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Auswahl der wissenschaftlichen Literatur zum Thema „Ruminococcus“
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Zeitschriftenartikel zum Thema "Ruminococcus"
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Chan, W. W., und B. A. Dehority. „Production of Ruminococcus flavefaciens growth inhibitor(s) by Ruminococcus albus“. Animal Feed Science and Technology 77, Nr. 1-2 (Februar 1999): 61–71. http://dx.doi.org/10.1016/s0377-8401(98)00234-x.
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Klieve, Athol V., Melvin T. Yokoyama, Robert J. Forster, Diane Ouwerkerk, Peter A. Bain und Erin L. Mawhinney. „Naturally Occurring DNA Transfer System Associated with Membrane Vesicles in Cellulolytic Ruminococcus spp. of Ruminal Origin“. Applied and Environmental Microbiology 71, Nr. 8 (August 2005): 4248–53. http://dx.doi.org/10.1128/aem.71.8.4248-4253.2005.
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ABSTRACT A genetic transformation system with similarities to those reported for gram-negative bacteria was found to be associated with membrane vesicles of the ruminal cellulolytic genus Ruminococcus. Double-stranded DNA was recovered from the subcellular particulate fraction of all the cellulolytic ruminococci examined. Electron microscopy revealed that the only particles present resembled membrane vesicles. The likelihood that the DNA was associated with membrane vesicles (also known to contain cellulosomes) was further supported by the adherence of the particles associated with the subcellular DNA to cellulose powder added to culture filtrates. The particle-associated DNA comprised a population of linear molecules ranging in size from <20 kb to 49 kb (Ruminococcus sp. strain YE73) and from 23 kb to 90 kb (Ruminococcus albus AR67). Particle-associated DNA from R. albus AR67 represented DNA derived from genomic DNA of the host bacterium having an almost identical HindIII digestion pattern and an identical 16S rRNA gene. Paradoxically, particle-associated DNA was refractory to digestion with EcoRI, while the genomic DNA was susceptible to extensive digestion, suggesting that there is differential restriction modification of genomic DNA and DNA exported from the cell. Transformation using the vesicle-containing fraction of culture supernatant of Ruminococcus sp. strain YE71 was able to restore the ability to degrade crystalline cellulose to two mutants that were otherwise unable to do so. The ability was heritable and transferred to subsequent generations. It appears that membrane-associated transformation plays a role in lateral gene transfer in complex microbial ecosystems, such as the rumen.
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Livaoğlu, Murat, Gürdal Yilmaz, Servet Kerimoğlu, Kemalettin Aydin und Naci Karacal. „Necrotizing fasciitis with ruminococcus“. Journal of Medical Microbiology 57, Nr. 2 (01.02.2008): 246–48. http://dx.doi.org/10.1099/jmm.0.47453-0.
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Necrotizing fasciitis is a life- and limb-threatening soft tissue infection. Due to its underlying predisposition and rapid progression, treatment should be started quickly using antibiotherapy and surgical intervention. Although necrotizing fasciitis is mainly caused by streptococci and staphylococci, it may also be polymicrobial. Other peptostreptococci have been reported as necrotizing fasciitis agents in the literature, though we encountered no cases of necrotizing fasciitis caused by Ruminococcus productus. Here, we describe a case of necrotizing fasciitis caused by R. productus, a Gram-positive, obligatory anaerobe.
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Marcille, F., A. Gomez, P. Joubert, M. Ladiré, G. Veau, A. Clara, F. Gavini, A. Willems und M. Fons. „Distribution of Genes Encoding the Trypsin-Dependent Lantibiotic Ruminococcin A among Bacteria Isolated from Human Fecal Microbiota“. Applied and Environmental Microbiology 68, Nr. 7 (Juli 2002): 3424–31. http://dx.doi.org/10.1128/aem.68.7.3424-3431.2002.
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ABSTRACT Fourteen bacterial strains capable of producing a trypsin-dependent antimicrobial substance active against Clostridium perfringens were isolated from human fecal samples of various origins (from healthy adults and children, as well as from adults with chronic pouchitis). Identification of these strains showed that they belonged to Ruminococcus gnavus, Clostridium nexile, and Ruminococcus hansenii species or to new operational taxonomic units, all from the Clostridium coccoides phylogenetic group. In hybridization experiments with a probe specific for the structural gene encoding the trypsin-dependent lantibiotic ruminococcin A (RumA) produced by R. gnavus, seven strains gave a positive response. All of them harbored three highly conserved copies of rumA-like genes. The deduced peptide sequence was identical to or showed one amino acid difference from the hypothetical precursor of RumA. Our results indicate that the rumA-like genes have been disseminated among R. gnavus and phylogenetically related strains that can make up a significant part of the human fecal microbiota.
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WILLEMS, A., und M. D. COLLINS. „NOTES: Phylogenetic Analysis of Ruminococcus flavefaciens, the Type Species of the Genus Ruminococcus, Does Not Support the Reclassification of Streptococcus hansenii and Peptostreptococcus productus as Ruminococci“. International Journal of Systematic Bacteriology 45, Nr. 3 (01.07.1995): 572–75. http://dx.doi.org/10.1099/00207713-45-3-572.
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Champion, Kathleen M., Carla T. Helaszek und Bryan A. White. „Analysis of antibiotic susceptibility and extrachromosomal DNA content of Ruminococcus albus and Ruminococcus flavefaciens“. Canadian Journal of Microbiology 34, Nr. 10 (01.10.1988): 1109–15. http://dx.doi.org/10.1139/m88-196.
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Seventeen Ruminococcus albus and Ruminococcus flavefaciens strains have been screened for naturally occurring antibiotic resistance, as determined by zones of inhibition from antibiotic disks. These strains were also examined for extrachromosomal DNA content. All strains screened are resistant to low levels (10–200 μg/mL) of streptomycin. In contrast to the previously reported data, we have found that R. flavefaciens C-94 is now susceptible to both kanamycin and tetracycline. However, R. flavefaciens FD-1 is not susceptible to kanamycin (minimum inhibitory concentration (MIC) = 40 μg/mL). Furthermore, R. albus 8 is resistant to tetracycline (MIC = 40 μg/mL), and erythromycin (MIC = 100 μg/mL). Six freshly isolated strains showed resistance to tetracycline (35–70 μg/mL), and all tetracycline-resistant strains also showed resistance to minocycline. None of these Ruminococcus determinants share homology with the streptococcal tetL, tetM, or tetN determinants. All 17 strains were screened for extrachromosomal DNA content. Nine different techniques for the detection and isolation of extrachromosomal DNA were tested. However, owing to difficulties in demonstrating or isolating plasmid DNA, it has not been possible to determine if these antibiotic resistance genes are plasmid borne. Evidence is presented to suggest that the presence of oxygen may affect the quality of the DNA obtained from Ruminococcus.
