevante para a estabilidade microbiológica. O teor proteico dos filés dos grupos suplementados com biomassa bacteriana foi superior ao do grupo controle e os valores de pH, cinzas e lipídeos não variaram entre os tratamentos. A luminosidade e a intensidade de amarelo dos filés não diferiram entre os grupos e todos os tratamentos contendo pigmentantes provocaram aumento na intensidade...(Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The reddish hue of some fish acts as a distinctive factor from traditional white flesh, adding value to the product and providing a new product to consumer market. Because of that, the investigation on pigmenting sources for the diets of fish with economic importance is a matter of great interest for aquaculture and food industry. The aim of this work was to evaluate the effects of different carotenoids sources in tilapia fish diets on animals' performance and fillets characteristics. Nine hundred sixty tilapias (Oreochromis niloticus) weighing 10 - 30 g were distributed in 24 tanks and, after an adaptation time, they received the experimental diets for 80 days. Treatments consisted of one control group receiving a basal diet with no pigment, one group receiving asthaxanthin and four groups receiving different concentrations of Rubrivivax gelatinosus biomass as the pigmenting ingredient. Variables analyzed included feed consumption, weight gain and feed conversion for the animals and pH, proximate composition, carotenoids content and color for the fillets. Productive parameters did not differ statistically, showing that the use of the pigments did not cause any damage to animals' performance. Moisture contents of the fillets from the groups that received pigments were lower than those in the fillets from control group, what represents an important factor for the product conservation. The protein contents of the fillets from diets supplemented with the bacterial biomass were higher than those in control group while pH, ash and lipids did not vary among treatments. Lightness and yellowness did not differ among the groups but redness and carotenoids contents were higher for the fillets from all groups that received the pigments than for the control group. So, it can be concluded that the use of the pigmenting ingredients did not alter productive parameters but increased...(Complete abstract eletronic access below)<br>Mestre
22
Robert, Bruno. "Etude de la structure et des interactions au sein des complexes proteine pigments impliques dans la photosynthese bacterienne : contribution de la spectrometrie raman de resonance." Paris 6, 1987. http://www.theses.fr/1987PA066603.
Testo completo
23
Cabrera, Juan Carlos. "DARK-PIGMENTED, AMOXICILLIN-RESISTANT, BACTERIAL SPECIES IN CHRONIC PERIODONTITIS MICROBIOTA IDENTIFIED WITH MATRIX ASSISTED LASER DESORPTION/IONIZATION TIME-OF-FLIGHT MASS SPECTROMETRY." Master's thesis, Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/311087.
Testo completoAbstract (sommario):
Oral Biology<br>M.S.<br>Dark-pigmented, gram-negative, anaerobic rods are often recovered in large numbers from the subgingival microbiome of human periodontitis, and are statistically associated with progression of chronic periodontitis. Due to their frequent expression of beta-lactamase enzymes, which hydrolyze and degrade beta-lactam class antibiotics, these species may compromise systemic periodontal antimicrobial chemotherapy involving amoxicillin, which may lead to clinical therapeutic failures in chronic periodontitis therapy. Recent studies using phenotypic methods have identified the in vitro growth of Prevotella intermedia/nigrescens in the presence of therapeutic threshold concentrations of amoxicillin, which is indicative of species antibiotic resistance. Because of uncertainties with their taxonomic classification, only limited information is available on the distribution of amoxicillin-resistant species within the group of dark-pigmented, gram-negative, anaerobic rods that may colonize and inhabit human subgingival sites. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and its associated analytic software, was recently approved for clinical microbiology diagnostic use in the United States by the United States Food and Drug Administration. This methodology is capable of definitively identifying 4,613 different oral and non-oral microbial species based on mass spectra of their bacterial protein profiles, including many dark-pigmented, gram-negative, anaerobic rods of subgingival origin. However, MALDI-TOF mass spectrometry has yet to be used for species iii identification of dark-pigmented, gram-negative, anaerobic rods recovered from chronic periodontitis lesions, and resistant in vitro to amoxicillin. As a result, the purpose of this study was to use MALDI-TOF mass spectrometry to identify to a species-level the patient distribution of dark-pigmented, gram-negative, anaerobic rods isolated from the subgingival microbiota of chronic periodontitis patients and exhibiting in vitro resistance to therapeutic concentrations of amoxicillin. Methods: 24 chronic periodontitis patients contributed 71 fresh subgingival cultivable isolates (one to 11 isolates per patient) which were presumptively identified by their brown to black colony pigmentation on anaerobically-incubated enriched Brucella blood agar primary isolation plates containing amoxicillin at 8 μg/ml as amoxicillinresistant, dark-pigmented, gram-negative, anaerobic rods. Each of the amoxicillinresistant, dark-pigmented clinical isolates were subjected to MALDI-TOF mass spectrometry analysis using a bench top mass spectrometer, Bruker FlexControl 3.0 software, and MALDI Biotyper 3.1 software (Bruker Daltonics, Billerica, MA, USA), which contains mass spectra for dark-pigmented, gram-negative, anaerobic rods in its reference library of bacterial protein profiles. A MALDI Biotyper log score of ≥ 1.7 was required for reliable taxonomic classification of the clinical isolates. Results: Only 4 (16.7%) of the chronic periodontitis patients yielded two different dark-pigmented species on amoxicillin-supplemented primary isolation plates, while all other study patients had only one amoxicillin-resistant, dark-pigmented species. Amoxicillin-resistant strains of Prevotella nigrescens were identified in 11 (45.8%) patients, Prevotella intermedia in 8 (33.3%) patients, Prevotella denticola and/or Prevotella species in 3 (12.5%) patients, Porphyromonas gingivalis in 2 (8.3%) patients, and Prevotella melaninogenica in one (4.2%) patient. 50 (70.4%) of the amoxicillinresistant clinical isolates exhibited MALDI Biotyper log scores of ≥ 1.7, the threshold for reliable taxonomic classification, whereas 21 (29.6%) had log scores < 1.7, indicating a less reliable species identification. Conclusions: These findings demonstrate that a range of specific amoxicillinresistant bacterial species comprise cultivable isolates of dark-pigmented, gram-negative, anaerobic rods in the human chronic periodontitis subgingival microbiota. P. nigrescens was the most frequently isolated amoxicillin-resistant, dark-pigmented subgingival bacterial species, followed by P. intermedia. Two study patients surprisingly revealed amoxicillin-resistant strains of P. gingivalis. The occurrence of amoxicillin-resistant, dark-pigmented rods in chronic periodontitis lesions may complicate selection, and markedly reduce the potential effectiveness, of systemic periodontal antimicrobial therapies involving beta-lactam antibiotics.<br>Temple University--Theses
24
Neves, Aline Aparecida Camargo das. "Análises genômicas de Methylobacterium mesophilicum SR1.6/6 com ênfase na interação com a planta hospedeira." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-04122015-174951/.
