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multiple endoxylanases of butyrivibrio sp.butyrivibrio sp. mz 5 with a high xylanolytic activity was isolated. four major xylanases were detected in the cell-associated fraction using the zymogram technique. the xylanolytic activity was inducible with the oat spelts xylan; two endoxylanases (51 and 145 kda) were formed constitutively. the bulk of the xylanolytic activity was cell-bound and growth-phase dependent; the maximum activity in the cell-associated fraction was achieved after 16 h of incubation. the highest xylanolytic activity ...200111501489
the effect of condensed tannins from lotus pedunculatus and lotus corniculatus on the growth of proteolytic rumen bacteria in vitro and their possible mode of action.five strains of proteolytic rumen bacteria were treated with condensed tannins (ct) purified from lotus pedunculatus and lotus corniculatus to investigate their effect on the growth of these bacteria in vitro. streptococcus bovis ncfb 2476, eubacterium sp. c124b, prevotella bryantii b14, butyrivibrio fibrisolvens h17c, and clostridium proteoclasticum b316t were tested against 200, 400, and 600 microg ct x ml(-1) extracted from l. pedunculatus and l. corniculatus. in the absence of ct, all bacter ...200111547882
paex, a second pectin acetylesterase of erwinia chrysanthemi 3937.erwinia chrysanthemi causes soft-rot diseases of various plants by enzymatic degradation of the pectin in plant cell walls. pectin is a complex polysaccharide. the main chain is constituted of galacturonate residues, and some of them are modified by methyl and/or acetyl esterification. esterases are necessary to remove these modifications and, thus, to facilitate the further degradation of the polysaccharidic chain. in addition to paey, the first pectin acetylesterase identified in the e. chrysa ...200312730169
the adaptation and resistance of clostridium aminophilum f to the butyrivibriocin-like substance of butyrivibrio fibrisolvens jl5 and monensin.when the amino acid-fermenting bacterium clostridium aminophilum f was inoculated into media containing 1 microm monensin or a bacteriocin-like inhibitory substance (blis) from butyrivibrio fibrisolvens jl5, the cultures lagged and growth was not observed for more than 12 h. the monensin- and blis-treated cultures eventually grew rapidly and did not lag a second time. because cross-resistance could not be demonstrated, it appeared that the adaptation was specific. non-adapted cells that were inc ...200212007660
transformation and expression of an anaerobic fungal xylanase in several strains of the rumen bacterium butyrivibrio fibrisolvens.to obtain reliable transformation of a range of butyrivibrio fibrisolvens strains and to express a neocallimastix patriciarum xylanase gene in the recipients.200212067381
horizontal transfer of erythromycin resistance from clostridium difficile to butyrivibrio fibrisolvens.this study demonstrates for the first time the in vitro transfer of the erythromycin resistance gene erm(b) between two obligate anaerobes, the human spore-forming pathogen clostridium difficile and the rumen commensal butyrivibrio fibrisolvens, suggesting that this event might occur also in the natural environment.200516304188
lotus corniculatus condensed tannins decrease in vivo populations of proteolytic bacteria and affect nitrogen metabolism in the rumen of sheep.condensed tannins in forage legumes improve the nutrition of sheep by reducing ruminal degradation of plant protein and increasing crude protein flow to the intestine. however, the effects of condensed tannins in forage legumes on rumen bacterial populations in vivo are poorly understood. the aim of this study was to investigate the specific effects of condensed tannins from lotus corniculatus on four proteolytic rumen bacteria in sheep during and after transition from a ryegrass (lolium perenne ...200212489781
isolation and fermentation characteristics of strains of butyrivibrio from ruminal ingesta. 195913664653
nutritional characteristics of a butyrivibrio. 195813549370
isolation, enumeration, and characteristics of proteolytic ruminal bacteria.fulghum, robert s. (virginia polytechnic institute, blacksburg) and w. e. c. moore. isolation, enumeration, and characteristics of proteolytic ruminal bacteria. j. bacteriol. 85:808-815. 1963.-colony counts of proteolytic ruminal bacteria in the order of 10(9) organisms per g of whole rumen contents, and total colony counts in the order of 2 to 3 x 10(9) organisms per g, were obtained from rumen contents of cattle fed a maintenance ration of hay and grain. the proteolytic counts averaged 38% of ...196314044947
serological analysis of butyrivibrio from the bovine rumen.margherita, s. s. (university of california, davis) and r. e. hungate. serological analysis of butyrivibrio from the bovine rumen. j. bacteriol. 86:855-860. 1963.-the cultural and fermentation characteristics of a number of strains of butyrivibrio fibrisolvens isolated from the bovine rumen of cattle from different areas were determined, and the strains were subjected to serological analysis by the techniques of agglutination, immunodiffusion, and indirect hemolysis. in general, the results of t ...196314066485
biohydrogenation of unsaturated fatty acids by rumen bacteria.polan, c. e. (north carolina state of the university of north carolina, raleigh), j. j. mcneill, and s. b. tove. biohydrogenation of unsaturated fatty acids by rumen bacteria. j. bacteriol. 88:1056-1064. 1964.-a simple, rapid, specific assay for the biohydrogenation of unsaturated fatty acids was developed. with this assay, it was shown that washed suspensions of mixed rumen bacteria hydrogenate linoleic and oleic acids. butyrivibrio fibrisolvens, a common rumen bacterium, is capable of hydrogen ...196414219019
novel tetracycline resistance gene, tet(32), in the clostridium-related human colonic anaerobe k10 and its transmission in vitro to the rumen anaerobe butyrivibrio fibrisolvens.a novel tetracycline resistance gene, designated tet(32), which confers a high level of tetracycline resistance, was identified in the clostridium-related human colonic anaerobe k10, which also carries tet(w). tet(32) was transmissible in vitro to the rumen anaerobe butyrivibrio fibrisolvens 2221(r). the predicted gene product of tet(32) has 76% amino acid identity with tet(o). pcr amplification indicated that tet(32) is widely distributed in the ovine rumen and in porcine feces.200111600392
high-frequency transfer of a naturally occurring chromosomal tetracycline resistance element in the ruminal anaerobe butyrivibrio fibrisolvens.butyrivibrio fibrisolvens strains resistant to tetracycline were isolated from the bovine rumen. two of three tcr b. fibrisolvens tested were able to donate tetracycline resistance at frequencies ranging from 10(-7) to 10(-1) per donor cell in anaerobic filter matings to a rifampin-resistant mutant of the type strain of b.fibrisolvens, 2221r. the recipient strain 2221r exhibited rapid autoaggregation, which might be a factor in the high transfer rates observed. tcr transconjugants of b. fibrisol ...19979292992
