PMID(sorted ascending)
enzymology of butyrate formation by butyrivibrio fibrisolvens.butyrivibrio fibrisolvens is a major butyrate-forming species in the bovine and ovine rumen. the enzymology of butyrate formation from pyruvate was investigated in cell-free extracts of b. fibrisolvens d1. pyruvate owas oxidized to acetylcoenzyme a (coa) in the presence of and benzyl viologen or flavin nucleotides. the bacterium uses thiolase, beta-hydroxybutyryl-coa dehydrogenase, crotonase, and crotonyl-coa reductase to form butyryl-coa from acetyl-coa. reduction of acetoacetyl-coa to b ...197935524
glycerol teichoic acid as an antigenic determinant in a gram-negative bacterium butyrivibrio antigenic determinant isolated from a strain of the gram-negative bacterium butyrivibrio fibrisolvens reacted with specific antisera to the polyglycerophosphate backbone of membrane teichoic acids of lactobacilli. it gave a reaction of identity with membrane glycerol lipoteichoic acid and glycerol teichoic acid preparations from lactobacilli, and with phenol extracts of other gram-positive bacteria. the antigen-antibody reactions was strongly inhibited by glycerol-phosphoryl-glycerol-phosphor ...197550403
biohydrogenation of unsaturated fatty acids. presence of dithionite and an endogenous electron donor in butyrivibrio fibrisolvens.two oxygen-consuming substances were isolated from cell-free extracts of the rumen anaerobe, butyrivibrio fibrisolvens. the major fraction comprising 97% of the total activity was characterized as a three-component mixture of glucose, maltose, and dithionite. the minor activity fraction contained an electron donor for the reduction of cis-9,trans-11-octadecadienoate to trans-11-octadecenoate. after oxidation, the electron donor could be reduced by the dithionite, thereby accounting for the previ ...1979438161
some effects of uncouplers and inhibitors on growth and electron transport in rumen bacteria.uncouplers and inhibitors of electron transport affected growth and electron transport of rumen bacteria in various ways. selenomonas ruminantium was not affected by inhibitor and uncoupler concentrations which affected growth and electron transport of bacteroides ruminicola, b. succinogenes, and butyrivibrio fibrisolvens. inhibitors, when active, led to accumulation of reduced electron carriers before the site of action, but differences were found among organisms in the site of action of these ...1979457609
characteristics of a lipolytic and fatty acid-requiring butyrivibrio sp. isolated from the ovine rumen.a naturally occurring fatty acid-requiring butyrivibrio sp. (strain s2), isolated from the ovine rumen, deacylates plant galactolipids, phospholipids and sulpholipids to obtain sufficient fatty acid for growth. growth in vitro was promoted by adding to the growth medium a single straight-chain saturated fatty acid (c13 to c18) or vaccenic acid. palmitoleic and oleic acids also supported growth but gave lengthy lag phases probably due to their toxicity. linolenic and linoleic acids supported good ...1979479833
a new series of long-chain dicarboxylic acids with vicinal dimethyl branching found as major components of the lipids of butyrivibrio spp.1. some members of the genus butyrivibrio, including a general fatty acid auxotroph (strain s2), contain as a major part of their complex lipids a high-molecular-weight component that is probably formed by the union of two fatty acid chains [hazlewood & dawson (1979) j. gen. microbiol. 112, 15--27]. 2. proton and 13c n.m.r. and i.r. and mass spectroscopy were used to examine a homologous series of these moieties and, in addition, the hydrocarbon derivative of one homologue and several synthetic ...1979540040
studies on some characteristics of hydrogen production by cell-free extracts of rumen anaerobic bacteria.hydrogen production was studied in the following rumen anaerobes: bacteroides clostridiiformis, butyrivibrio fibrisolvens, enbacterium limosum, fusobacterium necrophorum, megasphaera elsdenii, ruminococcus albus, and ruminococcus flavefaciens. clostridium pasteurianum and escherichia coli were included for comparative purposes. hydrogen production from dithionite, dithionite-reduced methyl viologen, pyruvate, and formate was determined. all species tested produced hydrogen from dithionite-reduce ...1977558042