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Dabard, J., C. Bridonneau, C. Phillipe, P. Anglade, D. Molle, M. Nardi, M. Ladiré et al. „Ruminococcin A, a New Lantibiotic Produced by aRuminococcus gnavus Strain Isolated from Human Feces“. Applied and Environmental Microbiology 67, Nr. 9 (01.09.2001): 4111–18. http://dx.doi.org/10.1128/aem.67.9.4111-4118.2001.
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ABSTRACT When cultivated in the presence of trypsin, the Ruminococcus gnavus E1 strain, isolated from a human fecal sample, was able to produce an antibacterial substance that accumulated in the supernatant. This substance, called ruminococcin A, was purified to homogeneity by reverse-phase chromatography. It was shown to be a 2,675-Da bacteriocin harboring a lanthionine structure. The utilization of Edman degradation and tandem mass spectrometry techniques, followed by DNA sequencing of part of the structural gene, allowed the identification of 21 amino acid residues. Similarity to other bacteriocins present in sequence libraries strongly suggested that ruminococcin A belonged to class IIA of the lantibiotics. The purified ruminococcin A was active against various pathogenic clostridia and bacteria phylogenetically related to R. gnavus. This is the first report on the characterization of a bacteriocin produced by a strictly anaerobic bacterium from human fecal microbiota.
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Anam, Moh Sofi’ul, Andriyani Astuti, Budi Prasetyo Widyobroto, Gunawan . und Ali Agus. „Effects of Combined Organic Selenium and Zinc Supplementation on In Vitro Ruminal Enzyme Activities and Relative Populations of Several Bacterial Species“. World's Veterinary Journal 14, Nr. 2 (25.06.2024): 178–83. http://dx.doi.org/10.54203/scil.2024.wvj22.
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Selenium (Se) and zinc (Zn) are essential animal microminerals. Combining Se and Zn (Se-Zn) as a feed additive in its influence on rumen fermentation patterns is still very limited, so further investigation is needed. The present study explored the supplementation impact of combined Se-Zn from organic sources on rumen enzyme activity and relative abundance of several bacterial species through an in vitro method. Five treatments, each with six replicates were used in the study. The first group treated without Se and Zn supplementation (T0, control), the second group treated with 0.3 ppm Se + 60 ppm Zn (T1), the third group treated with 0.45 ppm Se + 60 ppm Zn (T2), the fourth group treated with 0.3 ppm Se + 90 ppm Zn (T3), and the fifth group treated with 0.45 ppm Se + 90 ppm Zn (T4). The parameters observed included rumen microbial enzyme activities (carboxyl methyl cellulase, amylase, protease) and the relative abundance of rumen microbes (Ruminococcus sp., Ruminococcus flavefaciens, Ruminococcus albus, Streptococcus sp., Prevotella ruminicola, and Eubacterium ruminantium). Results indicated that carboxyl methyl cellulase (CMC-ase) and amylase activities raised in T2, T3, and T4 in comparison to T1 and T0 treatments. Protease activity and protein enzyme content increased in T2 compared to all treatments. The relative abundance of Ruminococcus sp. and Ruminococcus albus was higher in T2 and T3 compared to T0 treatment. Furthermore, an elevated Ruminococcus flavefaciens was indicated in T2 compared to other treatments. The T2, T3, and T4 led to higher abundances of Eubacterium ruminantium, Prevotella ruminicola, and Ruminococcus albus compared to T0 and T1. It is concluded that organic Se and Zn enhanced the relative abundance of several bacterial species and the activity of enzymes in the rumen; optimal results are recommended when combining 0.45 ppm Se + 60 ppm Zn.
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Chassard,, Christophe, Eve Delmas,, Céline Robert,, Paul A. Lawson und Annick Bernalier-Donadille. „Ruminococcus champanellensis sp. nov., a cellulose-degrading bacterium from human gut microbiota“. International Journal of Systematic and Evolutionary Microbiology 62, Nr. 1 (01.01.2012): 138–43. http://dx.doi.org/10.1099/ijs.0.027375-0.
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A strictly anaerobic, cellulolytic strain, designated 18P13T, was isolated from a human faecal sample. Cells were Gram-positive non-motile cocci. Strain 18P13T was able to degrade microcrystalline cellulose but the utilization of soluble sugars was restricted to cellobiose. Acetate and succinate were the major end products of cellulose and cellobiose fermentation. 16S rRNA gene sequence analysis revealed that the isolate belonged to the genus Ruminococcus of the family Ruminococcaceae. The closest phylogenetic relative was the ruminal cellulolytic strain Ruminococcus flavefaciens ATCC 19208T (<95 % 16S rRNA gene sequence similarity). The DNA G+C content of strain 18P13T was 53.05±0.7 mol%. On the basis of phylogenetic analysis, and morphological and physiological data, strain 18P13T can be differentiated from other members of the genus Ruminococcus with validly published names. The name Ruminococcus champanellensis sp. nov. is proposed, with 18P13T ( = DSM 18848T = JCM 17042T) as the type strain.
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Chen, Junqin, David M. Stevenson und Paul J. Weimer. „Albusin B, a Bacteriocin from the Ruminal Bacterium Ruminococcus albus 7 That Inhibits Growth of Ruminococcus flavefaciens“. Applied and Environmental Microbiology 70, Nr. 5 (Mai 2004): 3167–70. http://dx.doi.org/10.1128/aem.70.5.3167-3170.2004.
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ABSTRACT An ∼32-kDa protein (albusin B) that inhibited growth of Ruminococcus flavefaciens FD-1 was isolated from culture supernatants of Ruminococcus albus 7. Traditional cloning and gene-walking PCR techniques revealed an open reading frame (albB) encoding a protein with a predicted molecular mass of 32,168 Da. A BLAST search revealed two homologs of AlbB from the unfinished genome of R. albus 8 and moderate similarity to LlpA, a recently described 30-kDa bacteriocin from Pseudomonas sp. strain BW11M1.
Dissertationen zum Thema "Ruminococcus"
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Zhang, Jun Xian. „Genetic determination of xylanases in rumen bacterium ruminococcus flavefaciens“. Thesis, University of Aberdeen, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317940.