presence of butyrivibrio fibrisolvens in the digestive tract of dogs and cats, and its contribution to butyrate production.numbers of butyrivibrio fibrisolvens, a major butyrate-producing bacterium in the rumen, in feces of dogs and cats were estimated by competitive pcr. the type iib of b. fibrisolvens, which produces much more lactate than butyrate, was detected at the levels (cells per g of feces dry weight) of 2.4x10(3)-9.0x10(5) for dogs and 1.7x10(4-)-6.2x10(5) for cats. however, the type i that produces much more butyrate than the type iib was not detected in cat or dog feces (less than 6.0x10(4) cells per g ...200112483606
partial inhibition of biohydrogenation of linoleic acid can increase the conjugated linoleic acid production of butyrivibrio fibrisolvens a38.butyrivibrio fibrisolvens a38, one of the most active rumen bacteria in conjugated linoleic acid (cla) production, was characterized in vitro. previous findings that some inhibitory levels of substrate for biohydrogenation (bh) by b. fibrisolvens a38 resulted in more cla accumulation led to a prediction that partial inhibition of bh could increase ruminal cla production. the inhibitory conditions for bacterial growth were less effective on the isomerization step than on the following reduction s ...200312848494
comparison of substrate affinities among several rumen bacteria: a possible determinant of rumen bacterial competition.five rumen bacteria, selenomonas ruminantium, bacteroides ruminicola, megasphaera elsdenii, streptococcus bovis, and butyrivibrio fibrisolvens were grown in continuous culture. estimates of substrate affinities were derived from lineweaver-burk plots of dilution rate versus substrate concentration. each bacterium was grown on at least four of the six substrates: glucose, maltose, sucrose, cellobiose, xylose, and lactate. wide variations in substrate affinities were seen among the substrates util ...197916345358
comparison of maintenance energy expenditures and growth yields among several rumen bacteria grown on continuous culture.maintenance energy expenditures were mesured for five rumen bacteria, selenomonas ruminantium, butyrivibrio fibrisolvens, bacteroides ruminicola, megasphaera elsdenii, and streptococcus bovis, by using a complex medium with glucose as the carbon source. large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. the suggestion is made that maintenance requirements could be a significant determinant of bacterial competition in the rumen. theoretical ...197916345359
degradation of bermuda and orchard grass by species of ruminal bacteria.fiber degradation in bermuda grass and orchard grass was evaluated gravimetrically and by scanning and transmission electron microscopy after incubation with pure cultures of rumen bacteria. lachnospira multiparus d-32 was unable to degrade plant cell wall components. butyrivibrio fibrisolvens 49 degraded 6 and 14.9% of the fiber components in bermuda grass and orchard grass, respectively, and ruminococcus albus 7 degraded 11.4% orchard grass fiber but none in bermuda grass. both b. fibrisolvens ...198516346915
effect of 3-phenylpropanoic acid on growth of and cellulose utilization by cellulolytic ruminal bacteria.the growth of several cellulolytic species of ruminal bacteria was measured in media containing either cellobiose or cellulose as the energy source and with or without added 3-phenylpropanoic acid (ppa). with ruminoccoccus albus 7 and 8, the addition of ppa greatly enhanced the rate of cellulose utilization but had little effect on the rate of growth when cellobiose was the energy source. comparative rates of growth obtained on either cellobiose or cellulose for ruminococcus flavefaciens fd1 or ...198616347111
effects of combinations of substrates on maximum growth rates of several rumen bacteria.five rumen bacteria, selenomonas ruminantium, bacteroides ruminicola, megasphaera elsdenii, butyrivibrio fibrisolvens, and streptococcus bovis were grown in media containing nonlimiting concentrations of glucose, sucrose, maltose, cellobiose, xylose and/or lactate. each bacterium was grown with every substrate that it could ferment in every possible two-way combination. only once did a combination of substrates result in a higher maximum growth rate than that observed with either substrate alone ...197916345360
oxaloacetate synthesis in butyrivibrio fibrisolvens.phosphoenolpyruvate carboxykinase (adenosine 5'-triphosphate) was the only enzyme capable of carboxylating pyruvate or phosphoenolpyruvate that could be demonstrated in sonicated cells or cell-free extracts of a group 1 butyrivibrio.197916345406
variation in antimicrobial action of proanthocyanidins from dorycnium rectum against rumen bacteria.the proanthocyanidin polymer fractions of the leaves of the forage legume dorycnium rectum were analysed by acid catalysis with benzyl mercaptan, nmr and es-ms. the results showed that d. rectum differs from other temperate proanthocyanidin-containing forage legumes in that the range of polymers extends up to very high degrees of polymerisation. three fractions were characterised as low, medium, and high molecular weight proanthocyanidin fractions with mean degree of polymerisations of 10.3, 41 ...200415381413
effect of monensin and lasalocid-sodium on the growth of methanogenic and rumen saccharolytic bacteria.it is thought that monensin increases the efficiency of feed utilization by cattle by altering the rumen fermentation. we studied the effect of monensin and the related ionophore antibiotic lasalocid-sodium (hoffman-laroche) on the growth of methanogenic and rumen saccharolytic bacteria in a complex medium containing rumen fluid. ruminococcus albus, ruminococcus flavefaciens, and butyrivibrio fibrisolvens were inhibited by 2.5 mug of monensin or lasalocid per ml. growth of bacteroides succinogen ...197916345418
oxaloacetate synthesis in butyrivibrio fibrisolvens.[this corrects the article on p. 1247 in vol. 37.].197916345454
electron microscopy of the microbial populations present and their modes of attack on various cellulosic substrates undergoing digestion in the sheep rumen.cotton fibers and various cell wall preparations from grass leaves and from the feces of sheep fed on dried grass were placed in the sheep rumen in bags made from 5-mum-mesh nylon cloth. after periods of from 3 to 48 h, bags were removed, and the contents were fixed, embedded, sectioned, and stained for electron microscopy. some of the bacteria present were seen to be closely associated with the cell walls, either tunneling within them or making very close contact. evidence was obtained for diff ...197816345303
effects of sainfoin (onobrychis viciifolia scop.) condensed tannins on growth and proteolysis by four strains of ruminal bacteria.sainfoin leaf condensed tannins inhibited growth and protease activity in butyrivibrio fibrisolvens a38 and streptococcus bovis 45s1 but had little effect on prevotella ruminicola b(1)4 or ruminobacter amylophilus wp225. tannins bound to cell coat polymers in all strains. morphological changes in b. fibrisolvens and s. bovis implicated the cell wall as a target of tannin toxicity.199416349244