Testo completoAbstract (sommario):
Bactérias do gênero Methylobacterium são encontradas em associação com espécies vegetais, onde são capazes de promover o crescimento, aumentar a atividade fotossintética e reduzir o ataque de patógenos ao hospedeiro. Além de conferir estas vantagens para a planta hospedeira, estas bactérias podem também produzir biopolímeros (PHA e PHB). Desta forma, o objetivo deste trabalho foi anotar o genoma de Methylobacterium mesophilicum SR1.6/6 e avaliar o seu transcriptoma em estágios iniciais de interação com Citrus sinensis. A análise do genoma mostrou que SR1.6/6 pode produzir auxina, reduzir o estresse da planta alterando os níveis de etileno, apresenta sistema de monitoramento de populacional pelo sistema quorum sensing (QS) e um metabolismo metilotrófico completo. A análise do transcriptoma evidenciou que os exsudatos radiculares de C. sinensis induzem a expressão de genes de resposta ao estresse oxidativo, seguido da indução de genes de adesão e biofilme durante a colonização da planta hospedeira. A interação entre M. mesophilicum SR1.6/6 e a planta hospedeira envolve mecanismos de reconhecimento e adaptação ao estresse, antes mesmo de ocorrer o primeiro contato físico entre a célula bacteriana e a planta hospedeira, seguido da indução de genes de biofilme bacteriano. Além disso, foi estudada uma metodologia para a realização de mutações genéticas em Methylobacterium spp. que permitirá a obtenção de mutantes relacionados com a interação com a planta.<br>Methylobacterium genus are found in association with plant species, where they are able to promote plant growth, increase the photosynthetic activity and reduce the incidence of pathogens to the host. In addition to providing these benefits to the host plant, these bacteria can also produce biopolymers (PHA and PHB). Thus, the aim was to annotate the genome of Methylobacterium mesophilicum SR1.6 / 6 and assess their transcriptome in the early stages of interaction with Citrus sinensis. Genome analysis showed that SR1.6 / 6 can produce auxin, reduce plant stress by altering ethylene levels, presents population monitoring system (QS) and a complete methylotrophic metabolism. The transcriptomic analysis showed that C. sinensis exudates induce the expression of genes related to oxidative stress followed by induction of adhesion and biofilm genes during colonization of the host plant. The interaction between M. mesophilicum SR1.6 / 6 and the host plant involves recognition mechanisms and adaptation to stress, even before the first physical contact occurs between the bacterial cell and the host plant, followed by the induction of bacterial biofilm genes. Furthermore, a method has been studied for carrying genetic mutations in Methylobacterium spp. allowing the obtaining of mutants related to interaction with the plant.
25
Hu, Qinghui. "Isolation and structural and spectral characterization of the light-harvesting pigment-protein complexes and their polypeptides from the purple bacterium Rhodocyclus tenuis /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10846.
Testo completo
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Lehmann, Rainer Patrick. "Studies on the structure and function of the bacteriochlorophyll C antenna complex of the chlorosomes from the phototrophic bacterium Chloroflexus aurantiacus : the pigment-binding function of the 5.7 kDa polypeptide /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10687.
Testo completo
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Fuentes, Quispe Ivette Alejandra. "Caracterización fisiológica y genómica de dos cepas nativas del género Shewanella con potencial biodegradador de colorantes azoicos." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2019. https://hdl.handle.net/20.500.12672/10415.
Testo completoAbstract (sommario):
La industria textil libera al ambiente grandes cantidades de aguas residuales que, entre otros varios contaminantes, contienen colorantes azo en su composición, los cuales son compuestos tóxicos, carcinogénicos y mutagénicos que afectan negativamente la vida acuática y la calidad del agua. El presente estudio tuvo por objetivo caracterizar a nivel fisiológico y genómico cepas nativas con potencial de degradación de colorantes azo obtenidas de un efluente de industria textil de Lima, Perú. Se aplicó el método de la microplaca a doce aislados bacterianos para su selección en base a su respuesta positiva a la decoloración de tres colorantes azo: Azul directo 71, Rojo remazol RGB y Amarillo Oro Remazol RGB. La actividad decolorante de las cepas seleccionadas fue evaluada mediante espectrofotometría UV-Visible en medio ZZ con el colorante respectivo a 100 ppm y en condiciones de microaerofilia durante 24 horas. El secuenciamiento de los genomas se realizó utilizando la tecnología HiSeq 2500 de Illumina, el ensamblaje de novo con el software SPAdes, la extensión de los contigs y reparación de gaps a través de los programas ABACAS e IMAGE y la anotación con Prokka. Las dos cepas con mejor eficiencia de degradación correspondieron a Shewanella sp. LC-2 y Shewanella sp. LC-6, ambas identificadas mediante análisis filogenómico resultando muy cercanas al grupo filogenético de Shewanella sp. FDAARGOS_354. Las cepas mostraron una actividad decolorante frente a Azul Directo 71, Rojo Remazol y Amarillo Remazol con porcentajes de 94.42, 94.79, 91.67 para Shewanella sp. LC-2 y 94.37, 94.92, 83.24 para Shewanella sp. LC-6 a las 24 h. Asimismo, los genomas de Shewanella sp. LC-2 y LC-6 revelaron la presencia de genes que codifican azorreductasas dependientes de NADH, peroxidasas decoloradoras de tinte (DyPs), genes implicados en la desaminación, asimilación de sulfatos, reducción de nitratos y metales pesados, como también en la degradación de benzoatos, catecol y gentisato. Se concluye que las cepas Shewanella LC-2 y LC-6 tienen una actividad metabólica eficaz para la decoloración de Azul directo 71, Rojo remazol RGB y Amarillo Oro Remazol RGB, presentan versatilidad catabólica y son de potencial aplicación en la biorremediación de aguas residuales textiles.<br>Universidad Nacional Mayor de San Marcos (Lima). Vicerrectorado de Investigación y Posgrado<br>Perú. Ministerio de la Producción. Programa Nacional de Innovación para la Competitividad y Productividad (Innóvate Perú). Fondo para la Innovación, la Ciencia y la Tecnología (FINCyT)<br>Tesis
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COSTA, Marília Teixeira. "Avaliação microbiana das manchas dentárias extrínsecas negras em pacientes submetidos a tratamento ortodôntico." Universidade Federal de Goiás, 2011. http://repositorio.bc.ufg.br/tede/handle/tde/1513.
Testo completoAbstract (sommario):
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Previous issue date: 2011-07-04<br>Black extrinsic tooth stains appear on the smooth surfaces of teeth, parallel to the marginal gum and are considered a specific form of biofilm due to the high content of calcium, phosphate and insoluble iron salt. This study evaluated the profile of bacterial biofilms in patients with black extrinsic tooth stain with or without fixed metal braces installed. Four bacteria were investigated using conventional multiplex PCR (Polymerase Chain Reaction), black-pigmented bacteria: Prevotella nigrescens and Prevotella intermedia and non pigmented bacteria: Streptococcus mutans and Actinomyces spp. The study enrolled 52 patients, 25 females and 27 males. They were divided into two groups: Group I: 26 patients with black extrinsic tooth stains and Group II: 26 without stains.