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The xylanases and xylanase genes in the rumen cellulolytic bacterium Ruminococcus flavefaciens were studied in this thesis. Based on the experiments carried out in this thesis, the following conclusions can be drawn: At least seven multiple xylanases are revealed in R.flavefaciens strain 17 and strain 007, and nine in strain FD-1 by the method used here for activity detection in gels. A im54 kDa constitutive xylanase appears in both strains 17 and 007, but not in FD-1. Straw and xylan are the best substrates for production of most xylanases in R.flavefaciens. Sequencing one of the four xylanase genes isolated from R.flavefaciens 17, xynA, shows a 2862 bp open reading frame initiating from a TTG start codon which is preceded by a Gram-positive Shine-Dalgarno sequence (robosome binding site) of AAAGGAG. The enzyme encoded by xynA (XYLA) is predicted to have 954 amino acids including a probable signal sequence at the amino terminus. XYLA is novel in its structure having two dissimilar catalytic domains (domain A, 248 amino acids; domain C, 332 amino acids) linked by a highly repetitive region (domain B, 374 amino acids) extremely rich in asparagine and glutamine residues. The two catalytic domains can be active independently and act on xylan differently, with domain C producing smaller end products than domain A from oat-spelt xylan. Amino acid sequence comparisons with other enzymes show that domain A and domain C are related to two different families of xylanases, G and F, respectively. Therefore, this thesis provides the first evidence of a bifunctional hemicellulase comprising two different catalytic domains. Antibodies raised separately against domains A and C of XYLA recognize common enzyme bands in Ruminococcus, ranging in apparent molecular mass from 110 kDa to 200 kDa. This tends to confirm that XYLA is produced as a high molecular weight polypeptide in R.flavefaciens, as predicted from the sequence. R.flavefaciens has strong preference of codon usage for several amino acid residues, eg. glutamate (GAG); glutamine (CAG); and lysine (AAG).
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Beaufrère, Marie. „Rôle de la dysbiose du microbiote intestinal et réponse Th17 dans les spondyloarthrites : pathogénie et causalité“. Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASL046.
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Les spondyloarthrites (SpA) sont desrhumatismes inflammatoires chroniques fortementassociés à l'allèle HLA-B27 du complexe majeurd'histocompatibilité de classe I. La preuve du rôlepathogène du HLA-B27 a été apportée par plusieurslignées de rats transgéniques pour le HLA-B27 et lab2 microglobuline humaine (rats B27). Ces rats B27développent spontanément des manifestationscomparables à la SpA humaine. Dans ce modèle, lescellules hématopoïétiques HLA-B27+, leslymphocytes T CD4+ et un microbiote conventionnelsont nécessaires pour développer la maladie. Le rôledu microbiote a également été étayé par la mise enévidence d'une dysbiose intestinale au cours desSpA. Ainsi, une corrélation positive entre l'activitédes SpA et l'abondance de l'espèce bactérienneanaérobie Ruminococcus gnavus dans les selles a étédémontrée.Mon premier objectif de thèse a été de déterminerles mécanismes immunologiques impliqués dans ledéclenchement de la SpA du rat B27 par l'étude despopulations productrices des cytokines clefs de laSpA : l'IL-17 et le TNF. Parallèlement, je me suisintéressée au rôle des souches de R. gnavus aucours de la SpA. Mon premier travail a démontréque les LT CD4+ conventionnels exprimant lerécepteur de chimiokines CCR6 étaient lesprincipales cellules productrices d'IL-17 et de TNFau cours de la SpA et qu'elles étaient capablesd'induire la SpA après transfert à des ratsathymiques nude B27 habituellement protégés. Lesecond axe de ma thèse m'a permis d'isoler dessouches de R. gnavus de patients atteints de SpA etde témoins sains. Des expérimentationscomplémentaires sont nécessaires pour étayer leshypothèses concernant la pathogénicité de R.gnavusSpondyloarthritis (SpA) is a chronicinflammatory rheumatic disease strongly associatedwith the HLA-B27 major histocompatibility complexclass I allele. Proof of the pathogenic role of HLA-B27was provided by lines of transgenic rats for HLA-B27and human β2 microglobulin (B27 rats). These B27rats spontaneously develop manifestationscomparable to human SpA. In this model, HLA-B27+hematopoïetic cells, CD4+ T lymphocytes and aconventional microbiota are required for diseasedevelopment. The role of the microbiota is alsosupported by evidence of intestinal dysbiosis in SpA.A positive correlation between SpA activity and theabundance of the bacterial anaerobic speciesRuminococcus gnavus in stools has beendemonstrated. The first aim of my thesis was todetermine the immunological mechanismsinvolved in triggering SpA by studying thepopulations producing the key SpA cytokines IL-17and TNF in B27 rat. In parallel, I examined thepotential role of R. gnavus strains in SpA. My firstwork demonstrated that conventional CD4+LTexpressing the chemokine receptor CCR6 are themain IL-17 and TNF-producing cells during SpAand are able to induce SpA after transfer to usuallyprotected nude B27 athymic rats. In the secondpart of my thesis, I isolated R. gnavus strains fromSpA patients and healthy controls. Furtherexperiments are required to substantiate thepathogenic hypotheses of R. gnavus in SpA
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Reveneau, Carine. „Biochemical and Genome-Based Analysis of Polysaccharide Degradation by Ruminococcus Albus“. The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1419948721.
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Andrade, Gabriel Belem de. „Estudos estruturais de dockerinas e cohesinas em Ruminococcus flavefaciens e sua aplicação no desenvolvimento de matrizes auto montáveis de proteínas“. Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-14092017-105719/.