effects of heavy metals and other trace elements on the fermentative activity of the rumen microflora and growth of functionally important rumen bacteria.the inhibitory effects of high concentrations of essential and non-essential trace elements were tested on the rumen microflora using the rate of fermentation in vitro as the assay. the elements (and the concentration causing 50% inhibition) in decreasing order of toxicity were hg2+ (20 microgram/ml), cu2+ (21 microgram/ml), cr6+ (70 microgram/ml), se4+ (73 microgram/ml), ni2+ (160 microgram/ml), cd2+ (175 microgram/ml), as3+ (304 microgram/ml) and as5+ (1610 microgram/ml). the elements tested t ...1978565671
production of branched-chain volatile fatty acids by certain anaerobic production of isobutyric acid, isovaleric acid, and 2-methylbutyric acid by cultures of bacteroides ruminicola and megasphaera elsdenii on media that contained trypticase or casein hydrolysate continued (up to 5 days) after growth had ceased. only trace quantities of these acids were produced in a medium that contained a mixture of amino acids that did not include the branched-chain amino acids. m. elsdenii produced increased quantities of the branched-chain fatty acids in a medium that cont ...1978566082
the role of carbonate in the metabolism of glucose by butyrivibrio fibrisolvens.the amount of na2co3 added to semi-synthetic medium determined the length of the lag phase, the growth rate and the dry weight of three strains of butyrivibrio fibrisolvens (wv1, nor37, b835). with increasing co3(2-) concentration the molar growth yield of bacteria, from glucosewas increased and, of the fermentation products, formate increased more than the other acids. co3(2-)-limited cultures of strain wv1 (group 2 butyrivibrio) and strain nor37 (troup 1 butyrivibrio) incorporated 14co3(2-) in ...1978641526
isolation of lipoteichoic acids from butyrivibrio fibrisolvens.lipoteichoic acid (lta) and deacylated lipoteichoic acid have been isolated from the bovine-rumen gram-negative anaerobe butyrivibrio fibrisolvens by phenol extraction. lipoteichoic acid (21.8 mumol phosphorus/g cells) consisted of a conventional 1, 3-phosphodiester-linked chain of glycerol phosphate units joined covalently to a glycolipid. it was not substituted with glycosyl or d-alalyl ester groups. deacylated lipoteichoic acid (57.5 mumol phosphorus/g cells) was similar in constitution but l ...1976819620
ultrastructure of butyrivibrio fibrisolvens: a gram-positive bacterium.the cells of bacteria of the genus butyrivibrio are universally described as being gram negative, and they produce an unequivocal gram-negative reaction in the standard staining procedure. however, their cell walls contain derivatives of teichoic acid, which are characteristic of gram-positive cells. in this study, the cell walls of two representative strains of butyrivibrio were of the gram-positive morphological type, as seen by electron microscopy, but they were very thin (12 to 18 nm). the t ...1977845122
glucose-1-phosphate as a selective substrate for enumeration of bacteroides species in the rumen.when glucose-1-phosphate was used as the only added energy source in a selective roll tube medium, colony counts for rumen contents ranged from 17.8 to 84.8% of the total culturable count. percentages were highest in rumen contents from sheep fed high-concentrate rations. from a total of 73 cultures isolated from glucose-1-phosphate roll rubes, only 15.1% were presumptively identified as bacteroides species. strains presumptively identified as butyrivibrio, selenomonas, treponema, streptococcus ...1977869544
activation of nad-dependent lactate dehydrogenase in butyrivibrio fibrisolvens by fructose 1,6-diphosphate. 1977874457
characterization of the predominant bacteria occurring in the rumen of goats (capra hircus).a total of 44 strains of bacteria were isolated from rumen contents of the goat. based on morphology, gram stain, anaerobiosis, motility, and fermentation end products, they were grouped into 11 different types. for each type, all or representative strains were characterized in detail. the type, number of strains characterized over total number of strains, and identification were as follows: type 1, 6/21, atypical butyrivibrio fibriosolvens; type 2, 6/9, atypical butyrivibrio fibrisolvens; type ...1977879766