Twenty patients had fixed orthodontic brackets of stainless steel. The results showed that in both group (I and II) 61.5% of patients had at least one of the
bacteria investigated. The P. nigrescens was the most frequently bacteria detected [Group I (30.7%) and Group II (46.1%)], P. intermedia was detected in
3.8% in Group I and 11.5% in Group II. The non pigmented bacteria were found
in similar rates in Groups I and II, 19.2% vs 11.5% for Actinomyces spp and
23.1% vs 30.7% for S. mutans. There were no statistically significant differences
when comparing the frequencies of each bacterium between groups, indicating
that bacterial profiles were similar between patients with or without black
extrinsic stains. When analyzed the frequencies of bacteria in the biofilm in black
extrinsic tooth stain in patients with braces results indicated that it did not alter
the frequency of bacteria found, however, it was observed that the presence of
fixed orthodontic appliance significantly reduces the associations between
bacteria in the biofilm of black extrinsic stains (p <0.05).<br>As manchas dentárias extrínsecas negras aparecem nas superfícies lisas dos
dentes, paralelas à gengiva marginal, e são consideradas uma forma de
biofilme dentário devido ao grande conteúdo de cálcio, fosfato e sal insolúvel de
ferro. Este estudo foi realizado com o objetivo de avaliar o perfil bacteriano dos
biofilmes dentários de pacientes portadores ou não de manchas dentárias
extrínsecas negras, com ou sem aparelho ortodôntico metálico fixo instalado.
Para isto foi utilizada a técnica de multiplex PCR (Polymerase Chain Reaction)
para investigar a presença das bactérias pigmentadoras de negro: Prevotella
nigrescens e Prevotella intermedia e as bactérias não pigmentadoras de negro:
Streptococcus mutans e Actinomyces spp nos biofilmes. A amostra consistiu de
52 pacientes, 25 do gênero feminino e 27 do gênero masculino. A amostra foi
dividida em dois grupos: Grupo I: 26 pacientes portadores de manchas e Grupo
II: 26 pacientes não portadores de manchas. Do total da amostra, 20 pacientes
estavam sob terapia ortodôntica fixa, utilizando bráquetes de aço inoxidável. Os
resultados mostraram que tanto no grupo I, quanto no grupo II, em 61,5% dos
pacientes foi detectada pelo menos uma das bactérias investigadas. P.
nigrescens foi a bactéria mais frequentemente detectada no Grupo I (30,8%) e
no Grupo II (46,1%), enquanto P. intermedia foi detectada em 3,8% no Grupo I
e 11,5% no Grupo II. As bactérias não pigmentadoras de negro foram
encontradas em frequências similares nos Grupos I e II (19,2% versus 11,5%
para Actinomyces spp e 23,1% versus 30,7% para S. mutans). Não foram
encontradas diferenças estatisticamente significativas quando comparando as
frequências de cada bactéria entre os grupos, indicando que os perfis
bacterianos são similares entre pacientes que apresentam e os que não
apresentam manchas extrínsecas negras. Quando analisadas as frequências
das bactérias nos biofilmes nas manchas dentárias extrínsecas negras dos
pacientes portadores de aparelho ortodôntico, os resultados indicaram que o
aparelho não alterou a frequência das bactérias encontradas, porém, foi
observada redução significante das associações entre as diferentes bactérias
no biofilme das manchas extrínsecas negras (p<0,05).
29
CHEN, LYU-AN, and 陳律安. "Study on Production and Characterization of Red Pigments From The Isolated Bacterial Strains." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/7w7s3h.
Testo completo
30
Jehlička, J., Howell G. M. Edwards, and A. Oren. "Raman spectroscopy of microbial pigments." 2014. http://hdl.handle.net/10454/10464.
Testo completoAbstract (sommario):
No<br>Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions.
31
YU-Li-Do and 杜尤莉. "Effect of cultural methods on production of the bacterial pigment." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/10875517843966984352.
Testo completoAbstract (sommario):
碩士<br>建國科技大學<br>美容科技研究所<br>102<br>Chromobacterium violaceum is a bacterium commonly found in tropical and subtropical regions. C. violaceum produces and secretes a purple color compound named violacein. The purpose of this study is to develop an efficiency method for mass production of violacein as a make-up material. Different experimental conditions, including nutrition mediums, tryptophan, UV irradiation, and co-culturing C. violaceum with other bacteria were tested, and the amounts of vioalcein were measured. The results show that upon ultraviolet radiation, C. violaceum cultured in the M9 medium could produce more violacein molecules. Adding tryptophan into the medium could significantly increase the production of violacein, but also result in increased costs. Co-culturing C. violaceum with bacterial strains belonging to Enterococcus and Bacillus could also increase violacein yields. This co-culturing method might be applied in the mass production of violacein in the future.
32
Maresca, Julia A. "The genetic basis for pigment variation among green sulfur bacteria." 2007. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1876/index.html.
Testo completo
33
Chen, Yen-Chu, and 陳彥竹. "Studies on the red pigment from a Gram (-) bacterium strain No. 25." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/96202660945635910518.
Testo completo
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Gonçalves, S. "Bacterial cellulose as a novel substrate for retinal pigment epithelium cells transplantation in age-related macular degeneration." Doctoral thesis, 2015. http://hdl.handle.net/1822/38486.
Testo completoAbstract (sommario):
Tese de Doutoramento em Engenharia Química e Biológica.<br>Bacterial cellulose (BC) has been increasingly recognized for its great potential in a number of
biomedical applications, due to its unique properties such as high mechanical strength,
biocompatibility and non-toxicity. The feasibility of BC as a novel substrate for retinal pigment
epithelium (RPE) transplantation was addressed in this thesis. BC sheets were produced in static
cultures of Gluconacetobacter xylinus bacteria, sliced into thin films and dried. Two approaches
were adopted to modify the BC surface: acetylation and polysaccharide adsorption using
carboxymethyl-cellulose or chitosan. The first approach decreases the BC hydrophilicity, while the
second increases protein adsorption through incorporation of carboxyl or amine groups. The
modified substrates were characterized according to the relevant properties for the envisaged
application: surface chemistry, wettability, free energy, topography; and bulk properties such as
permeability, dimensional stability, tensile strength and level of endotoxins. Their ability to
promote RPE cell adhesion and proliferation in vitro was also studied using the hTERT-RPE1
immortalized cell line. The impact of an extracellular matrix, the urinary bladder matrix (UBM), in
cell response was studied, as well as the cell morphology using UBM-coated substrates.