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O celulossomo é um complexo multienzimático extracelular utilizado por bactérias anaeróbias para a degradação de biomassa vegetal. Ele é composto por escafoldinas, estruturas alongadas que abrigam diversos módulos cohesina, às quais se ligam dockerinas, seus parceiros de interação específica de alta afinidade, fusionados às enzimas celulolíticas. Os módulos cohesina e dockerina compõem o elemento central da interação entre todos os componentes que integram o celulossomo. Esses módulos são divididos em tipos, de acordo com sua sequência primária. Essa divisão reflete efeitos funcionais distintos, sendo o tipo I responsável pela ligação de enzimas às escafoldinas, enquanto o tipo II medeia a ligação de escafoldinas à célula. O celulossomo de Ruminococcus flavefaciens é o mais complexo conhecido, e na classificação por tipos, suas sequências divergem, formando o tipo III, que foi posteriormente subdividido em 6 grupos para significância funcional. Nesse sistema, o principal responsável pela integração de enzimas ao sistema é a escafoldina primária ScaA, a qual interage com escafoldina adaptadora ScaB. A especificidade dessa ligação - dockerina de ScaA (Rf-DocA) com cohesinas de ScaB (Rf-CohB1-7) - é classificada como único membro do grupo 5, na divisão de grupos que compõem o tipo III. Assim, essa interação é de suma importância para a organização do celulossomo desse organismo, tendo sido estudada por meio de experimentos biofísicos e bioquímicos. Porém a falta de uma estrutura cristalina resolvida desses componentes limita a compreensão que podemos ter sobre a interação. 1-2 Nesse trabalho, apresentamos as estruturas cristalográficas de Rf-DocA, em complexo com a Rf-CohB4, além da estrutura dessa cohesina isolada, e ainda, a Rf-CohB1, e alguns de seus mutantes pontuais. Com isso, esclarecemos aspectos estruturais desses módulos, como a presença de dois sítios funcionais de ligação a cálcio em Rf-DocA. Também é observável pelos modelos gerados, detalhes da ligação entre eles, como os resíduos participantes da interação. Estudos de afinidade entre esses módulos foram conduzidos para a elucidar algumas propriedades da ligação entre esses módulos, de forma que descobrimos que ela ocorre de uma única maneira, e que há um loop na cohesina cuja flexibilidade afeta a afinidade da ligação. Isso sugere um mecanismo de alteração conformacional que regula a ligação à dockerina. Adicionalmente, buscamos o emprego desses módulos em uma aplicação tecnológica, desenhando redes automontáveis de proteínas, visando a construção de um nanomaterial. Essas redes são formadas por características intrínsecas das proteínas que os compõem, sendo o principal fator considerado sua simetria rotacional.3 Nesse sentido, as dockerinas e cohesinas foram utilizadas para ligação entre proteínas de diferentes simetrias. Utilizamos proteínas de simetrias C3, C4 e C6 com fusão a dockerinas, que se conectam às cohesinas fusionadas a proteínas de simetria C2, as quais formam o elemento linear da ligação entre os diferentes módulos. Esse desenho experimental permite a expressão e purificação independentes dos componentes, o que facilita a obtenção das redes, a partir da mistura dos dois componentes. Através de análises preliminares por microscopia eletrônica de transmissão, observamos a formação de filmes bidimensionais extensos e nanotubos com a construção testada.The cellulosome is an intricate multienzyme extracelular complexes evolved by anaerobic bacteria for degradation of cellulosic biomass. It is composed of scaffoldins, elongated structures, which bare numerous cohesin modules, which bind to dockerin modules, their high affinity and specificity partners, borne by cellulolytic enzymes. The cohesin and dockerina modules constitute the central element of the interaction between every component of the cellulosome. These modules are categorized in types, according to their primary sequence. That distribution reflects distinct functions, in which the type I is responsible for integration of enzymes to scaffoldins, while type II mediates anchoring of scaffoldins to the cell wall. The cellulosome of Ruminococcus flavefaciens is the most intricate known to date, which is categorized into a third type of cohesins and dockerins, due to sequence diversion. The type III was further divided into 6 groups to impart functional significance. In that system, the main enzyme integrating component is the primary scaffoldin ScaA, which interacts to the adaptor scaffoldin ScaB. The specificity of this interaction - dockerina of ScaA (Rf-DocA) to ScaB cohesins (Rf-CohB1-7) - is sorted as a single member of group 5, in the subtypes of type III. Thus, this interaction is essential for cellulosome organization, having been studied by biophysical and biochemical experiments. However, the lack of a solved crystalline structure of these components narrows our understanding on this interaction. In the present study, we present the structures of Rf-DocA, complexed to Rf-CohB4, besides the structure of this isolated cohesin, and also Rf-CohB1 and its point mutants. Due to these data, we clarify structural aspects of these modules, such as the occurrence of two functioning calcium binding sites in Rf-DocA. We also identified details of their binding, such as the interacting residues. Through binding affinity studies, we concluded that the interaction between these modules occurs in a single mode, and that there is a loop in the cohesin module whose flexibility has direct effects on the binding affinity to dockerin. Additionally, we sought to utilize these modules in a downstream application, by designing self-assembling arrays of proteins, aiming for the construction of a nanomaterial. These arrays are constructed from the intrinsic properties of its constituent proteins, in which the main factor is rotational symmetry. In this context, dockerina and cohesin modules were used of binding different symmetry proteins. We utilized C3, C4 and C6 point symmetry proteins fused to dockerin modules, which bind to the cohesin modules fused to C2 point symmetry proteins, which establish the linear connection between the distinct components. This experimental design allows for the independent expression and purification of the components, which facilitates the achievement of the arrays, by simple mixture of the two components. Through preliminary analysis by transmission election microscopy, we observed the construction of two-dimensional films and nanotubes.
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Cervera-Tison, Marine. „Investigating the structure, function and regulation of Ruminococcus gnavus E1 alpha-galactosidases“. Thesis, University of East Anglia, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578253.
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Here we report the enzymatic characteristics and regulation of expression for two GH36 a- galactosidases. Agu 1 and Aga,'. li'0111 R. gnavus El. Bioinforrnatics analysis of their respective genetic environment showed a different organisation. Aga 1 having a simple organisation while Aga2 is organised as part nf an ()p~wn. They were heterologously expressed in Escherichia coli. puri tied to homogeneity and their biochemical properties and substrate preferences comparatively analysed. The growth pattern (If the strain in minimum media demonstrates a preference tor complex substratcs (melibiose and raffinose) that require the expression of the a-galactosid.rscs for their utilisation and assimilation. Keywords: a-galactosidase. Ruminococcus gnavus E I. characterisation. transglycosylation. regulation. metabolism
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Torres, Marco Tulio Rincon. „Cellulosome organisation of plant cell wall degrading enzymes in Ruminococcus flavefaciens 17“. Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327013.
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Alatou, Radia. „Caractérisation d'une adhésine de la famille des MSCRAMMs chez ruminococcus gnavus E1“. Aix-Marseille 3, 2010. http://www.theses.fr/2010AIX30014.