urease assay and urease-producing species of anaerobes in the bovine rumen and human feces.a growth medium and test were developed for rapid detection of urease in fermentative anaerobic bacteria. using nonselective rumen fluid roll-tube agar medium and the new test, it was confirmed that peptostreptococcus productus is often the most numerous urease-forming species in human feces. also, some fecal strains of ruminococcus albus, clostridium innocuum, and clostridium beijerinckii produced urease. single strains of fusobacterium prausnitzii, coprococcus catus, and streptococcus mitis th ...1977879770
cultural factors influencing the utilization or production of acetate by butyrivibrio fibrisolvens.utilization of acetate by four strains of butyrivibrio fibrisolvens was influenced by the composition of their growth medium. growth-limiting glucose concentrations, low availability of co2 and the presence of sodium lactate all stimulated acetate uptake by three strains. the type strain, d1, utilized acetate if the concentration of acetate added to the medium was at least 15 mumol ml-1. in batch culture, all strains produced acetate before entering a phase of acetate uptake. continuous-culture ...1976985851
novel lipids of butyrivibrio spp.(1) an analysis has been conducted of the lipids present in three obligately anaerobic bacteria isolated from the ovine rumen belonging to the genus butyrivibrio. two of these organisms are rich in phospholipase (a1 + a2) activity, and appear to be different strains of the species fibrisolvens. (2) the only n-containing lipids comprise n-acyl-phosphatidylethanolamine occurring as a minor component in all organisms and a new lipid, diglyceride galactosylphosphorylethanolamine in one of these. (3) ...1976991380
some aspects of the metabolism of butyrivibrio fibrisolvens.the growth responses of an acetate-utilizing isolate of butyrivibrio fibrisolvens to co2, acetate and pyruvate were determined using a chemically-defined medium. carbon dioxide was essential for growth and both acetate and pyruvate increased growth. 14c from [i-14c]pyruvate appeared predominantly in formate and lactate. these results, together with those obtained with enzyme preparations, indicated pyruvate synthase, pyruvate-co2 exchange and pyruvate formate lyase to be active.1976993781
intermolecular transacylation of phosphatidylethanolamine by a butyrivibrio sp.1. washed cells and supernatant from a culture of a butyrivibrio sp. carry out the intermolecular transacylation reaction 2 phosphatidylethanolamine leads to n-acylphosphatidyl-ethanolamine+lysophosphatidylethanolamine. 2. washed cells can catalyse the intramolecular transacylation of n-(acyl)glycerylphosphorylethanolamine to lysophosphatidylethanolamine; the culture supernatant is largely devoid of activity.19751212204
the isomerization of 2,5- and 9,12-octadecadienoic acids by an extract of butyrivibrio fibrisolvens.a cell-free particulate preparation from butyrivibrio fibrisolvens was used to study the relative rates of isomerization of all cis,cis-methylene-interrupted isomers of octadecadienoic acid. only two isomers were found to be substrates, the 9,12-isomer was isomerized at 41 +/- 4 mumol/min per mg protein, and the 2,5-isomer at 11 +/- 1 mumol/min per mg. the product of the isomerization of the 2,5-isomer had an ultraviolet absorption maximum at 233 nm indicating that it was the 3,5-isomer. the iso ...19761252494
a phospholipid-deacylating system of bacteria active in a frozen medium.a phosphatidylcholine-deacylating system present in a butyrivibrio species (probably fibrisolvens) shows appreciable activity at low temperatures with a maximum hydrolysis rate at--10 degrees c. 2. the rate at--10 degrees c is higher than at 39 degrees c unless the system at the latter temperature is stimulated by adding oleic acid or sodium dodecyl sulphate. 3. the low-temperature phospholipase activity has an absolute requirement for thiol reagents, e.g. cysteine, dithiothreitol or mercaptoeth ...19761259714