Acetylation decreased substrate swelling and the amount of endotoxins present. All modified BC
substrates were porous and permeable to 35 and 300 kDa polysaccharide solutes. The moderate
hydrophilic surface of acetylated BC (ABC) substrates was maintained after UBM coating. Surface
modification greatly enhanced the adhesion and proliferation of hTERT-RPE1 cells in BC.
Although similar proliferation rates were observed among the modified BC substrates, the ABC
with UBM substrate exhibited the closest profile to the control surface (polystyrene). Cells
adhered to UBM-coated ABC express the RPE cell markers: ZO-1 (junction protein) and RPE65
(protein involved in the visual cycle of retinal). HTERT-RPE1 cells cultured in UBM-coated ABC
substrates were also able to develop transepithelial resistance, showing polygonal shape cell
morphology in a monolayer configuration with the development of microvilli. In summary, this
study emphasises the great potential of BC as a substrate for RPE transplantation. However,
studies of RPE cell function in these substrates using primary RPE cells, as well as in vivo assays
to infer the substrates biocompatibility are still required.<br>A celulose bacteriana (CB) tem sido progressivamente reconhecida pelo seu potencial em diversas
aplicações biomédicas devido a propriedades únicas como elevada resistência mecânica,
biocompatibilidade e ausência de toxicidade. Nesta tese é avaliado o potencial da CB como substrato
para o transplante do epitélio pigmentar da retina (EPR). A CB foi produzida em culturas estáticas da
bactéria Gluconacetobacter xylinus, fatiada em filmes finos e desidratada. Foram adoptados dois tipos
de modificação de superfície da CB: acetilação e adsorção de quitosano ou carboximetil-celulose. A
primeira modificação reduz a elevada hidrofilicidade da CB, enquanto a segunda aumenta a adsorção
proteica pela incorporação de grupos amina ou carboxilo. Os substratos modificados foram
caracterizados de acordo com as propriedades relevantes para a aplicação pretendida: composição
química, grau de hidrofilicidade, energia livre e topografia da superfície; assim como permeabilidade,
nível de endotoxinas, estabilidade dimensional e propriedades mecânicas. De seguida foi avaliada a
capacidade das células do EPR aderirem e proliferarem nos substratos, utilizando a linha celular
imortalizada hTERT-RPE1. O impacto na resposta celular de uma matriz extracelular, a matriz da bexiga
(MB), e a morfologia de células do EPR foram estudados em substratos com MB.
A acetilação diminuiu o nível de inchamento e de endotoxinas do material. Todos os substratos
desenvolvidos demonstraram ser porosos e permeáveis a polissacáridos de 35 e 300 kDa. A
hidrofilicidade moderada da superfície da CB acetilada (CBA) manteve-se após adsorção da MB. A
modificação da BC aumentou significativamente a adesão e proliferação das células hTERT-RPE1.
Embora as taxas de proliferação celular tenham sido semelhantes para os vários substratos de CB
modificada, a CBA com MB revelou o perfil mais similar ao controlo (plástico). Verificou-se que as
células aderidas à CBA com MB expressam os marcadores proteicos do EPR: ZO-1 (proteína de
junções intercelulares) e RPE65 (proteína envolvida no ciclo visual de retinal). As células cultivadas em
CBA com MB foram também capazes de desenvolver resistência transepitelial e uma morfologia
poligonal em monocamada com microvilosidades. Em suma, este estudo enfatiza o enorme potencial
da CB como substrato para o transplante do EPR. Contudo ainda será necessário efetuar estudos do
funcionamento das células do EPR nos substratos utilizando para o efeito células primárias, bem como
estudos in vivo que permitam aferir a biocompatibilidade destes substratos.<br>Fundação para a Ciência e Tecnologia SFRH/BD/63578/2009.
35
Tzeng, Sue-Jen, and 曾素真. "Identification and Characterization of Foliar Pantoea agglomerans and Other Yellow-pigmented Bacteria from Taiwan." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/95678644029831733060.
Testo completoAbstract (sommario):
碩士<br>國立中興大學<br>植物病理學系<br>89<br>柒、英文摘要
A total of one hundred and seventy five strains of yellow-pigmented bacteria were isolated from twenty-two crop species and four weed plant species at different localities in Taiwan. Among them, 106 strains were Gram negative, and the other 69 strains were Gram positive. Based on Biolog identification system, 61 strains of Gram negative bacteria were identified as species in Actinobacillus, Burkholderia, Chryseobacterium, Enterobacter, Erwinia, Flavimonas, Haemophilus, Pantoea, Pseudomonas, Sphingomonas, Stenotrophomonas, and Xanthomonas. Thirteen strains of Gram positive bacteria were identified as species in Corynebacterium, Curtobacterium, Kytococcus, Microbacterium, Micrococcus, and Staphylococcus. There were 17 strains of Pantoea agglomerans isolated in this study. Utilization of carbon sources by these 17 strains of P. agglomerans were examined with the Biolog GN2 Microplate. The results revealed that among the 95 carbon sources tested, all these 17 strains could utilize 40 carbon sources; and varied in the utilization of 37 carbon sources; in addition, they all did not utilize the other 18 carbon sources. When DNAs from P. agglomerans strains isolated in this study were used as templates, no specific DNA fragment was amplified by PCR with primer pairs etzⅠL/etzⅠR, which are specific to cytokinin biosynthesis gene (etz) of P. agglomerans pv. gypsophilae. Most strains of P. agglomerans isolated showed inhibitory effect on the growth of phytopathogenic bacteria tested. The relative disease index of bacterial spot on leaves of sweet pepper co-inoculated with cell suspensions of X. axonopodis pv. vesicatoria XVT40 and P. agglomerans Yh93 or Yh95 was significantly lower than that of the control plants on which the plants were inoculated with X. axonopodis pv. vesicatoria XVT40 only.
36
Guimarães, Joana Filipa da Silva Almeida Valadas. "Bio Fermented Colors - Pigmentos de Origem Bacteriana: Uma Alternativa Sustentável no Design de Moda e Têxtil." Master's thesis, 2017. http://hdl.handle.net/10400.6/6719.
Testo completoAbstract (sommario):
No momento em que vivemos, torna-se indispensável um acompanhamento constante sobre os perigos que colocamos ao nosso planeta e o impacto ambiental que, cada avanço tecnológico tem sobre a forma como moldamos a vida de gerações futuras. É necessário saber gerir de forma objetiva e criteriosa, as mais recentes descobertas em diversos campos, enriquecendo a nossa qualidade de vida sem, no entanto, prejudicar a sustentabilidade dos ecossistemas que nos rodeiam.