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Ruminococcus gnavus E1, une bactérie à Gram positif, anaérobie stricte, isolée du microbiote dominant d'un homme sain. Un ORF d'environ 6kb, nommé radA, a été identifié sur le chromosome de la souche E1, à proximité des clusters génétiques impliqués dans la biosynthèse des bactériocines RumA et RumC qui sont actives contre le pathogène Closthdium perfringens. RadA présente de fortes homologies avec des gènes de Staphylococcus aureus, Bacillus cereus et C. Perfingens codant pour des protéines des adhésines de la famille des MSCRAMMs. La partie du gène radA codant pour les 414 acides aminés situés à l'extrémité N-terminale de la protéine putative mature, sans, a été clonée dans le vecteur pGEXT4, exprimée chez Escherichia coli. Les tests réalisés par la méthode ELISA montrent ce fragment de RadA est impliqué dans l'adhésion au collagène de type I. Afin de localiser plus précisément la région responsable de l'adhésion, le fragment du gène radA codant pour les 218 acides aminés localisés à l'extrémité N-terminale de RadA a été clone dans le vecteur pGEXT4 et exprimé chez E. Coli. La protéine fusion GST-RadA218 présente une adhésion au collagène nettement plus forte que RadA414. Ll a été montré par RT-PCR que le gène radA est fortement exprimé in vivo, quand la souche E1 colonise le tube digestif d'animaux monoxéniques, et peu transcrit in vitro. Les expériences complémentaires montrent que radA est largement disséminé chez différentes souches isolées du microbiote dominant de l'Homme du cluster phylogénétique Clostridium coccoides qui comprend l'espèce R. Gnavus. Les résultats suggère que RadA pourrait jouer un rôle important dans la colonisation de l'écosystème digestifRuminococcus gnavus E1 is a Gram positive strict anaerobic bacterium that was isolated from the dominant faecal microbiota of a healthy adult. A 6kb-long open reading fragment called radA was identified on the E1 chromosome, next to the genetic clusters involved in the biosynthesis of the RumA and RumC bacteriocins which are active against pathogenic Clostridium perfringens. RadA shares a high sequence homology with genes of Staphylococcus aureus, Bacillus cereus and C. Perfingens encoding adhesins of the MSCRAMMs family. The gene fragment coding for the 414 amino acids located at the N-terminus of the mature protein was cloned in the pGEXT4 vector and expressed in Escherichia coli. ELISA-based tests showed that this fragment of RadA is involved in adhesion to type I collagen. To localize more precisely the region responsible for adhesion, the gene fragment coding for the 218 amino acids located at the N-terminus was cloned in the pGEXT4 vector and expressed in E. Coli. The fusion protein GST-RadA218 exhibited a stronger adhesion to collagen than RadA414. RT-PCR experiments demonstrated that the radA gene was strongly expressed in vivo, when the E1 strain colonized the digestive tract of monoxenics animals, while little transcription occured in vitro. Complementary experiences showed that radA was widely spread among various strains isolated of the human dominant microbiota that belonged to the phylogenetic duster Clostridium coccoides that includes the R. Gnavus species. Taken together, these results suggest that RadA could play an important role in the colonization of the digestive ecosystem
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Cervera, Tison Marine. „Investigating the structure, function and regulation of Ruminococcus gnavus E1 [alpha]-galactosidases“. Thesis, Aix-Marseille 3, 2011. http://www.theses.fr/2011AIX30050.
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Ruminococcus gnavus E1 appartient au groupe des Firmicutes, l’un des deux groupes dominants du microbiote intestinal humain. Les a-galactosidases sont des glycosides hydrolase (GH) actives sur des substrats contenant des galactoses liés en a. Elles sont très largement distribuées dans tous les domaines du vivant, bactéries, champignons, plantes et animaux, mais sont absentes du tractus digestif humain. Ces travaux portent sur les caractéristiques enzymatiques et la régulation de l’expression de deux -galactosidase, Aga1 et Aga2, de R. gnavus E1. L’analyse bioinformatique de leur environnement génétique respectif indique une organisation simple pour Aga1 tandis qu’Aga2 est organisée en opéron. Elles ont été exprimées en système hétérologue chez E. coli, purifiées et leurs propriétés biochimiques ainsi que leurs spécificités de substrat ont été analysées. Le profil de croissance de la souche indique une préférence pour des substrats complexes (raffinose et mélbiose) faisant intervenir les a-galactosidase pour leurs utilisations ainsi que leur assimilationRuminococcus gnavus E1 belongs to the Firmicutes, one of the two dominant groups in the human gut microbiota. a-galactosidases are glycoside hydrolases (GH) active on a-galactoside containing substrates. They are widely distributed through all the domains of life: bacteria, fungi, plants, and animals, but are absent from the human gastro-intestinal tract.Here we report the enzymatic characteristics and regulation of expression for two GH36 -galactosidases, Aga1 and Aga2, from R. gnavus E1. Bioinformatics analysis of their respective genetic environment showed a different organisation, Aga1 having a simple organisation while Aga2 is organised as part of an operon. They were heterologously expressed in Escherichia coli, purified to homogeneity and their biochemical properties and substrate preferences comparatively analysed. The growth pattern of the strain in minimum media demonstrates a preference for complex substrates (melibiose and raffinose) that require the expression of the a-galactosidases for their utilisation and assimilation
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Kirby, James. „Multiplicity and organisation of plant cell wall degrading enzymes in Ruminococcus flavefaciens 17“. Thesis, University of Aberdeen, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362230.
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The Gram-positive, strictly anaerobic bacterium, R. flavefaciens, plays an important role in the degradation of plant cell wall polysaccharides in the rumen. There is a paucity of information available, however, regarding the multiplicity and organisation of R. flavefaciens cellulolytic and xylanolytic enzyme systems. A technique involving PCR amplification of DNA with primers designed from conserved sequences, followed by hybridisation of the PCR products to chromosomal DNA, has led to an estimate of xylanase gene multiplicity in R. flavefaciens. The xylanase-specific primers were also useful in the isolation and sequencing of a partial xylanase gene, xynC. Although R. flavefaciens 17 appears to produce a cellulose-binding enzyme-complex, none of the individual enzymes examined was found to bind cellulose in isolation. However, a 210 kDa protein which is present in the complex was shown to bind cellulose after isolation from a renatured SDS-gel. In order to look for genetic evidence for a cellulose-binding mechanism, sequencing of the R. flavefaciens 17 endoglucanase gene, endA, was completed from PCR products. The carboxy-terminus of the predicted endA product consists of a domain which is similar to dockerins found in Clostridium thermocellum polysaccharidases. Homologous domains are also found in the R. flavefaciens xylanases, XynB and XynD. As the C. thermocellum dockerin domains mediate binding to the 210 kDa scaffolding protein in the cellulosome complex, it is likely that the R. flavefaciens domains play a similar role in assembly of a cellulosome-like complex (Lamed and Bayer, 1994). A gene which maps approximately 1.5 kb downstream from endA on the R. flavefaciens 17 chromosome was sequenced and found to be homologous to nifS genes from nitrogen-fixing bacteria (Zheng et al, 1993). The R. flavefaciens NifS product catalyses the production of sulphur from cysteine, and is suspected to partake in the assembly of iron-sulphur clusters. The precise role of NifS is not yet known, but may be related to the degradation of crystalline cellulose.