biohydrogenation of unsaturated fatty acids. hydrogenation by cell-free preparations of butyrivibrio fibrisolvens.hydrogenation of cis-9,trans-11-octadecadienoic acid to yield trans-11-octadecenoic acid by cell-free preparations of butyrivibrio fibrisolvens has been obtained under strictly anaerobic conditions. reduced methyl viologen, nadh, and an endogenous electron donor each can serve as a reductant. inhibition studies and gel filtration patterns reveal the presence of at least two hydrogenation systems, one of which is coupled through a flavin, possibly fmn. although the enzymes comprising the biohydro ...19761262324
the gene encoding the cellulase (avicelase) cel1 from streptomyces reticuli and analysis of protein domains.streptomyces reticuli produces an unusual cellulase (avicelase), with an apparent molecular weight of 82 kda, which is solely sufficient to degrade crystalline cellulose. during cultivation the processing of the avicelase to a truncated enzyme (42 kda) and an inactive protein (40 kda) correlated with the occurrence of an extracellular protease. after its purification this 36 kda protease cleaved the s. reticuli avicelase in vitro in the same manner. using antibodies raised against the avicelase ...19921282194
dap-decarboxylase activity and lysine production by rumen bacteria.the last step of pathway of lysine biosynthesis by rumen bacteria was tested. the first measurements of dap-decarboxylase activity and of lysine production by megasphera elsdenii, selenomonas ruminantium, clostridium spp., butyrivibrio fibrisolvens and bacteroides succinogenes as well as the first attempts to increase the lysine production by ruminal streptococci by mutation are described. the highest values were measured in selenomonas ruminantium (dap-decarboxylase activity = 146 micrograms da ...19921295484
cloning and expression of an amylase gene from streptococcus bovis in escherichia amylase gene was identified in a streptococcus bovis 033 lambda gtwes lambda b genomic library. using a starch overlay and a congo red-iodine staining procedure, amylase positive clones could be identified by zones of clearing. ten amylase positive clones were identified using this procedure. the clone chosen for further study, lambda sba105, contained an insert of approximately 7.5 kb. the insert was mapped, and subcloning localized the amylase gene to a region of approximately 3.1 kb. cloni ...19921380794
phylogenetic and chemotaxonomic characterization of acidaminococcus fermentans.the phylogenetic position of acidaminococcus fermentans was determined by comparative sequence analysis of the 16s rrna. this gram-negative bacterium is a member of the sporomusa cluster that is defined by other gram-negative bacteria, i.e. sporomusa, megasphaera, selenomonas, butyrivibrio, pectinatus, and zymophilus. the branching point of this group within the radiation of gram-positive bacteria of the clostridium/bacillus subphylum and adjacent to peptococcus niger could be confirmed. chemota ...19921385264
interaction of ruminal bacteria in the production and utilization of maltooligosaccharides from starch.the degradation and utilization of starch by three amylolytic and one nonamylolytic species of ruminal bacteria were studied. pure cultures of streptococcus bovis jb1, butyrivibrio fibrisolvens 49, and bacteroides ruminicola d31d rapidly hydrolyzed starch and maltooligosaccharides accumulated. the major starch hydrolytic products detected in s. bovis cultures were glucose, maltose, maltotriose, and maltotetraose. in addition to these oligosaccharides, b. fibrisolvens cultures produced maltopenta ...19921539992
conjugal transfer of tn916, tn916 delta e, and pam beta 1 from enterococcus faecalis to butyrivibrio fibrisolvens strains.anaerobic filter matings of butyrivibrio fibrisolvens h17c, cf3, d1, or gs113, representing different dna relatedness groups, were done with enterococcus faecalis cg110, which contains chromosomally inserted tn916. tetracycline-resistant transconjugants were obtained with each mating pair at average frequencies of 4.4 x 10(-6) (per recipient) and 5.2 x 10(-6) (per donor). the transfer frequencies of tn916 into b. fibrisolvens varied 5- to 10-fold with mating time, strain, and growth stage. by us ...19911662939