Deste modo, torna-se imprescindível criar soluções alternativas e viáveis para problemas que surgem pela contínua utilização de materiais derivados de petróleo, não-renováveis e de cariz sintético. Não se trata apenas, de criar soluções alternativas prolongando a durabilidade de matérias, cada vez mais escassas e finitas, mas encontrar um caminho sustentável que nos permita garantir a conservação ambiental, prevenção de problemas de saúde, com igual qualidade e custo inferior, dos meios de proveniência não-renováveis, a que estamos habituados a recorrer.
Existe uma crescente consciencialização pública, sobre a utilização de produtos benignos e não nocivos, tanto para o meio ambiente como para a saúde humana. São cada vez mais, os adeptos e entusiastas de diversas áreas que se interessam e desenvolvem tecnologias, a partir de compostos naturais, que irão servir diferentes aplicações.
No âmbito do setor têxtil, a contínua exploração na opção de materiais de origem renovável, tem vindo a ser cada vez mais significativa. A investigação de novas fontes, de corantes naturais, está a tornar-se numa vertente de grande investimento. Um dos modos de atuação está, intimamente, ligado à utilização de microrganismos na produção de pigmentos naturais, assunto que tem vindo a despertar grande interesse por diversos investigadores. Deste modo, a dissertação recaiu sobre este tema, visando uma perspetiva exploratória e adotando a metodologia Tentativa-Erro.
O objetivo deste projeto será delinear, novos processos de introdução de cor, em diversos materiais têxteis, tendo como ponto de partida a fermentação de vários microrganismos, pensados como corantes naturais alternativos, capazes de garantir o mesmo tipo de qualidade e características dos corantes sintéticos.
O uso de várias bactérias para produzir bio-pigmentos já é amplamente descrito na literatura, mas existem algumas questões ainda por explorar. Requereu experimentação e aperfeiçoamento de novas técnicas, que serão apresentadas, como soluções promissoras para aplicações futuras. Não obstante, teve-se em consideração a informação recolhida em várias publicações e revisões sobre todos os processos de tingimentos naturais, extração de pigmentos bacterianos, otimizações de processos, meios de fermentação, custos e estratégias de produção, tendo como particular foco a sua utilização na Indústria Têxtil e Design de Moda. Espera-se que esta abordagem inovadora possa abrir novas vias para o desenho de opções renováveis utilizando microrganismos como fonte prioritária, respondendo a questões ambientais, capazes de serem industrializadas, reconhecendo o cumprimento de uma série de parâmetros que, dizem respeito à sustentabilidade do processo produtivo e, garantindo normas de qualidade exigidas pelos consumidores.
A pesquisa sobre a aplicação dos pigmentos de origem bacteriana levou ao desenvolvimento laboratorial necessário, convergindo no projeto de Design Conceptual – Bio Fermented Colors, onde os bio-pigmentos seriam o foco principal para o seu desenvolvimento.<br>In these times we are living in it becomes impossible not to consider the danger we ourselves pose to the planet and the environmental impact each technological advancement may have on future generations. It is much needed to manage in the most rigorous and objective manner the most recent discoveries in every single field, improving our way of life with no, or very little, damage to the ecosystem and its sustainability. It is crucial to come up with real practical solutions to the problems that the continuous dependency on fossil fuels, fossil fuels’ derivatives, non-renewable and synthetic materials are causing. The point is not to make sure we endure the use of these materials through new and alternative solutions, such materials are becoming increasingly scarce and they are indeed finite. What we do need is to find a sustainable way that guarantees the conservation of the environment, health promotion and disease prevention, at a high quality level but at a lower cost than the non-renewable sources, we are used to rely upon. There is a growing public awareness about the use of both safe and environmentally friendly products. There are more and more people interested in developing technology out of natural compounds to be later applied onto several industries. In the textile industry there has been an ongoing quest for renewable materials. A great deal has been invested into research on new sources of natural pigments. Several researchers have been paying special attention to the use of microorganisms to obtain natural pigments which have already become one of the main areas of focus. Hence this dissertation will address that same subject, adopting an investigative approach making use of the trial and error method. The use of bacteria to produce bio-pigments is already extensively described in the literature but there are still issues to be addressed. That will definitely require experimentation and the improvement of new techniques, which can very likely become promising solutions to future applications. The goal of this project is to outline new methods of color application in different textile materials, based on the fermentation process of microorganisms thought out as alternative natural dyes capable of guaranteeing the same quality level and characteristics of the synthetic dyes. Regardless, it will be taken into account the information collected from several publications on natural dye processes, extraction of bacterial pigments, process optimization, types of fermentation, costs as well as production strategies without ever forgetting its application in the textile industry and fashion design. This innovative approach will open up new possibilities to the use of microorganisms as a leading renewable source that tackles environmental questions while also being fit for industrialization, meeting all the requirements for a sustainable production process and the quality demanded by the consumers. Research on the application of bacterial pigments led to the necessary laboratory development, converging in the Conceptual Design project - Bio Fermented Colors, where bio-pigments would be the focus for its development.
37
Shahina, Mariyam, and 瑪麗央. "Characterization of novel pigmented-bacteria and mutagenic impact of ethyl methanesulfonate on polyphasic taxonomic markers." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/jf3n7x.