bacteriocin-like activity of butyrivibrio fibrisolvens jl5 and its effect on other ruminal bacteria and ammonia production.when ruminal bacteria from a cow fed hay were serially diluted into an anaerobic medium that had only peptides and amino acids as energy sources, little growth or ammonia production was detected at dilutions greater than 10(-6). the 10(-8) and 10(-9) dilutions contained bacteria that fermented carbohydrates, and some of these bacteria inhibited clostridium sticklandii sr, an obligate amino acid-fermenting bacterium. phylogenetic analysis indicated that the most active isolate (jl5) was closely r ...200211872448
widespread distribution of a tet w determinant among tetracycline-resistant isolates of the animal pathogen arcanobacterium pyogenes.tetracycline resistance is common among isolates of the animal commensal and opportunistic pathogen arcanobacterium pyogenes. the tetracycline resistance determinant cloned from two bovine isolates of a. pyogenes was highly similar at the dna level (92% identity) to the tet(w) gene, encoding a ribosomal protection tetracycline resistance protein, from the rumen bacterium butyrivibrio fibrisolvens. the tet(w) gene was found in all 20 tetracycline-resistant isolates tested, indicating that it is a ...200211959557
enrichment and isolation of rumen bacteria that reduce trans- aconitic acid to tricarballylic acid.bacteria from the bovine rumen capable of reducing trans-aconitate to tricarballylate were enriched in an anaerobic chemostat containing rumen fluid medium and aconitate. after 9 days at a dilution rate of 0.07 h, the medium was diluted and plated in an anaerobic glove box. three types of isolates were obtained from the plates (a crescent-shaped organism, a pleomorphic rod, and a spiral-shaped organism), and all three produced tricarballylate in batch cultures that contained glucose and trans-ac ...198516346691
isolation of a novel strain of butyrivibrio fibrisolvens that isomerizes linoleic acid to conjugated linoleic acid without hydrogenation, and its utilization as a probiotic for animals.isolation of a new strain of butyrivibrio fibrisolvens possessing great capacity to produce conjugated linoleic acid (cla) in order to utilize as a probiotic for animals.200616553734
influence of forage phenolics on ruminal fibrolytic bacteria and in vitro fiber degradation.in vitro cultures of ruminal microorganisms were used to determine the effect of cinnamic acid and vanillin on the digestibility of cellulose and xylan. cinnamic acid and vanillin depressed in vitro dry matter disappearance of cellulose 14 and 49%, respectively, when rumen fluid was the inoculum. the number of viable bacteroides succinogenes cells, the predominant cellulolytic organism, was threefold higher for fermentations which contained vanillin than for control fermentations. when xylan rep ...198616347127
isolation and characterization of xylan-degrading strains of butyrivibrio fibrisolvens from a napier grass-fed anaerobic digester.six new xylanolytic bacterial strains have been isolated from a napier grass-fed anaerobic digester. these strains were identified as butyrivibrio fibrisolvens and were similar in many respects to ruminal isolates described previously. the new isolates exhibited a high degree of dna homology with several ruminal strains of b. fibrisolvens. xylan or xylose was required to induce the production of enzymes for xylan degradation, xylanase and xylosidase. production of these enzymes was repressed in ...198816347622
digestion of barley, maize, and wheat by selected species of ruminal bacteria.differences in the digestion of barley, maize, and wheat by three major ruminal starch-digesting bacterial species, streptococcus bovis 26, ruminobacter amylophilus 50, and butyrivibrio fibrisolvens a38, were characterized. the rate of starch digestion in all cereal species was greater for s. bovis 26 than for r. amylophilus 50 or b. fibrisolvens a38. starch digestion by s. bovis 26 was greater in wheat than in barley or maize, whereas starch digestion by r. amylophilus 50 was greater in barley ...199016348322
anaerobic production of extracellular polysaccharide by butyrivibrio fibrisolvens nyx.anaerobic production of extracellular polysaccharide (ep) was examined, using a previously uncharacterized, obligately anaerobic rumen isolate, butyrivibrio fibrisolvens nyx, which produced an ep that was rheologically similar to xanthan gum. the main objectives were to determine the nutritional requirements and conditions which promoted ep production by strain nyx. strain nyx was grown anaerobically in defined and semidefined media. in addition to carbohydrate and nitrogen sources, strain nyx r ...199216348636
butyrivibrio hungatei sp. nov. and pseudobutyrivibrio xylanivorans sp. nov., butyrate-producing bacteria from the rumen.two novel gram-negative, anaerobic, non-spore-forming, butyrate-producing bacterial species, strains mz 5t and jk 615t, were isolated from the rumen fluid of cow and sheep. both strains were curved rods that were motile by means of single polar or subpolar flagellum and common in the rumen microbial ecosystem. strain mz 5t produced high xylanase, proteinase, pectin hydrolase and dnase activities; 1,4-beta-endoglucanase was also detected in the culture medium. the bacterium utilized a wide range ...200312656174
characterization and transcription of the genes encoding enzymes involved in butyrate production in butyrivibrio fibrisolvens.genes encoding enzymes that catalyze butyryl-coa formation from acetyl-coa in a type ii strain of butyrivibrio fibrisolvens were analyzed. the genes encoding thiolase, beta-hydroxybutyryl-coa dehydrogenase, butyryl-coa dehydrogenase, and electron transfer flavoproteins were clustered, but the crotonase gene was not present in this region. the deduced amino acid sequences of these enzymes were similar to those of clostridia. the clustered genes were shown to be cotranscribed. the rate of butyrate ...200314570270
phylogenetic analysis of fiber-associated rumen bacterial community and pcr detection of uncultured bacteria.the fiber-associated rumen bacterial community was phylogenetically examined by analysis of 16s rrna gene (16s rdna) sequences. hay stems of orchardgrass and alfalfa were incubated for 6 and 20 h, respectively in the rumen of two different sheep, and total dna was extracted from the incubated stems to clone bacterial 16s rdnas using polymerase chain reaction (pcr). of 91 such clones, 21 showed more than 97% sequence similarity with known isolates, 32 clones had 90-97% similarity with known seque ...200314659538
utilization of glucose and xylose in ruminal strains of butyrivibrio fibrisolvens.the dual-substrate utilization pattern in cultures of five ruminal strains of butyrivibrio fibrisolvens growing on glucose and xylose was investigated. strains atcc 19171 and 86 utilized glucose and xylose simultaneously. other strains exhibited diauxic growth. strains x1 and ce 51 exhibited classical diauxic growth in which glucose was utilized during the first phase. strain x2d62 displayed atypical diauxic growth in which slow utilization of xylose was followed by rapid utilization of glucose ...199416349201
bacterial population adherent to the epithelium on the roo of the dorsal rumen of sheep.by anaerobic procedures, the total number of adherent bacteria was determined on tissue samples obtained from the roof of the dorsal rumen of three sheep. after four washings, 1.91 x 10, 0.34 x 10, and 1.23 x 10 bacteria per cm were still attached to the rumen epithelium in sheep 1, 2, and 3, respectively. a total of 95 strains of bacteria were isolated from these three samples. based on morphology, gram stain, anaerobiosis, motility, and fermentation end products, they were presumptively identi ...198116345797