introduction of tn916 and pam beta 1 into streptococcus bovis jb1 by conjugation.the transposon tn916 and self-mobilizing plasmid pam beta 1 were conjugated from enterococcus faecalis to the ruminal bacterium streptococcus bovis jb1. transconjugants were identified by resistance to tetracycline (tn916) or erythromycin (pam beta 1) and by southern hybridization analyses. transfer frequencies were 7.0 x 10(-6) and 1.0 x 10(-6) per recipient cell for tn916 and pam beta 1, respectively. the transconjugants jb1/tn916 and jb1/pam beta 1 were used as donors for matings with e. faec ...19911662940
mechanism of gram variability in select bacteria.gram stains were performed on strains of actinomyces bovis, actinomyces viscosus, arthrobacter globiformis, bacillus brevis, butyrivibrio fibrisolvens, clostridium tetani, clostridium thermosaccharolyticum, corynebacterium parvum, mycobacterium phlei, and propionibacterium acnes, using a modified gram regimen that allowed the staining process to be observed by electron microscopy (j. a. davies, g. k. anderson, t. j. beveridge, and h. c. clark, j. bacteriol. 156:837-845, 1983). furthermore, since ...19901689718
antigenic nature of the chloride-stimulated cellobiosidase and other cellulases of fibrobacter succinogenes subsp. succinogenes s85 and related fresh isolates.polyclonal and monoclonal antibodies to the cl-stimulated cellobiosidase of fibrobacter succinogenes subsp. succinogenes s85 reacted with numerous proteins of both higher and lower molecular weights from f. succinogenes subsp. succinogenes s85, but not with escherichia coli proteins, and only one protein each from butyrivibrio fibrisolvens and ruminococcus albus. different profiles were observed for western blots (immunoblots) of peptide digests of both the purified enzyme from f. succinogenes a ...19901692677
a survey of peptidase activity in rumen bacteria.twenty-nine strains of 14 species of rumen bacteria were screened for their ability to hydrolyse ala2, ala5, glyarg-4-methoxy-2-naphthylamide (glyarg-mna) and leu-mna. several species, notably megasphaera elsdenii, were active against ala2, and a smaller number, including bacteroides ruminicola, butyrivibrio fibrisolvens, ruminococcus flavefaciens, lachnospira multipara and ruminobacter amylophilus, broke down ala5. streptococcus bovis had an exceptionally high leucine arylamidase activity. howe ...19911748877
an analysis of the extracellular xylanases and cellulases of butyrivibrio fibrisolvens h17c.the extracellular xylanase and cellulase components of butyrivibrio fibrisolvens h17c were investigated. two major peaks of enzyme activity were eluted by hydroxylapatite chromatography and designated complex a (ca), having cellulase activity, and complex b (cb) having predominantly xylanase activity but with some activity on carboxymethyl cellulose (cmc). cb was further purified on a de-52 column and subjected to gel filtration. the xylanase and cmcase activities eluted in a single peak with an ...19911778443
some chemical and physical properties of extracellular polysaccharides produced by butyrivibrio fibrisolvens strains.most strains of butyrivibrio fibrisolvens are known to produce extracellular polysaccharides (eps). however, the rheological and functional properties of these eps have not been determined. initially, 26 strains of butyrivibrio were screened for ep yield and apparent viscosities of cell-free supernatants. yields ranged from less than 1.0 to 16.3 mg per 100 mg of glucose added to the culture. viscosities ranged from 0.71 to 5.44 mpa.s. five strains (cf2d, cf3, cf3a, ce51, and h10b) were chosen fo ...19911892390
sequencing and expression of the butyrivibrio fibrisolvens xylb gene encoding a novel bifunctional protein with beta-d-xylosidase and alpha-l-arabinofuranosidase activities.a single gene (xylb) encoding both beta-d-xylosidase (ec and alpha-l-arabinofuranosidase (ec activities was identified and sequenced from the ruminal bacterium butyrivibrio fibrisolvens. the xylb gene consists of a 1.551-bp open reading frame (orf) encoding 517 amino acids. a subclone containing a 1.843-bp dna fragment retained both enzymatic activities. insertion of a 10-bp noti linker into the ecorv site within the central region of this orf abolished both activities. sodiu ...19911905520