Testo completoAbstract (sommario):
博士<br>國立中興大學<br>土壤環境科學系所<br>102<br>Bioactive natural products from the marine resources, including microorganisms encompass potential industrial and bio-medical applications. Irrespective of the enormous difficulty in isolating and harvesting marine bacteria, naturally occurring bioactive microbial metabolites are increasingly attractive due to their broad-ranging pharmacological activities, especially those with unique color pigments. However, characterization of bioactive compounds including pigments is quite complicated and thus given least importance so far in polyphasic taxonomy, which on the other hand integrates several kinds of data pertaining phenotypic, genotypic and phylogenetic characteristics during bacterial systematics. Similarly, the cumulative impact of any mutagenic chemical substance on pigment profile as well as other taxonomic markers is poorly studied. In this work, five novel, pigment-producing, Gram-negative, rod-shaped, strictly aerobic and non-spore-forming marine bacterial strains designated CC-AMO-30B, CC-AMZ-30M, CC-AMZ-30N, CC-AMO-30D and CC-AMWY-103B, isolated from coastal surface seawater in Taiwan were subjected to detailed pigment analysis and polyphasic taxonomy. Pigments were analyzed through UV–visible spectrophotometry, high-performance liquid chromatography-diode array detector and liquid chromatographic mass spectrometry. Finally, the impact of mutagenic ethyl methanesulfonate (EMS; doses 0.5% and 1%) on pigment profile and taxonomic markers was assessed with reference to red-pigmented Serratia. Strains CC-AMO-30B, CC-AMZ-30M and CC-AMZ-30N were identified to be Sphingomicrobium species of the family Sphingomonadaceae and named as S. astaxanthinifaciens, S. marinum and S. flavum, respectively. Strains CC-AMO-30D (Robertkochia marina) and CC-AMWY-103B (Luteibaculum oceani) are recognized to be novel genus of the family Flavobacteriaceae and Cryomorphaceae representatives, respectively. Strain CC-AMO-30B synthesized astaxanthin and its putative glycosyl derivatives, strains CC-AMZ-30M, CC-AMZ-30N and CC-AMWY-103B synthesized zeaxanthin and its isomers, whereas strain CC-AMO-30D produced both myxol and zeaxanthin. In addition, five closely related reference strains affiliated to a total of four different genera (Sphingomicrobium, Owenweeksia, Joostella and Galbibacter) were also characterized for their carotenoid profiles. Presently defined doses of EMS proved to be lethal to all novel strains, whereas at similar doses, Serratia strains (EMS-mutants CC-NPM-11>CC-LPM-20>CC-HPM-11) showed extensive heterogeneous alterations in the molecular, structural and biochemical features. The biosynthesis of prodigiosin was blocked completely in CC-NPM-11, where as other strains showed quantitative variation in terms of their prodigiosin profile. EMS-mutation hampered carbohydrate, protein, lipid and nucleic acid metabolism heterogeneously. Biosynthesis of saturated, unsaturated, hydroxyl and cyclo fatty acids were significantly affected. Unidentified aminolipids were most susceptible besides phosphatidylethanolamine, phosphatidylserine and an unidentified phospholipid. An unidentified polyamine, putrescine, cadaverine and spermidine showed significant quantitative variations. In summary, five novel strains and four reference strains of phylogenetically distant taxa were fully characterized for their bioactive pigments that could serve as model organisms for related analyses in the future. Furthermore, current study provided evidence for the lethal impact of EMS on pigmented marine bacterial isolates besides demonstrating susceptibility of pigments and evolutionarily conserved bacterial structural and molecular taxonomic markers for chemical mutation at similar doses in red-pigmented Serratia. While considering the hazardous impact of EMS, it is recommended that preference should be given to the screening and characterization of natural isolates for bioactive pigments instead of opting for strain improvement via chemical mutagenesis.
38
Malina, Tomáš. "Umělá světlosběrná anténa založená na agregaci bakteriochlorofylu c s vybranými pigmenty." Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-415452.
Testo completoAbstract (sommario):
Title: Artificial light-harvesting antenna based on an aggregation of bacteriochlorophyll c with selected pigments Author: Tomáš Malina Department: Department of Chemical Physics and Optics Supervisor of the master thesis: doc. RNDr. Jakub Pšenčík, Ph.D., KCHFO MFF UK Abstract: Solar energy is one of the most important energy sources for all living organisms. The light harvesting takes place in specialised photosynthetic complexes called antennas; they typically contain pigments held by a protein scaffold. Antennas of green bacteria, chlorosomes, are unique in this respect, for they do not need proteins to organise the pigments. The pigments contained in chlorosomes, bacteriochlorophyll (BChl) c, d or e, aggregate spontaneously. This self-aggregation can be used to form an artificial light-harvesting antenna the absorption spectrum of which can be extended by addition of other pigments. Antennas based on aggregation of BChl c with β-carotene and BChl a were prepared by a fast and slow method. The excitation energy transfer efficiency between these pigments was studied. The efficiency of energy transfer from BChl c to BChl a reached up to 95 %, the efficiency of energy transfer from β-carotene to BChl c was lower. An important role of β- carotene in artificial aggregates as well as in chlorosomes is its...
39
Yen-Lin, Ho, and 何彥璘. "Unusual UVA/B Resistance in a Yellow-pigmented Bacterium Isolated from Concrete Wall Surfaces." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/75441101570467280783.
Testo completoAbstract (sommario):
碩士<br>國立清華大學<br>生命科學系<br>90<br>Many concrete wall surfaces that lack nutrients, water, and solar-UV protection represent an extreme environment for life. In this study, sands were sampled from nine different weathered concrete wall surfaces for viable bacterial count. Most counts were around 104 CFU/g or less. A yellow-pigmented bacterium (THY1) that appeared to be a predominant inhabitant in the harsh concrete-surface environment was isolated. An UV irradiator that provides broad-spectrum UV radiation (encompassing UVA, UVB, and UVC) was used to compare UV radiation (UVR) resistance of different bacterial strains. The results of the UVR survival suggested that THY1 possesses novel UVR-inducible UVR resistance that was not observed in Escherichia coli and Micrococcus luteus. SDS-PAGE analysis suggested the presence in THY1 of two~ 30 kDa UVR-inducible proteins.
40
Jhe-GengHsu and 許哲耕. "Investigation on the feeding strategy for the fed-batch fermentation of Halobacterium salinarum and the bacterial pigment production for the scavenging of free radicals." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/4y5uh3.
Testo completoAbstract (sommario):
碩士<br>國立成功大學<br>化學工程學系<br>102<br>Investigation on the feeding strategy for the fed-batch fermentation of Halobacterium salinarum and the bacterial pigment production for the scavenging of free radicals
Author: Jhe- Geng Hsu
Advisor: Mei- Jywan Syu
Department of Chemistry engineering, National Cheng Kung University
SUMMARY
Halobacterium salinarum is an ancient Halobacteriaceae which is able to grow at a high salt environment. It can secrete bacterial pigments which is quite potential with antioxidant application. The purpose of this study is to investigate a efficient way to culture H. salinarum. First, I culture H. salinarum in batch system to make sure which temperature and medium composition can let H. salinarum grows best. Then, I culture H. salinarum in fed-batch system with condition which makes H. salinarum grows best and investigate the best feeding way. In order to have a better H. salinarum saturated cell density, the culturing was set at 37 oC with 0.1 g/L glucose, 0.5 g/L Na-glutamate, 3 g/L Na3-citrite, 7.5 g/L casamino acid, 3 g/L yeast extract, and 200 g/L sodium chloride in medium. H. salinarum grows well during the initial volume test of 1 L with the above conditions by feeding medium containing 0.1 g/L glucose, 0.5 g/L Na-glutamate, and 200 g/L sodium chloride. And so does the free radical scavenging test of the pigment extracted from this kind of culture.
Keywords: Halobacterium salinarum, fed-batch fermentation, free radical scavenging, antioxidant
INTRODUCTION
Halobacterium salinarum is an ancient Halobacteriaceae which is able to grow at a high salt environment. H. salinarum can secrete bacterial pigments with antioxidant function. Many reactions in daily life, like biological aging and food spoilage, are inseparable from oxidation. Therefore, it is quite potential to extract the secreted orange pigment as antioxidants from H. salinarum fermentation.
H. salinarum is a rod shape halophilic archaea. It needs at least 1.5 M sodium chloride for culturing H. salinarum and the optimal sodium chloride concentration is 2.0 M ~5.2 M.
The result of H. salinarum culturing and the quality of pigments H. salinarum secreted may be influence by many conditions such as temperature, light, salt concentration, and organic nutrient concentration. This study cultures H. salinarum and changes culturing temperature, salt concentration, and organic nutrient concentration to make sure which condition can let H. salinarum grows best and secretes pigment which has highest free radical scavenging effect.