isolation of plasmid dna from butyrivibrio fibrisolvens.a procedure based on successive precipitation of cell lysates with sodium dodecyl sulfate-nacl and polyethylene glycol 6000 was developed which allows the isolation of plasmid dna from butyrivibrio fibrisolvens. a survey of b. fibrisolvens strains isolated from the bovine rumen showed that plasmids are a common feature of this species.198216345935
effects of exogenous ammonia or free amino acids on proteolytic activity and protein breakdown products in streptococcus bovis, prevotella albensis, and butyrivibrio fibrisolvens.we studied in details the ammonia or free amino acids (aa) effects on proteolytic activity of three ruminal bacteria: enzymatic activities and protein breakdown products were measured at the end of the exponential growth phase. in streptococcus bovis the simultaneous uptake of ammonia and probably small peptides induced a decline in total proteolytic activity as a result of changes in endopeptidasic activities. with free aa, the tendency for the endopeptidasic activities to specialise was more e ...200212000995
butyrivibriocin ar10, a new cyclic bacteriocin produced by the ruminal anaerobe butyrivibrio fibrisolvens ar10: characterization of the gene and peptide.the gene (bvia) encoding the ruminal bacteriocin butyrivibriocin ar10 was cloned from an ecori library by using an oligonucleotide probe based on a partial peptide sequence of the previously isolated peptide. the gene encoded an 80 amino acid prebacteriocin that demonstrated significant identity with the cyclic bacteriocin gassericin a. negative ion time of flight mass spectroscopic analysis (esi/ms) indicated a mass of 5981.5 da for the isolated bacteriocin, a molecular mass that could not be g ...200315162201
effects of long-chain fatty acids on growth of rumen bacteria.the effects of low concentrations of long-chain fatty acids (palmitic, stearic, oleic, and vaccenic) on the growth of seven species (13 strains) of rumen bacteria were investigated. except for bacteroides ruminicola and several strains of butyrivibrio fibrisolvens, bacterial growth was not greatly affected by either palmitic or stearic acids. in contrast, growth of selenomonas ruminantium, b. ruminicola, and one strain of b. fibrisolvens was stimulated by oleic acid, whereas the cellulolytic spe ...198116345887
characterization and transcription of the genes involved in butyrate production in butyrivibrio fibrisolvens type i and ii strains.the genes in butyrivibrio fibrisolvens that encode the enzymes involved in butyrate production were sequenced. in a type i strain (atcc 19171(t)), the genes coding for the enzymes that catalyze the conversion from acetyl-coa to butyryl-coa, thl (thiolase), crt (crotonase), hbd (beta-hydroxybutyryl-coa dehydrogenase), bcd (butyryl-coa dehydrogenase), etfb (electron transfer flavoprotein [etf]-beta), and etfa (etf-alpha), were found to be clustered and arranged in this order. a type ii strain (atc ...200515991056
assessment of biases associated with profiling simple, model communities using terminal-restriction fragment length polymorphism-based analyses.community profiles based on terminal-restriction fragment length polymorphism (t-rflp) analyses of amplified ribosomal rna genes are used to monitor changes in microbial community structure and are sometimes employed for semi-quantitative estimates of species richness and abundance in environmental samples. to assess the accuracy of t-rflp community profiles representing the relative abundance of bacteria in a sample, five species of ruminal bacteria were used to construct simple "communities". ...200616563536
structural studies of the extracellular polysaccharide produced by butyrivibrio fibrisolvens strain h10b.the extracellular polysaccharide produced by butyrivibrio fibrisolvens strain h10b, when grown under strictly anaerobic conditions with glucose as carbohydrate source, has been studied by chemical and spectroscopic techniques. the results demonstrate that the polysaccharide consists of hexasaccharide repeating units with the following structure: [structure: see text] the isolated polysaccharide was found to be approximately 65% acetylated at o-2 of the 3-o-[(s)-1-carboxyethyl]-beta-d-glcp residu ...200312860428
[metabolism of rumen microbial populations formed on biosubstrates with different assimilation under the effect of pentachlorophenol].it has been established that metabolism of mixed microbial population formed on easy assimilated sources of energy and nitrogen (concentrate diet) progressed on higher level. there is increase of amilolytic activity, formation of lactate, ammonia, low molecular carbonic acids with predomination of propionate molar fraction. the increased resistance to effect of pentachlorophenol (pcp) is characteristic nature of the latter. the role of the most resistant synthrophic bacteria to pcp increases. th ...200212916235
comparative analysis of sequences flanking tet(w) resistance genes in multiple species of gut bacteria.tet(w) is one of the most abundant tetracycline resistance genes found in bacteria from the mammalian gut and was first identified in the rumen anaerobe butyrivibrio fibrisolvens 1.230, where it is highly mobile and its transfer is associated with the transposable chromosomal element tnb1230. in order to compare the genetic basis for tet(w) carriage in different bacteria, we studied sequences flanking tet(w) in representatives of seven bacterial genera originating in diverse gut environments. th ...200616870752
expression and export of a ruminococcus albus cellulase in butyrivibrio fibrisolvens through the use of an alternative gene promoter and signal sequence.ruminococcal cellulase (ruminococcus albus f-40 endoglucanase egi) was successfully expressed in butyrivibrio fibrisolvens ob156c, using the erm promoter from pambeta1. a newly identified signal peptide coding region of xyna from b. fibrisolvens 49 allowed efficient translocation of the foreign egi into the extracellular fraction. first, b. fibrisolvens xyna with or without its own putative signal peptide (xyna sp) coding region was cloned into a shuttle vector to transform b. fibrisolvens ob156 ...200314569291
use of community genome arrays (cgas) to assess the effects of acacia angustissima on rumen ecology.this research developed a community genome array (cga) to assess the effects of acacia angustissima on rumen microbiology. a. angustissima produces non-protein amino acids as well as tannins, which may be toxic to animals, and cga was used to assess the effects of this plant on the ecology of the rumen. cgas were developed using a 7.5 cmx2.5 cm nylon membrane format that included up to 96 bacterial genomes. it was possible to separately hybridize large numbers of membranes at once using this min ...200415347749