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Wang, Wenyen. „Molecular analysis of two cellulase genes from Ruminococcus flavefaciens FD-1 and their transcriptional regulation“. Doctoral thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/23584.
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The mesophilic Ruminococcus flavefaciens FD-1 (NCDO 2215) is a Gram-positive obligate anaerobic bacterium. The aim of this thesis was to clone, sequence and analyze a cellodextrinase gene (celA) and a carboxymethylcellulase gene (celE), and study their regulation and induction at the transcriptional level. The sequence of the celA gene from FD-1 was determined and the amino acid sequence of the CelA enzyme (336 amino acid residues) deduced. It showed 40% identity with endoglucanase C of Clostridium thermocellum and 27.4% identity with endoglucanase 3 of Fibrobacter succinogenes. These three enzymes are grouped into subfamily "A3". The ATG start codon of celA is preceded by a GAGG sequence, predicted to be a ribosome binding site. The derived amino acid sequence corresponded to a protein of Mᵣ 38686. SDS-PAGE analysis of in vitro and in vivo translational products showed that CelA has a molecular mass of ca 39 kDa and was secreted into the Escherichia coli periplasmic space. Although CelA has activity on carboxymethylcellulose, further study on the enzyme showed that it degraded cellopentaose and other cellodextrins to predominantly cellobiose. Thus CelA is a cellodextrinase. It also has high activity against p-nitrophenyl-β-D-cellobioside. A gene, expressing a protein with both carboxymethyl cellulase and xylanase activity, was cloned from R. flavefaciens FD-1 using an E. coli/Bacillus subtilis shuttle vector, pEBl. The 3.6 kb DNA insert on the plasmid pWFl, which carried the gene, celE, contained an open reading frame of 963 bp encoding 320 amino acid residues with a caculated Mᵣ of 35937. Homology analysis showed 11.6% identity and 55.3% similarity with the N-terminal catalytic region of the cellulase gene of alkalophilic Bacillus sp. strain 1139. In order to obtain expression in E. coli, the gene had to be transcribed from the lambda Pᵣ promoter. To determine whether cellulase genes of R. flavefaciens FD-1 were regulated at the level of transcription, celA and celE were used as probes against RNA isolated from R. flavefaciens FD-1 grown on cellobiose, cellulose or cellotriose. Transcription of both genes was induced when cellulose was added to cells growing in cellobiose. This induction continued after cellulose depletion and after cell division had ceased. Transcription of both genes was also induced by cellotriose although not to the same extent as by cellulose. This suggests that cellotriose and possibly ether dextrins may act as key inducers to trlgger celA and eels gene expression in R. flavefaciens FD-1.
Buchteile zum Thema "Ruminococcus"
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Cocconcelli, Pier Sandro. „Electroporation of the Anaerobic Rumen Bacteria Ruminococcus albus“. In Electrotransformation of Bacteria, 195–202. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04305-9_24.
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Wood, Thomas M. „Cellulase of Ruminococcus albus“. In Methods in Enzymology, 216–21. Elsevier, 1988. http://dx.doi.org/10.1016/0076-6879(88)60123-6.
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Ohmiya, Kunio, und Shoichi Shimizu. „Cellobiosidase from Ruminococcus albus“. In Methods in Enzymology, 391–98. Elsevier, 1988. http://dx.doi.org/10.1016/0076-6879(88)60144-3.
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Ohmiya, Kunio, und Shoichi Shimizu. „β-Glucosidase from Ruminococcus albus“. In Methods in Enzymology, 408–14. Elsevier, 1988. http://dx.doi.org/10.1016/0076-6879(88)60147-9.
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5
Ohmiya, K., T. Kajino, E. Goto und S. Shimizu. „NUCLEOTIDE SEQUENCE OF THE CELLULASE GENE FROM RUMINOCOCCUS ALBUS AND PROPERTIES OF ITS TRANSLATION PRODUCT“. In Biotechnology in Pulp and Paper Manufacture, 567–73. Elsevier, 1990. http://dx.doi.org/10.1016/b978-0-409-90192-4.50061-3.
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Georgescu, Doina, Ana Lascu, Ioana Ionita, Oana-Elena Ancusa, Mihai Ionita, Ciprian Rosca, Despina Calamar-Popovici und Daniel Lighezan. „Nonalcoholic Fatty Liver Disease, Procalcitonin, and Gut Microbiota: Players in the Same Team“. In Advances in Probiotics for Health and Nutrition [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.110134.
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The study aimed to assess the link between procalcitonin (PCT) and gut dysbiosis in patients with nonalcoholic fatty liver disease (NAFLD). A total of 125 research participants, 100 patients with NAFLD (59% women and 41% men) age between 43 and 84 years and 25 healthy controls, joined this observational study. Patients were consecutively enrolled into two groups: 50 with gut dysbiosis and 50 without gut dysbiosis, after several conditions have been ruled out. Patients from dysbiotic group displayed significantly lesser use of biguanides and statins and elevation of fatty liver index (FLI), PCT, C-reactive protein (CRP), and alanine aminotransferase (ALT). Their gut microbiome was characterized by Bacteroides and Prevotella sp. dominant enterotype (74%) and by Ruminococcus sp. in only 26% of cases. The decrease of H index of biodiversity was observed in 64% of patients as well as of Firmicutes/Bacteroidetes (F/B) ratio and Akkermansia muciniphila in 60%. The increase of lipopolysaccharide positive bacteria was noted in 62% of patients. PCT strongly correlated with the level of CRP and ALT as well as to stool’s H index of biodiversity and F/B ratio. Dysbiotic patients with NAFLD exhibited significant elevation of PCT that correlated well with the H index of stool’s microbiota biodiversity, F/B ratio, CRP level, and severity of cytolytic syndrome.