MATERIALS AND METHODS
The strains of the extremophile microorganisms H. salinarum was bought from bioresource collection and research center (BCRC), Hsinchu, Taiwan. The culture medium contained sodium chloride, magnesium sulfate, potassium chloride, sodium citrate, yeast extract, casamino acid, Iron(II) chloride, Manganese chloride and Na-glutamate.
The pigments were extracted from H. salinarum by methol: acetone (2:7) and used in free radical scavenging activity test. The pigment was measured by 1, 1-diphenyl-2-picryl-hydrazil (DPPH), solution of DPPH (0.3 mM) in methanol was prepared. 0.75 mL of pigment solution was added to 0.3 mL DPPH solution. he mixture was shaken vigorously and stand at room temperature for 30 min. Then the absorbance was measured at 517 nm by using UV-Visible spectrophotometer. The DPPH scavenging effect was calculated by equation:
DPPH scavenging effect (%) = ((A_0-A))/A_0 ×100%
RESULTS AND DISCUSSION
The effective methods of cultivating H. salinarum were investigated in this study. The first step is to explore the effect of a variety of medium ingredients and the incubation temperature on its batch culture, trying to sum up a relatively good fermentation environment for the further fed-batch experiments. They are to seek a better H. salinarum saturation concentration for the free radical scavenging test, which 2,2'-diphenyl-1- picrylhydrazyl radical (DPPH •) provides a source of free radicals, by its secreted pigment. The result of H. salinarum culture and affect by all conditions are listed in table 1.
Table 1. Results of culturing H. salinarum with different condition
high concentration medium concentration low concentration
yeast extract 5 g/L grows better
(3 g/L)
casamino acid grows better
(7.5 g/L) 5 g/L no obvious change
(2 g/L)
sodium citrate no obvious change
(5 g/L) 3 g/L no obvious change
(1 g/L)
Na-glutamate grows worse
(3 g/L) 1 g/L grows better
(0.5 g/L)
glucose pigment changed
(1.0 g/L) pigment changed
(0.5 g/L) initial grow rate increase
(0.1 g/L )
sodium chloride 250 g/L grows better
(200 g/L) grows worse
(100g/L )
In order to have a better H. salinarum saturated cell density, the culturing was set at 37 oC with 0.1 g/L glucose, 0.5 g/L Na-glutamate, 3 g/L Na3-citrite, 7.5 g/L casamino acid, 3 g/L yeast extract, and 200 g/L sodium chloride in medium. H. salinarum grows well during the initial volume test of 1 L with the above conditions by feeding medium containing 0.1 g/L glucose, 0.5 g/L Na-glutamate, and 200 g/L sodium chloride. And so does the free radical scavenging test of the pigment extracted from this kind of culture.
After set best batch culture condition, this study use this condition to culture H. salinarum by fed-batch culture and try different feeding way to expect the increase of H. salinarum broth saturation concentration and free radical scavenging effect of the pigment which it secrets.
The result of fed-batch culture shows that H. salinarum can grows better when the culture is starting from initial volume 1 L and stop feeding 24 hour for each feeding 12 hour.
CONCLUSION
H. salinarum grows best in batch culture when the medium composed with 0.1 g/L glucose, 0.5 g/L Na-glutamate, 3 g/L Na3-citrite, 7.5 g/L casamino acid, 3 g/L yeast extract, and 200 g/L sodium chloride.
When culture H. salinarum in fed-batch system with above condition, the better way to let H. salinarum grows better is starting from initial volume 1 L and stop feeding 24 hour for each feeding 12 hour.
41
Gouveia, André Alexandre Grangeia. "Evaluation of the antimicrobial activity from Cerâmica Cave (Portugal) bactéria : the case study of Cupriavidus sp." Master's thesis, 2018. http://hdl.handle.net/10773/25363.
Testo completoAbstract (sommario):
Presently, the increasing number of multidrug resistant pathogens continues
to be one of the major issues to be tackled by the scientific community. This is
aggravated by the inability to find antibiotics with new chemical structures and/or
modes of action. Therefore, the search for novel metabolites has expanded to
the prospection of bacterial drug producer’s strains in extreme environments
such as caves. Caves differ from surface environments in some of their core
aspects, creating an extreme and unfavourable environment for microorganisms.
The absence of light, high humidity and typical lack of nutrient input creates
oligotrophic niches throughout the cave, with high potential for harbouring unique
and unexplored microbial populations. Caves represent, thereby, a reservoir of
unknown bacterial diversity potentially with antibiotic producing organisms.
Additionally, few caves have been explored with the specific focus of finding
these microorganisms. Taking this into consideration, this work focused on the
antimicrobial activity of bacterial strains isolated from cave systems. The specific
objectives of this work were: i) to review the methods used in the isolation of drug
producer strains as well as in the evaluation of in vitro antibacterial activity ii) to
identify and screen for antimicrobial activity bacterial strains isolated from
Cerâmica Cave, Portugal; iii) to modulate the production of antimicrobial
compounds and pigments by isolate CC166 (Cupriavidus sp.) and assess their
bioactivity.
An extensive review was made leading to the conclusion that caves may be
one of the next most promising niches for novel drug producer bacterial strains.
Among the isolation methods employed, the use of supplements, a wide variety
of culture media and pre-treatments has been successfully applied in the
isolation of drug producer strains. Based on the literature, the disk diffusion
method and the agar well diffusion assay have been successfully employed on
the screening for drug producer strains.
Through the tackling of the second objective, antibiotic producer bacteria
belonging to several genera were revealed. These included Streptomyces,
Cupriavidus, Bacillus and Paenibacillus. Regarding the third objective, the
employment of several culture media revealed remarkable patterns in the
antimicrobial activity as well as in the modulation of pigments by Cupriavidus sp.
CC166. Notably, Cupriavidus sp. CC166 was able to inhibit all pathogenic
bacteria used as test agents in this work.<br>Atualmente, o contínuo aumento de organismos patogénicos
multirresistentes é uma das maiores problemáticas que a comunidade científica
enfrenta. Isto é acentuado pela incapacidade de encontrar antibióticos com
novas estruturas químicas e/ou modos de ação. Por este motivo, a procura por
novos metabolitos tem vindo a expandir-se para a prospeção de novas estirpes
bacterianas produtoras de antibióticos em ambientes extremos, tais como
grutas. Os ambientes cavernícolas diferem dos de superfície em alguns aspetos
chave, sendo responsáveis por criar um ambiente extremo e menos favorável
para os microrganismos. A ausência de luz, a elevada humidade e a típica falta
de nutrientes gera nichos oligotróficos, ao longo da gruta, com elevado potencial
para possuir populações microbianas únicas e não exploradas. Por este motivo,
estes ambientes representam um reservatório desconhecido de diversidade
bacteriana, potencialmente com organismos produtores de antibióticos.