the butyrivibrio fibrisolvens tet(w) gene is carried on the novel conjugative transposon tnb1230, which contains duplicated nitroreductase coding sequences.the butyrivibrio fibrisolvens tet(w) gene is located on the conjugative transposon tnb1230. tnb1230 encodes transfer proteins with 48 to 67% identity to some of those encoded by tn1549. tet(w) is flanked by directly repeated sequences with significant homology to oxygen-insensitive nitroreductases. the 340 nucleotides upstream of tet(w) are strongly conserved and are required for tetracycline resistance.200415150255
effect of the microbial feed additive saccharomyces cerevisiae cncm i-1077 on protein and peptide degrading activities of rumen bacteria grown in vitro.we investigated the potential of the ruminant feed additive saccharomyces cerevisiae cncm i-1077 on protein and peptide degrading activities of the rumen bacterial species prevotella albensis m384, streptococcus bovis 20480, and butyrivibrio fibrisolvens 3071 grown in vitro. alive or heat-killed yeast cells were added to bacterial cultures in a complex casein-glucose medium. after incubation of the cultures at 39 degrees c under o(2)-free co(2), peptidase activities were determined in the absenc ...200515702254
quantification of ruminal clostridium proteoclasticum by real-time pcr using a molecular beacon approach.all members of the ruminal butyrivibrio group convert linoleic acid (cis-9,cis-12-18:2) via conjugated 18:2 metabolites (mainly cis-9,trans-11-18:2, conjugated linoleic acid) to vaccenic acid (trans-11-18:1), but only members of a small branch, which includes clostridium proteoclasticum, of this heterogeneous group further reduce vaccenic acid to stearic acid (18:0, sa). the aims of this study were to develop a real-time polymerase chain reaction (pcr) assay that would detect and quantify these ...200717897229
a new strain of butyrivibrio fibrisolvens that has high ability to isomerize linoleic acid to conjugated linoleic acid.a new strain of butyrivibrio fibrisolvens (th1) that has high potential to produce conjugated linoleic acid (cla) was isolated. strain th1 had higher la isomerase (la-i) activity, and was much more tolerant to linoleic acid (la) than other strains examined. however, high cla reductase (cla-r) activity resulted in the temporary accumulation of cla and subsequent conversion to trans-vaccenic acid (t-va). when la was added to growing th1 cultures in a solution with dimethylsulfoxide (la/dmso), cla ...200515942871
genetic diversity of viable, injured, and dead fecal bacteria assessed by fluorescence-activated cell sorting and 16s rrna gene analysis.a novel approach combining a flow cytometric in situ viability assay with 16s rrna gene analysis was used to study the relationship between diversity and activity of the fecal microbiota. simultaneous staining with propidium iodide (pi) and syto bc provided clear discrimination between intact cells (49%), injured or damaged cells (19%), and dead cells (32%). the three subpopulations were sorted and characterized by denaturing gradient gel electrophoresis (dgge) of 16s rrna gene amplicons obtaine ...200516085863
purification and characterization of an alpha-l-arabinofuranosidase from butyrivibrio fibrisolvens gs113.an alpha-l-arabinofuranosidase (ec 3.2.1.55) was purified from the cytoplasm of butyrivibrio fibrisolvens gs113. the native enzyme had an apparent molecular mass of 240 kda and was composed of eight polypeptide subunits of 31 kda. the enzyme displayed an isoelectric point of 6.0, a ph optimum of 6.0 to 6.5, a ph stability of 4.0 to 8.0, and a temperature optimum of 45 degrees c and was stable to 55 degrees c. the k(m) and v(max) for p-nitrophenyl-alpha-l-arabinofuranoside were 0.7 mm and 109 mum ...199216348679
effect of low-roughage diets on the microflora and lipid metabolism in the rumen.changing the diet of five lactating cows and one nonlactating cow from high to low roughage induced milk fat depression in the lactating cows and altered the composition of the rumen microflora. while the numbers of lactic and propionic acid-producing bacteria increased, the numbers of butyrivibrio spp. decreased. the numbers of lipolytic bacteria and the in vitro lipolytic activity of the rumen fluid were also decreased, as was the extent of hydrogenation of linoleic and linolenic acids combine ...197216349951
extracellular metabolomics: a metabolic footprinting approach to assess fiber degradation in complex media.this work reports the implementation and optimization of a method for high-throughput analysis of metabolites produced by the breakdown of natural polysaccharides by microorganisms. our simple protocol enables simultaneous separation and quantification of more than 40 different sugars and sugar derivatives, in addition to several organic acids in complex media, using 50-mul samples and a standard gas chromatography-mass spectrometry platform that was fully optimized for this purpose. as an imple ...200616356465
antimicrobial susceptibility of bifidobacterium strains from humans, animals and probiotic products.the aim of this study was to assess the antimicrobial susceptibility of a taxonomically diverse set of bifidobacterium strains to different classes of antimicrobial agents using a recently described medium.200616698847
butyrivibrio spp. and other xylanolytic microorganisms from the rumen have cinnamoyl esterase activity.high concentrations of hydroxycinnamic acids in the hemicellulosic fraction of dry season tropical grasses may influence the rate of microbial degradation of arabinoxylans by ruminant animals. the ability of 22 strains of butyrivibrio fibrisolvens, other ruminal bacteria (ruminococcus albus sy3, ruminococcus flavefaciens rf1,prevotella ruminicola ar20) and the ruminal phycomycete neocallimastix patriciarum cx to digest the tropical grass heteropogon contortus(spear grass) and hydrolyse esterifie ...199816887624
occurrence of restriction-modification systems in ruminal butyrate-producing bacteria.thirty-five strains of ruminal bacteria belonging to the former butyrivibrio fibrisolvens species were screened for the presence of site-specific restriction endonuclease and modification methyltransferase activities. seven strains possessed endonuclease activities detectable in crude cell extracts. the recognition sequences and optimal reaction conditions for seven of them were determined. five enzymes were found to be isoschizomers of type ii endonucleases (ecorv, nsii, asei (2x) and saui), on ...200516701584
effect of oral administration of butyrivibrio fibrisolvens mdt-1 on experimental enterocolitis in mice.butyrivibrio fibrisolvens mdt-1, a butyrate-producing strain, was evaluated for use as a probiotic to prevent enterocolitis. oral administration of the mdt-1 strain (10(9) cfu/dose) alleviated the symptoms of colitis (including body weight loss, diarrhea, bloody stool, organic disorder, and mucosal damage) that are induced in mice drinking water that contains 3.0% dextran sulfate sodium. in addition, myeloperoxidase (mpo) activity levels in colonic tissue were reduced, suggesting that mdt-1 miti ...200616988006
diet-dependent shifts in ruminal butyrate-producing bacteria.the influence of a host's diet on butyrivibrio and pseudobutyrivibrio populations was investigated by competitive pcr. specific primers were designed and competitive pcrs developed for both groups. results (from 4 cows with different diets) suggested that high-fiber intake essentially increases the butyrivibrio amounts in the rumen, whereas high-energy food additives lead to its suppression. the pseudobutyrivibrio concentration also changed during the experiment but without any significant relat ...200617007429