cloning, sequencing and expression of a gene encoding a 73 kda xylanase enzyme from the rumen anaerobe butyrivibrio fibrisolvens h17c.the cloning, expression and nucleotide sequence of a 3 kb dna segment on pls206 containing a xylanase gene (xynb) from butyrivibrio fibrisolvens h17c was investigated. the open reading frame (orf) of 1905 bp encoded a xylanase of 635 amino acid residues (mr 73156). at least 850 bp at the 3' end of the gene could be deleted without loss of xylanase activity. the deduced amino acid sequence was confirmed by purifying the enzyme and subjecting it to n-terminal amino acid sequence analysis. in esche ...19911909424
characterization of the butyrivibrio fibrisolvens glgb gene, which encodes a glycogen-branching enzyme with starch-clearing activity.a butyrivibrio fibrisolvens h17c glgb gene, was isolated by direct selection for colonies that produced clearing on starch azure plates. the gene was expressed in escherichia coli from its own promoter. the glgb gene consisted of an open reading frame of 1,920 bp encoding a protein of 639 amino acids (calculated mr, 73,875) with 46 to 50% sequence homology with other branching enzymes. a limited region of 12 amino acids showed sequence similarity to amylases and glucanotransferases. the b. fibri ...19911938880
the cellodextrinase from pseudomonas fluorescens subsp. cellulosa consists of multiple functional domains.a genomic library of pseudomonas fluorescens subsp. cellulosa dna was constructed in puc18 and escherichia coli recombinants expressing 4-methylumbelliferyl beta-d-cellobioside-hydrolysing activity (mucase) were isolated. enzyme produced by mucase-positive clones did not hydrolyse either cellobiose or cellotriose but converted cellotetraose into cellobiose and cleaved cellopentaose and cellohexaose, producing a mixture of cellobiose and cellotriose. there was no activity against cm-cellulose, in ...19911953673
the hydrolysis of lucerne cell-wall monosaccharide components by monocultures or pair combinations of defined ruminal bacteria.the defined ruminal bacterial strains fibrobacter succinogenes s85, ruminococcus flavefaciens fd1, ruminococcus albus 7, butyrivibrio fibrisolvens d1, and bacteroides ruminicola ga33 were grown, in monocultures or as combinations of pair strains, on isolated lucerne cell-walls (cw) as the sole carbohydrate substrate. fibrobacter succinogenes s85 was the dominant strain determining extent of cw hydrolysis in all combinations with s85. the hydrolysis of cellulose, xylan, hemicellulose side-sugars, ...19912030098
cloning, nucleotide sequence, and enzymatic characterization of an alpha-amylase from the ruminal bacterium butyrivibrio fibrisolvens h17c.a butyrivibrio fibrisolvens amylase gene was cloned and expressed by using its own promoter on the recombinant plasmid pbamy100 in escherichia coli. the amylase gene consisted of an open reading frame of 2,931 bp encoding a protein of 976 amino acids with a calculated mr of 106,964. in e. coli(pbamy100), more than 86% of the active amylase was located in the periplasm, and tnphoa fusion experiments showed that the enzyme had a functional signal peptide. the b. fibrisolvens amylase is a calcium m ...19912061294
preservation of ruminal bacterium capsules by using lysine in the electron microscopy fixative.ruminal bacteria from axenic cultures of ruminococcus flavefaciens fd1, butyrivibrio fibrisolvens 49, and bacterial types from the ruminal ecosystem that were fixed with 50 mm lysine (l-lysine hydrochloride) added to glutaraldehyde had better-preserved capsules and extracellular material than bacteria fixed without lysine.19902125818
cloning, sequencing, and expression of a xylanase gene from the anaerobic ruminal bacterium butyrivibrio fibrisolvens.a gene coding for xylanase activity, xyna, from the anaerobic ruminal bacterium butyrivibrio fibrisolvens 49 was cloned into escherichia coli jm83 by using plasmid puc19. the gene was located on a 2.3-kilobase (kb) dna insert composed of two adjacent ecori fragments of 1.65 and 0.65 kb. expression of xylanase activity required parts of both ecori segments. in e. coli, the cloned xylanase enzyme was not secreted and remained cell associated. the enzyme exhibited no arabinosidase, cellulase, alpha ...19902198249