Adicionalmente, poucas grutas foram exploradas com o foco específico de
encontrar estes microrganismos. Por este motivo, este trabalho focou-se na
atividade antimicrobiana de estipes bacterianas isoladas a partir de sistemas
cavernícolas. Os objetivos específicos deste trabalho foram: i) a revisão dos
métodos usados na obtenção de estirpes com atividade bacteriana, assim como
nos métodos usados na avaliação das atividades antibacterianas; ii) a
identificação e avaliação de atividade antimicrobiana de estipes bacterianas
isoladas a partir da Gruta da Cerâmica, Portugal; iii) modular a produção de
compostos antimicrobianos e pigmentos pelo isolado CC166 (Cupriavidus sp.)
assim como avaliar as suas bioatividades.
Foi realizada uma extensa revisão bibliográfica, que resultou na conclusão
de que os ambientes cavernícolas podem ser um dos próximos nichos mais
promissores para a descoberta de estirpes bacterianas produtoras de novos
metabolitos. Entre os métodos de isolamento empregues, o uso de suplementos,
de uma grande variedade de meios de cultura e de pré-tratamentos, têm sido
aplicados com sucesso no isolamento de estirpes produtoras de antibióticos.
Com base na literatura, os métodos mais aplicados na avaliação da atividade
antimicrobiana das estirpes bacterianas incluem o método disco-difusão e o
método de difusão em ágar por poço.
Através da realização do segundo objetivo, várias bactérias produtoras de
antibióticos pertencentes a diversos géneros foram reveladas. Estes incluíram
os géneros Streptomyces, Cupriavidus, Bacillus e Paenibacillus. Relativamente
ao terceiro objetivo, o uso de vários meios de cultura revelou padrões de
atividade antimicrobiana notáveis, assim como de modulação de pigmentação
por Cupriavidus sp. CC166. Notavelmente, Cupriavidus sp. CC166 demonstrou
a capacidade de inibir todas as bactérias patogénicas testadas neste trabalho.<br>Mestrado em Microbiologia
42
陳冠先. "A Study on Sex Hormones in Gingival Crevicular Fluid and Black Pigmented Bacteria in Subgingival Plaque of Pregnant Women." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/53678181023601981524.
Testo completoAbstract (sommario):
碩士<br>高雄醫學大學<br>牙醫學研究所<br>82<br>Gingivitis is one of the most common oral diseases, which is caused by dental plaque and by the factors produced/released from it. The black pigmented bacteria in subgingival dental plaque is thought to be the pathogens of the gingivitis. Prevotella intermedia and Porphylomonas gingivalis have been shown to be closely associated with human gingivitis. These two kinds of black pigmented bacteria can use female sex hormones such as progesterone or estradiol as a source of nutrients. In pregnant women, the concentrations of progesterone and estradiol are markely increased in serum and both of them are accumulated and found in the gingival tissue. The purpose of this study was to test levels of female sex hormones in gingival crevicular fluid and to observe the relationship between hormones and black pigmented bacteria in subgingival plaque. The results showed that the level of progesterone found in the gingival crevicular fluid of pregnant women was markedly higher than that of women in postpartum stage. The percentage of black pigmented bacteria in subgingival plaque were also higher than that in postpartum stage, and both results were statistically significant. Percentage of black pigmented bacteria was positively correlated with both the progesterone level, pregnancy and the severity of the gingivitis. Severity of the gingivitis was positively correlated with both the plaque index and the percentage of black pigmented bacteria in subgingival plaque.
43
Li, Yu-Wen, and 李玉雯. "Purification, Cloning, and Characterization of an Amine Oxidoreductase from the Purple Pigmented Marine Bacterium, Pseudoalteromonas sp. MA C1-2." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/08260641077688824642.
Testo completoAbstract (sommario):
碩士<br>國立高雄海洋科技大學<br>海洋生物技術研究所<br>101<br>The marine purple pigmented bacterium Pseudoalteromonas sp. MA C1-2 (MA C1-2) isolated from corals has previously been shown to secret two antibacterial metabolites, one having been shown to be the purple pigment, violacein, the other hydrogen peroxide. The current study aimed to identify the source of the hydrogen peroxide. Through a multi-faceted approach involving ammonium sulfate precipitation, anion exchange chromatography, SDS PAGE, and tandem MS analysis, the source of the hydrogen peroxide was narrowed down to be a amine oxidoreductase enzyme. To verify this finding, a strategy combining degenerate PCR and gene walking were employed to obtain a gene encoding the amine oxidoreductase enzyme from MA C1-2 genome, which we named the PAO gene (Pseudoalteromonas amine oxidoreductase). The cell lysate of the BL21(DE3) stain expressing the gene showed strong positive results in the H2O2 indicator plate, while the control bacterial strain gave only negative results. Finally, the purified enzyme was further confirmed to display strong H2O2-generating activity. Together, the results demonstrate that MA C1-2 generates hydrogen peroxide through the activity of the PAO gene, which could be an effective anti-fouling mechanism.
44
Aires, Vanessa Raquel Pinto. "Pigmentação negra em odontopediatria: revisão narrativa da literatura." Master's thesis, 2019. http://hdl.handle.net/10284/9094.
Testo completoAbstract (sommario):
Introdução: As pigmentações negras, um tipo de pigmentação extrínseca, são muito comummente detetadas em pacientes na consulta de medicina dentária. Estas manchas negras aderidas, apesar de serem benignas, causam desconforto aos pacientes por serem inestéticas.
Nesta revisão bibliográfica serão abordadas as principais causas do aparecimento destas manchas e também os seus possíveis tratamentos.
Objetivos: O objetivo do presente trabalho foi pesquisar a causa das pigmentações negras e verificar a relação que estas têm com a higiene oral, a cárie dentária, a idade do paciente e verificar se há algum tratamento eficaz para a resolução destas manchas.
Conclusão: Com a realização da presente revisão bibliográfica conclui-se que a principal causa das manchas negras são as bactérias cromogénicas e que são consideradas um fator protetor de cárie. Até ao momento não foi encontrado nenhum tratamento que iniba o reaparecimento destas manchas negras.<br>Introduction: Black pigmentations, a type of extrinsic pigmentation, are very commonly detected in patients at the dental appointment. These adherent black spots, although benign, cause discomfort to patients because they are unsightly. This literature review will address the main causes of the appearance of these spots and their possible treatments.
Objectives: The aim of the present study was to investigate the cause of black pigmentations and to verify their relationship with oral hygiene, dental caries, the patient's age and to verify if there is any effective treatment to solve these stains.
Conclusion: With the present review we conclude that the main cause of black spots are chromogenic bacteria and are considered a protective factor of caries. So far no treatment has been found that inhibits the reappearance of these black spots.