expression of a beta-glucosidase gene results in increased accumulation of salicylic acid in transgenic nicotiana tabacum cv. xanthi-nc nn genotype.a beta-glucosidase gene (bgla) from butyrivibrio fibrisolvens h17c was cloned into the binary vector pga482 under the control of the 35s cauliflower mosaic virus (camv) promoter. a second construct was generated for accumulation of the bgla gene product in the vacuole of transformed tobacco plants. reverse transcription-polymerase chain reaction analysis demonstrated that the bgla gene was expressed in 71% of cytosol-targeted and 67% of vacuole-targeted transgenic tobacco t(1) plants. t(1) trans ...200717082925
a new growth medium for rapid selection and purification of clostridium proteoclasticum transposon mutants.clostridium proteoclasticum is commonly associated with the rumen microflora of pasture-fed cattle and sheep and has significant hemicellulose degradation abilities. genes involved in plant fibre breakdown are commonly identified by producing site-specific mutations. however, the genetics of c. proteoclasticum and other closely-related butyrivibrio/pseudobutyrivibrio species is not well-established. therefore random transposon mutants of c. proteoclasticum were generated by conjugation with ente ...200818346802
clostridium proteoclasticum: a ruminal bacterium that forms stearic acid from linoleic acid.the aim of this study was to identify ruminal bacteria that form stearic acid (18 : 0) from linoleic acid (cis-9,cis-12-18 : 2). one 18 : 0-producing isolate, p-18, isolated from the sheep rumen was similar in morphology and metabolic properties to 'fusocillus' spp. isolated many years ago. phylogenetic analysis based on nearly full-length 16s rrna gene sequence (>1300 bp) analysis indicated that the stearate producer was most closely related to clostridium proteoclasticum b316(t). clostridium p ...200617147764
dominance of prevotella and low abundance of classical ruminal bacterial species in the bovine rumen revealed by relative quantification real-time pcr.relative quantification real-time pcr was used to quantify several bacterial species in ruminal samples from two lactating cows, each sampled 3 h after feeding on two successive days. abundance of each target taxon was calculated as a fraction of the total 16s rrna gene copies in the samples, using taxon-specific and eubacterial domain-level primers. bacterial populations showed a clear predominance of members of the genus prevotella, which comprised 42% to 60% of the bacterial rrna gene copies ...200717235560
[inhibition of carbohydrate metabilsm enzymes by pentachlorophenol in cells of pectinolytic bacteria from gastrointestinal tract of animals and effect of clinoptilolite adsorbents on this process].changes in functional activity of specific enzyme reactions in the cells of pectinolytic bacteria from the gastrointestinal tract of animals in vitro cultivated in the medium containing pectin or glucose were studied against a background of the low dose effect of the wide spread biocide pentachlorophenol alone as well as in combination with the natural sorbents clinoptilolites. regardless of the absence of transketolase reaction in the cells of all studied strains, they metabolized highly the ab ...200617290794
the effect of polysaccharide-degrading wine yeast transformants on the efficiency of wine processing and wine flavour.commercial polysaccharase preparations are applied to winemaking to improve wine processing and quality. expression of polysaccharase-encoding genes in saccharomyces cerevisiae allows for the recombinant strains to degrade polysaccharides that traditional commercial yeast strains cannot. in this study, we constructed recombinant wine yeast strains that were able to degrade the problem-causing grape polysaccharides, glucan and xylan, by separately integrating the trichoderma reesei xyn2 xylanase ...200616644051
purification and gene sequencing of conjugated linoleic acid reductase from a gastrointestinal bacterium, butyrivibrio fibrisolvens.to characterize the cause for the lack of conjugated linoleic acid (cla) reductase (cla-r) activity in the butyrivibrio fibrisolvens mdt-5 strain that rapidly isomerizes linoleic acid (la) to cla without hydrogenation, the cla-r was purified and its gene (cla-r) sequence was determined.200717650196
influence of fish oil on ruminal biohydrogenation of c18 unsaturated fatty acids.dietary cis-9, trans-11-conjugated linoleic acid (cla) is generally thought to be beneficial for human health. fish oil added to ruminant diets increases the cla concentration of milk and meat, an increase thought to arise from alterations in ruminal biohydrogenation of unsaturated fatty acids. to investigate the mechanism for this effect, in vitro incubations were carried out with ruminal digesta and the main biohydrogenating ruminal bacterium, butyrivibrio fibrisolvens. linoleic acid (la) or a ...200616768845
novel rumen bacterial diversity in two geographically separated sub-species of reindeer.svalbard reindeer (rangifer tarandus platyrhynchus) live under austere nutritional conditions on the high-arctic archipelago of svalbard, while semi-domesticated norwegian reindeer (r. tarandus tarandus) migrate between lush coastal summer pastures and inland winter pastures with lichens on mainland norway. svalbard reindeer are known to have high rumen concentrations of cellulolytic bacteria, ranging from 15% of the viable population in summer to 35% in winter, compared to only 2.5% in norwegia ...200717473904
isomers of conjugated linoleic acids are synthesized via different mechanisms in ruminal digesta and bacteria.digesta samples from the ovine rumen and pure ruminal bacteria were incubated with linoleic acid (la) in deuterium oxide-containing buffer to investigate the mechanisms of the formation of conjugated linoleic acids (clas). rumenic acid (ra; cis-9,trans-11-18:2), trans-9,trans-11-18:2, and trans-10,cis-12-18:2 were the major cla intermediates formed from la in ruminal digesta, with traces of trans-9,cis-11-18:2, cis-9,cis-11-18:2, and cis-10,cis-12-18:2. mass spectrometry indicated an increase in ...200717644775
oral administration of butyrivibrio fibrisolvens, a butyrate-producing bacterium, decreases the formation of aberrant crypt foci in the colon and rectum of mice.butyrivibrio fibrisolvens, a butyrate-producing ruminal bacterium, was evaluated for use as a probiotic to prevent colorectal cancer. oral administration to jcl:icr mice of a new strain of b. fibrisolvens (mdt-1) that produces butyrate at a high rate (10(9) cfu/dose) increased the rate of butyrate production by fecal microbes, suggesting that mdt-1 can grow in the gut. the number of colorectal aberrant crypt foci (acf), putative preneoplastic lesions induced by 1,2-dimethylhydrazine, was reduced ...200516317136
isolation and characterization of putative pseudobutyrivibrio ruminis promoters.novel plasmids were constructed for the analysis of dna fragments from the rumen bacterium pseudobutyrivibrio ruminis. five previously unidentified promoters were characterized using a novel primer extension method to identify transcription start sites. the genes downstream of these promoters were not identified, and their activity in expression of genomic traits in wild-type p. ruminis remains putative. comparison with promoters from this and closely related species revealed a consensus sequenc ...200717768250