azoreductase activity of anaerobic bacteria isolated from human intestinal microflora.a plate assay was developed for the detection of anaerobic bacteria that produce azoreductases. with this plate assay, 10 strains of anaerobic bacteria capable of reducing azo dyes were isolated from human feces and identified as eubacterium hadrum (2 strains), eubacterium spp. (2 species), clostridium clostridiiforme, a butyrivibrio sp., a bacteroides sp., clostridium paraputrificum, clostridium nexile, and a clostridium sp. the average rate of reduction of direct blue 15 dye (a dimethoxybenzid ...19902202258
nucleotide sequence of the ruminococcus albus sy3 endoglucanase genes cela and celb.the complete nucleotide sequences of ruminococcus albus genes cela and celb coding for endoglucanase a (ega) and endoglucanase b (egb), respectively, have been determined. the cela structural gene consists of an open reading frame of 1095 bp. confirmation of the nucleotide sequence was obtained by comparing the predicted amino acid sequence with that derived by n-terminal analysis of purified ega. the celb structural gene consists of an open reading frame of 1227 bp; 7 bp upstream of the transla ...19902250649
sequencing and expression of a cellodextrinase (ced1) gene from butyrivibrio fibrisolvens h17c cloned in escherichia coli.the nucleotide sequence of a 2.314 kb dna segment containing a gene (ced1) expressing cellodextrinase activity from butyrivibrio fibrisolvens h17c was determined. the b. fibrisolvens h17c gene was expressed from a weak internal promoter in escherichia coli and a putative consensus promoter sequence was identified upstream of a ribosome binding site and a gtg start codon. the complete amino acid sequence (547 residues) was deduced and homology was demonstrated with the clostridium thermocellum en ...19902250655
cloning, sequencing and analysis of expression of a butyrivibrio fibrisolvens gene encoding a beta-glucosidase.the cloning, expression and nucleotide sequence of a 3.74 kb dna segment on pls215 containing a beta-glucosidase gene (bgla) from butyrivibrio fibrisolvens h17c was investigated. the b. fibrisolvens bgla open reading frame (orf) of 2490 bp encoded a beta-glucosidase of 830 amino acid residues with a calculated mr of 91,800. in escherichia coli c600(pls215) cells the beta-glucosidase was localized in the cytoplasm and these cells produced an additional protein with an apparent mr of approximately ...19902262790
cloning and sequencing of the cela gene encoding endoglucanase a of butyrivibrio fibrisolvens strain a46.genomic dna from butyrivibrio fibrisolvens strain a46 was digested with ecori and ligated into lambda gt11. two recombinant phages isolated from the gene bank hydrolysed carboxymethylcellulose and were shown to contain the same 2.3 kb ecori restriction fragment, which was cloned into puc12 to generate pba46. escherichia coli jm83 harbouring pba46 expressed an endoglucanase (ega) which hydrolysed a range of other substrates including barley beta-glucan, avicel, filter paper and p-nitrophenyl beta ...19902269875
physiology and genetics of xylan degradation by gastrointestinal tract bacteria.hemicelluloses or xylans are major components (35%) of plant materials. for ruminant animals, about 50% of the dietary xylans are degraded, but only small amounts of xylans are degraded in the lower gut of nonruminant animals and humans. in the rumen, the major xylanolytic species are butyrivibrio fibrisolvens and bacteroides ruminicola. in the human colon, bacteroides ovatus and bacteroides fragilis subspecies "a" are major xylanolytic bacteria. xylans are chemically complex, and their degradat ...19902283426
4-o-(1-carboxyethyl)-l-rhamnose, a second unique acidic sugar found in an extracellular polysaccharide from butyrivibrio fibrisolvens strain 49.butyrivibrio fibrisolvens strain 49 excretes a polysaccharide that contains d-glucose, d-galactose, 4-o-(1-carboxyethyl)-d-galactose, and an acidic component of previously unknown structure. we report here the identity of the unknown as 4-o-(1-carboxyethyl)-l-rhamnose. the structure of this previously unknown compound was deduced from (1) comprehensive electron-impact and chemical-ionization mass-spectroscopic studies of differentially labelled derivatives prepared from the unknown, (2) 13c-n.m. ...19902363673