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Ning, Jing, Shu-Yi Huang, Shi-Dong Chen, Ya-Ru Zhang, Yu-Yuan Huang und Jin-Tai Yu. „Investigating Casual Associations Among Gut Microbiota, Metabolites, and Neurodegenerative Diseases: A Mendelian Randomization Study“. In Advances in Alzheimer’s Disease. IOS Press, 2022. http://dx.doi.org/10.3233/aiad220023.
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Background: Recent studies had explored that gut microbiota was associated with neurodegenerative diseases (including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS)) through the gut-brain axis, among which metabolic pathways played an important role. However, the underlying causality remained unclear. Objective: Our study aimed to evaluate potential causal relationships between gut microbiota, metabolites, and neurodegenerative diseases through Mendelian randomization (MR) approach. Methods: We selected genetic variants associated with gut microbiota traits (N = 18,340) and gut microbiota-derived metabolites (N = 7,824) from genome-wide association studies. Summary statistics of neurodegenerative diseases were obtained from IGAP (AD, 17,008 cases; 37,154 controls), IPDGC (PD, 37,688 cases; 141,779 controls), and IALSC (ALS, 20,806 cases; 59,804 controls) respectively. Results: Greater abundance of Ruminococcus (OR, 1.245; 95%CI, 1.103–1.405; p = 0.0004) was found significantly related to higher risk of ALS. Besides, our study found suggestive associations of Actinobacteria, Lactobacillaceae, Faecalibacterium, Ruminiclostridium, and Lachnoclostridium with AD, of Lentisphaerae, Lentisphaeria, Oxalobacteraceae, Victivallales, Bacillales, Eubacteriumhalliigroup, Anaerostipes, and Clostridiumsensustricto1 with PD, and of Lachnospira, Fusicatenibacter, Catenibacterium, and Ruminococcusgnavusgroup with ALS. Our study also revealed suggestive associations between 12 gut microbiome-dependent metabolites and neurodegenerative diseases. Glutamine was related to lower risk of AD. For the serotonin pathway, serotonin was found as a protective factor of PD, while kynurenine as a risk factor for ALS. Conclusion: Our study firstly applied a two-sample MR approach to detect causal relationships among gut microbiota, gut metabolites, and neurodegenerative diseases. Our findings may provide new targets for treatments and may offer valuable insights for further studies on the underlying mechanisms.
Konferenzberichte zum Thema "Ruminococcus"
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Baumgartner, M., M. Lang, P. Pjevac, B. Hausmann, A. Makristathis, R. Evstatiev, V. Khare, D. Berry, M. Muttenthaler und C. Gasche. „RUMINOCOCCUS GNAVUS 3β-HSDH LINKS MUCOSAL BIOFILMS AND BILE ACID MALABSORPTION“. In 55. Jahrestagung & 32. Fortbildungskurs der Österreichischen Gesellschaft für Gastroenterologie & Hepatologie–ÖGGH (Hybrid Veranstaltung). Georg Thieme Verlag, 2022. http://dx.doi.org/10.1055/s-0042-1755750.
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Azzouz, Doua F., Ze Chen, Peter Izmirly, David Fenyo, Jill Buyon, Alexander V. Alekseyenko und Gregg J. Silverman. „511 Disease flares in lupus are concordant with Ruminococcus Blautia Gnavus blooms arising within unstable gut microbiota communities“. In LUPUS 21ST CENTURY 2021 CONFERENCE, Abstracts of the Fifth Biannual Scientific Meeting of the North and South American and Caribbean Lupus Community, Tucson, Arizona, USA – September 22–25, 2021. Lupus Foundation of America, 2021. http://dx.doi.org/10.1136/lupus-2021-lupus21century.29.
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Azad, R., und S. Mary. „Tentative function and structure prediction of putative genes in the whole genome of gut bacteria ruminococcus champanellensis DSM18848 for the better elucidation of cellular metabolism“. In CONTEMPORARY INNOVATIONS IN ENGINEERING AND MANAGEMENT. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0179097.
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Rayapanani, Azad, und Mary Sanitha. „Tentative function and structure prediction of putative genes in the whole genome of gut bacteria Ruminococcus albus 7 for the better elucidation of cellular metabolism“. In ADVANCES IN SUSTAINABLE CONSTRUCTION MATERIALS. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0116469.
Der volle Inhalt der QuelleBerichte der Organisationen zum Thema "Ruminococcus"
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Morrison, Mark, und Joshuah Miron. Molecular-Based Analysis of Cellulose Binding Proteins Involved with Adherence to Cellulose by Ruminococcus albus. United States Department of Agriculture, November 2000. http://dx.doi.org/10.32747/2000.7695844.bard.
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At the beginning of this project, it was clear that R. albus adhered tightly to cellulose and its efficient degradation of this polysaccharide was dependent on micromolar concentrations of phenylacetic acid (PAA) and phenylpropionic acid (PPA). The objectives for our research were: i) to identify how many different kinds of cellulose binding proteins are produced by Ruminococcus albus; ii) to isolate and clone the genes encoding some of these proteins from the same bacterium; iii) to determine where these various proteins were located and; iv) quantify the relative importance of these proteins in affecting the rate and extent to which the bacterium becomes attached to cellulose. BARD support has facilitated a number of breakthroughs relevant to our fundamental understanding of the adhesion process. First, R. albus possesses multiple mechanisms for adhesion to cellulose. The P.I.'s laboratory has discovered a novel cellulose-binding protein (CbpC) that belongs to the Pil-protein family, and in particular, the type 4 fimbrial proteins. We have also obtained genetic and biochemical evidence demonstrating that, in addition to CbpC-mediated adhesion, R. albus also produces a cellulosome-like complex for adhesion. These breakthroughs resulted from the isolation (in Israel and the US) of spontaneously arising mutants of R. albus strains SY3 and 8, which were completely or partially defective in adhesion to cellulose, respectively. While the SY3 mutant strain was incapable of growth with cellulose as the sole carbon source, the strain 8 mutants showed varying abilities to degrade and grow with cellulose. Biochemical and gene cloning experiments have been used in Israel and the US, respectively, to identify what are believed to be key components of a cellulosome. This combination of cellulose adhesion mechanisms has not been identified previously in any bacterium. Second, differential display, reverse transcription polymerase chain reaction (DD RT-PCR) has been developed for use with R. albus. A major limitation to cellulose research has been the intractability of cellulolytic bacteria to genetic manipulation by techniques such as transposon mutagenesis and gene displacement. The P.I.'s successfully developed DD RT- PCR, which expanded the scope of our research beyond the original objectives of the project, and a subset of the transcripts conditionally expressed in response to PAA and PPA have been identified and characterized. Third, proteins immunochemically related to the CbpC protein of R. albus 8 are present in other R. albus strains and F. intestinalis, Western immunoblots have been used to examine additional strains of R. albus, as well as other cellulolytic bacteria of ruminant origin, for production of proteins immunochemically related to the CbpC protein. The results of these experiments showed that R. albus strains SY3, 7 and B199 all possess a protein of ~25 kDa which cross-reacts with polyclonal anti-CbpC antiserum. Several strains of Butyrivibrio fibrisolvens, Ruminococcus flavefaciens strains C- 94 and FD-1, and Fibrobacter succinogenes S85 produced no proteins that cross-react with the same antiserum. Surprisingly though, F. intestinalis strain DR7 does possess a protein(s) of relatively large molecular mass (~200 kDa) that was strongly cross-reactive with the anti- CbpC antiserum. Scientifically, our studies have helped expand the scope of our fundamental understanding of adhesion mechanisms in cellulose-degrading bacteria, and validated the use of RNA-based techniques to examine physiological responses in bacteria that are nor amenable to genetic manipulations. Because efficient fiber hydrolysis by many anaerobic bacteria requires both tight adhesion to substrate and a stable cellulosome, we believe our findings are also the first step in providing the resources needed to achieve our long-term goal of increasing fiber digestibility in animals.