effect of oral administration of butyrivibrio fibrisolvens mdt-1, a gastrointestinal bacterium, on 3-methylcholanthrene-induced tumor in mice.butyrivibrio fibrisolvens mdt-1 was evaluated for use as a probiotic to prevent tumor formation. oral administration of mdt-1 (10(9) cfu/dose, 3 times a wk for 15 wk) delayed the onset of tumors induced by 3-methylcholanthrene and also reduced tumor incidence in mice. furthermore, the numbers of natural killer (nk) and nkt cells in the spleen increased markedly in response to mdt-1 administration. increased numbers of nk and nkt cells may contribute to the alleviation of carcinogenesis by mdt-1 ...200717927507
genetic features of circular bacteriocins produced by gram-positive bacteria.this review highlights the main genetic features of circular bacteriocins, which require the co-ordinated expression of several genetic determinants. in general terms, it has been demonstrated that the expression of such structural genes must be combined with the activity of proteins involved in maturation (cleavage/circularization) and secretion outside the cell via different transporter systems, as well as multifaceted immunity mechanisms essential to ensuring the bacteria's self-protection ag ...200818034824
molecular analysis of tet(w) gene-mediated tetracycline resistance in dominant intestinal bifidobacterium species from healthy humans.tet(w) was found responsible for tetracycline resistance (mics, 4 to > or =32 microg ml(-1)) in dominant bifidobacterial species from the gastrointestinal tracts of healthy humans. the gene from bifidobacterium longum h66 proved to be identical over a 2.6-kbp region to the recently described tet(w) determinant of butyrivibrio fibrisolvens.200616936047
metabolism of polyunsaturated fatty acids and their toxicity to the microflora of the rumen.ruminal microorganisms hydrogenate polyunsaturated fatty acids (pufa) present in forages and thereby restrict the availability of health-promoting pufa in meat and milk. the aim of this study was to investigate pufa metabolism and the influence of pufa on members of the ruminal microflora. eleven of 26 predominant species of ruminal bacteria metabolised linoleic acid (la; cis-9,cis-12-18:2) substantially. the most common product was vaccenic acid (trans-11-18:1), produced by species related to b ...200717072533
augmentation of vaccenate production and suppression of vaccenate biohydrogenation in cultures of mixed ruminal microbes.to increase ruminal outflow of trans-vaccenic acid (t-va), a new strain of butyrivibrio fibrisolvens (mdt-10) was isolated that has a great ability to hydrogenate linoleic acid (la) to t-va. when strain mdt-10 was added to the batch cultures of mixed ruminal microbes (1% of the total number of viable ruminal bacteria), la conversion to t-va increased greatly; after 3 h, t-va levels were > 4-fold higher than the control. by 10 h, all of the t-va was hydrogenated to stearic acid. however, when a n ...200616507700
adaptation of adhesion test using caco-2 cells for anaerobic bacterium pseudobutyrivibrio xylanivorans, a probiotic candidate.pseudobutyrivibrio xylanivorans strain mz5(t), an anaerobic bacterium (originating from the rumen of a holstein-friesian cow), has some attributes that make it a possible probiotic strain (very active hydrolases, bacteriocin and conjugated linoleic acid production). for the estimation of its adhesion ability, the adhesion test on caco-2 cells was introduced and adapted. the adhesion was performed in an anaerobic glove box in standard 24-well plates at neutral ph for 30 min. the best method for s ...200718062185
cell-associated alpha-amylases of butyrate-producing firmicute bacteria from the human colon.selected butyrate-producing bacteria from the human colon that are related to roseburia spp. and butyrivibrio fibrisolvens showed a good ability to utilize a variety of starches for growth when compared with the gram-negative amylolytic anaerobe bacteroides thetaiotaomicron. a major cell-associated amylase of high molecular mass (140-210 kda) was detected in each strain by sds-page zymogram analysis, and genes corresponding to these enzymes were analysed for two representative strains. amy13b fr ...200617074899
relation between phylogenetic position, lipid metabolism and butyrate production by different butyrivibrio-like bacteria from the rumen.the butyrivibrio group comprises butyrivibrio fibrisolvens and related gram-positive bacteria isolated mainly from the rumen of cattle and sheep. the aim of this study was to investigate phenotypic characteristics that discriminate between different phylotypes. the phylogenetic position, derived from 16s rdna sequence data, of 45 isolates from different species and different countries was compared with their fermentation products, mechanism of butyrate formation, lipid metabolism and sensitivity ...200717077990
the characterization of lactic acid producing bacteria from the rumen of dairy cattle grazing on improved pasture supplemented with wheat and barley grain.to identify and characterize the major lactic acid bacteria in the rumen of dairy cattle grazing improved pasture of rye grass and white clover and receiving a maize silage and grain supplement with and without virginiamycin.200818217928
biochemistry of pufa double bond isomerases producing conjugated linoleic acid.the biotransformation of linoleic acid (la) into conjugated linoleic acid (cla) by microorganisms is a potentially useful industrial process. in most cases, however, the identities of proteins involved and the details of enzymatic activity regulation are far from clear. here we summarize available data on the reaction mechanisms of cla-producing enzymes characterized until now, from butyrivibrio fibrisolvens, lactobacillus acidophilus, ptilota filicina, and propionibacterium acnes. a general fea ...200818655062
diversity of the resident microbiota in a thermophilic municipal biogas plant.biogas plants continuously convert biological wastes mainly into a mixture of methane, co2 and h2o-a conversion that is carried out by a consortium of bacteria and archaea. especially in the municipal plants dedicated towards waste treatment, the reactor feed may vary considerably, exposing the resident microbiota to a changing variety of substrates. to evaluate how and if such changes influence the microbiology, an established biogas plant (6,600 m3, up to 600 m3 biogas per h) was followed over ...200818820906
biotransformation of 2,4,6-trinitrotoluene by pure culture ruminal bacteria.twenty-one ruminal bacteria species were tested for their ability to degrade 2,4,6-trinitrotoluene (tnt) within 24 h. butyrivibrio fibrisolvens, fibrobacter succinogenes, lactobacillus vitulinus, selenomonas ruminantium, streptococcus caprinus, and succinivibrio dextrinosolvens were able to completely degrade 100 mg/l tnt, with <5% of the original tnt recovered as diaminonitrotoluene metabolites. eubacterium ruminantium, lactobacillus ruminis, ruminobacter amylophilus, streptococcus bovis, and w ...200918839246