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Morrison, Mark, Joshuah Miron, Edward A. Bayer und Raphael Lamed. Molecular Analysis of Cellulosome Organization in Ruminococcus Albus and Fibrobacter Intestinalis for Optimization of Fiber Digestibility in Ruminants. United States Department of Agriculture, März 2004. http://dx.doi.org/10.32747/2004.7586475.bard.
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Improving plant cell wall (fiber) degradation remains one of the highest priority research goals for all ruminant enterprises dependent on forages, hay, silage, or other fibrous byproducts as energy sources, because it governs the provision of energy-yielding nutrients to the host animal. Although the predominant species of microbes responsible for ruminal fiber degradation are culturable, the enzymology and genetics underpinning the process are poorly defined. In that context, there were two broad objectives for this proposal. The first objective was to identify the key cellulosomal components in Ruminococcus albus and to characterize their structural features as well as regulation of their expression, in response to polysaccharides and (or) P AA/PPA. The second objective was to evaluate the similarities in the structure and architecture of cellulosomal components between R. albus and other ruminal and non-ruminal cellulolytic bacteria. The cooperation among the investigators resulted in the identification of two glycoside hydrolases rate-limiting to cellulose degradation by Ruminococcus albus (Cel48A and CeI9B) and our demonstration that these enzymes possess a novel modular architecture specific to this bacterium (Devillard et al. 2004). We have now shown that the novel X-domains in Cel48A and Cel9B represent a new type of carbohydrate binding module, and the enzymes are not part of a ceiluiosome-like complex (CBM37, Xu et al. 2004). Both Cel48A and Cel9B are conditionally expressed in response to P AA/PPA, explaining why cellulose degradation in this bacterium is affected by the availability of these compounds, but additional studies have shown for the first time that neither PAA nor PPA influence xylan degradation by R. albus (Reveneau et al. 2003). Additionally, the R. albus genome sequencing project, led by the PI. Morrison, has supported our identification of many dockerin containing proteins. However, the identification of gene(s) encoding a scaffoldin has been more elusive, and recombinant proteins encoding candidate cohesin modules are now being used in Israel to verify the existence of dockerin-cohesin interactions and cellulosome production by R. albus. The Israeli partners have also conducted virtually all of the studies specific to the second Objective of the proposal. Comparative blotting studies have been conducted using specific antibodies prepare against purified recombinant cohesins and X-domains, derived from cellulosomal scaffoldins of R. flavefaciens 17, a Clostridium thermocellum mutant-preabsorbed antibody preparation, or against CbpC (fimbrial protein) of R. albus 8. The data also suggest that additional cellulolytic bacteria including Fibrobacter succinogenes S85, F. intestinalis DR7 and Butyrivibrio fibrisolvens Dl may also employ cellulosomal modules similar to those of R. flavefaciens 17. Collectively, our work during the grant period has shown that R. albus and other ruminal bacteria employ several novel mechanisms for their adhesion to plant surfaces, and produce both cellulosomal and non-cellulosomal forms of glycoside hydrolases underpinning plant fiber degradation. These improvements in our mechanistic understanding of bacterial adhesion and enzyme regulation now offers the potential to: i) optimize ruminal and hindgut conditions by dietary additives to maximize fiber degradation (e.g. by the addition of select enzymes or PAA/PPA); ii) identify plant-borne influences on adhesion and fiber-degradation, which might be overcome (or improved) by conventional breeding or transgenic plant technologies and; iii) engineer or select microbes with improved adhesion capabilities, cellulosome assembly and fiber degradation. The potential benefits associated with this research proposal are likely to be realized in the medium term (5-10 years).
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Chaparro, Martha Liliana, Erika Grijalba Bernal, Fernando Rodríguez Villamizar und Martha Isabel Gómez Álvarez. Estabilidad de las cepas anaerobicas Butyrivibrio fibrisolvens (Bg) streptococcus bovis (C2), Ruminococcus flavefaciens (Rf) y Fibrobacter Succinogenes (Fs) Formuladas en el vehículo oleoso. Corporación Colombiana de Investigación Agropecuaria - AGROSAVIA, 2018. http://dx.doi.org/10.21930/agrosavia.poster.2018.9.
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En Colombia la morbilidad de terneros neonatos causada por la incidencia de diarreas puede alcanzar un 60%, con una morbilidad cercana a un 20% (Aldana et al., 2009).Para su tratamiento generalmente se emplean antibióticos que disminuye la calidad de la leche y aumentan la resistencia de los patógenoa a los agentes antimicrobiales (FAO, 2016). En AGROSAVIA, se seleccionó un coctel microbiano formado por bacterias aisladas de bovinos nativos, que consistió en cuatro bacterias ruminales anaerobicas que redujeron la incidencia de diarreas hasta un en 65% en terneros neonatos. Para estas bacterias se diseño una formulación (emulsión) que busca proteger a las bacterias reduciendo su contacto con oxígeno.