effect of monensin feeding and withdrawal on populations of individual bacterial species in the rumen of lactating dairy cows fed high-starch rations.real-time polymerase chain reaction (pcr) was used to quantify 16 procaryotic taxa in the rumina of two lactating dairy cows following supply and subsequent withdrawal of the feed additive monensin (13.9 mg/kg of diet dry matter) in a high-starch, silage-based ration. pcr was conducted on dna from rumen samples collected 6 h post feeding on two successive days before monensin supplementation, after 30 days of monensin supplementation, and at six weekly intervals after monensin withdrawal. mean v ...200818535825
increased expression of a molecular chaperone groel in response to unsaturated fatty acids by the biohydrogenating ruminal bacterium, butyrivibrio fibrisolvens.butyrivibrio fibrisolvens is the most active bacterial species in the biohydrogenation of polyunsaturated fatty acids (pufa) in the rumen. it needs to remove the unsaturated bonds in order to detoxify the pufa to enable the growth of the bacterium. here, we investigated the response of cell membrane-associated proteins in b. fibrisolvens to growth in the presence of pufa. numerous changes were observed in the cell membrane-associated proteome. one of the main modifications occurring when the 18: ...200616923082
evaluation and characterization of bacterial metabolic dynamics with a novel profiling technique, real-time metabolotyping.environmental processes in ecosystems are dynamically altered by several metabolic responses in microorganisms, including intracellular sensing and pumping, battle for survival, and supply of or competition for nutrients. notably, intestinal bacteria maintain homeostatic balance in mammals via multiple dynamic biochemical reactions to produce several metabolites from undigested food, and those metabolites exert various effects on mammalian cells in a time-dependent manner. we have established a ...200919287504
sucrose phosphorylase of the rumen bacterium pseudobutyrivibrio ruminis strain a.to verify the taxonomic affiliation of bacterium butyrivibrio fibrisolvens strain a from our collection and to characterize its enzyme(s) responsible for digestion of sucrose.200919320946
investigating unsaturated fat, monensin, or bromoethanesulfonate in continuous cultures retaining ruminal protozoa. ii. interaction of treatment and presence of protozoa on prokaryotic communities.increasing the consistency of responses to reduce emissions of ruminal methane and nitrogenous wastes into the environment using microbial inhibitors requires an accurate assessment of microbial community profiles. in addition to direct inhibition of methanogens by feed additives, protozoa are often targeted for inhibition because their close physical association with endo- and ectosymbionts stimulates methanogenesis in the rumen. in this study, we first modified a continuous culture system to m ...200919620670
effect of ph and level of concentrate in the diet on the production of biohydrogenation intermediates in a dual-flow continuous culture.milk fat depression in cows fed high-grain diets has been related to an increase in the concentration of trans-10 c(18:1) and trans-10,cis-12 conjugated linoleic acid (cla) in milk. these fatty acids (fa) are produced as a result of the alteration in rumen biohydrogenation of dietary unsaturated fa. because a reduction in ruminal ph is usually observed when high-concentrate diets are fed, the main cause that determines the alteration in the biohydrogenation pathways is not clear. the effect of p ...200919700707
metabolism of conjugated linoleic acids and 18 : 1 fatty acids by ruminal bacteria: products and mechanisms.cultures of ruminal bacteria known to metabolize unsaturated fatty acids were grown in medium containing 50 microg ml(-1) of geometric and positional isomers of conjugated linoleic acid (cla) or 18 : 1 fatty acids and 37.4 % deuterium oxide to investigate the mechanisms responsible for fatty acid metabolism. butyrivibrio fibrisolvens jw11 converted cis-9,trans-11-18 : 2 and trans-9,trans-11-18 : 2 to trans-11-18 : 1 as the main product, labelled at c-9, and metabolized trans-10,cis-12-18 : 2 to ...201019926650
the heterologous expression of polysaccharidase-encoding genes with oenological relevance in saccharomyces cerevisiae.the main objective of this study was to develop polysaccharide-degrading wine strains of saccharomyces cerevisiae, which are able to improve aspects of wine processing and clarification, as well as colour extraction and stabilization during winemaking.200718045408
molecular monitoring and isolation of previously uncultured bacterial strains from the sheep rumen.to estimate the contribution of uncultured bacterial groups to fiber degradation, we attempted to retrieve both ecological and functional information on uncultured groups in the rumen. among previously reported uncultured bacteria, fiber-associated groups u2 and u3, belonging to the low-gc gram-positive bacterial group, were targeted. pcr primers and fluorescence in situ hybridization (fish) probe targeting 16s rrna genes or rrna were designed and used to monitor the distribution of targets. the ...201020118379
mechanism of conjugated linoleic acid and vaccenic acid formation in human faecal suspensions and pure cultures of intestinal bacteria.faecal bacteria from four human donors and six species of human intestinal bacteria known to metabolize linoleic acid (la) were incubated with la in deuterium oxide-enriched medium to investigate the mechanisms of conjugated linoleic acid (cla) and vaccenic acid (va) formation. the main cla products in faecal suspensions, rumenic acid (cis-9,trans-11-cla; ra) and trans-9,trans-11-cla, were labelled at c-13, as were other 9,11 geometric isomers. traces of trans-10,cis-12-cla formed were labelled ...200919118369
the use of pcr for the identification and characterisation of bacteriocin genes from bacterial strains isolated from rumen or caecal contents of cattle and sheep.pcr primers were designed to amplify the gene that encodes bovicin 255 from streptococcus gallolyticus lrc0255 and the bacteriocin genes from butyrivibrio fibrisolvens strains ar10 and or79a (bvid and bvi79a) in order to screen for their incidence in rumen and caecal b. fibrisolvens and streptococcus bovis-like isolates from new zealand and north american ruminants. none of the b. fibrisolvens-like strains (n=34) isolated from new zealand or north america had the genes encoding for butyrivibrioc ...200419712403
structural and functional characterization of a promiscuous feruloyl esterase (est1e) from the rumen bacterium butyrivibrio proteoclasticus.the release of polysaccharide from the plant cell wall is a key process to release the stored energy from plant biomass. within the ruminant digestive system, a host of commensal microorganisms speed the breakdown of plant cell matter releasing fermentable sugars. the presence of phenolic compounds, most notably ferulic acid (fa), esterified within the cell wall is thought to pose a significant impediment to the degradation of the plant cell wall. the structure of a fa esterase from the ruminant ...201020058325
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