starch utilization by the human large intestinal microflora.high levels (2-565 units/g) of amylase activity were observed in human faeces. over 92% of amylase activity in faeces obtained from healthy persons was extracellular, whereas only about 9% of activity was associated with particulate material and washed cells. bacterial cell-bound amylases were considerably more efficient in breaking down starch, however, than were the soluble enzymes which occurred in cell-free faecal supernatant fluids. cell population densities of anaerobic starch-hydrolysing ...19862423494
amylolytic activity of selected species of ruminal bacteria.a variety of species of ruminal bacteria were screened for the ability to grow in starch-containing medium and produce amylase. of those tested, the highest levels of amylase were produced by streptococcus bovis jb1 and ruminobacter amylophilus h18. other strains that grew well on starch and produced amylase included butyrivibrio fibrisolvens a38 and 49 and bacteroides ruminicola 23 and b14. varying the carbohydrate source provided for growth resulted in changes in the growth rate and level of a ...19882454075
identification of the butyrivibrio fibrisolvens xylosidase gene (xylb) coding region and its expression in escherichia coli.the gene encoding the principal butyrivibrio fibrisolvens xylosidase (xylb) has been cloned and expressed in escherichia coli under the control of the lac promoter. the coding region for this gene was localized within a 3.2-kilobase b. fibrisolvens dna fragment in puc18. a new protein band was observed in recombinant e. coli containing xylb. this protein (approximately 60,000 molecular weight) was presumed to be the xylosidase monomer. the optimal ph (5.5) and substrate range for the recombinant ...19892497707
inducible bacteriophages from ruminal bacteria.the incidence of temperate bacteriophage in a wide range of ruminal bacteria was investigated by means of induction with mitomycin c. supernatant liquid from treated cultures was examined for phagelike particles by using transmission electron microscopy. of 38 ruminal bacteria studied, nine organisms (23.7%) representing five genera (eubacteria, bacteroides, butyrivibrio, ruminococcus, and streptococcus) produced phagelike particles. filamentous particles from butyrivibrio fibrisolvens are the f ...19892504111
cloning and sequencing of an endoglucanase (end1) gene from butyrivibrio fibrisolvens h17c.the nucleotide sequence of a 2.8 kb dna segment containing an endoglucanase gene (end1) from butyrivibrio fibrisolvens h17c was determined. the b. fibrisolvens h17c gene was expressed from its own regulatory region in escherichia coli and three putative consensus promoter sequences were identified upstream of a ribosome binding site and an atg start codon. the complete amino acid sequence (547 residues) was deduced and homology with the clostridium thermocellum cele gene product (ege) was demons ...19892615759
ruminal cellulolytic bacteria and protozoa from bison, cattle-bison hybrids, and cattle fed three alfalfa-corn diets.ruminal cellulolytic bacteria and protozoa and in vitro digestibility of alfalfa fiber fractions were compared among bison, bison hybrids, and crossbed cattle (five each) when they were fed alfalfa and corn in a ratio of 100:0, 75:25, and 50:50, respectively. the total number of viable bacteria (2.16 x 10(9) to 5.44 x 10(9)/ml of ruminal fluid) and the number of cellulolytic bacteria (3.74 x 10(7) to 10.9 x 10(7)/ml) were not different among groups of animals fed each diet. the genera of protozo ...19892705767
occurrence of 2-aminoethylphosphonic acid in feeds, ruminal bacteria and duodenal digesta from defaunated sheep.a quantitative method of analysis for 2-aminoethylphosphonic acid (aep) was developed using reverse-phase hplc. the detection limit for aep was 15 nm, and the detector response (peak area) was linear from aep levels up to 100 microm (r = .99). mean recovery of aep added to strained ruminal fluid from faunated sheep was 98.2%. when aep was added to a fermentation mixture at a concentration of 22.6 micrograms/ml, 78% disappeared during a 24-h incubation. 2-aminoethylphosphonic acid was readily det ...19892715111
the characterization and ultrastructure of two new strains of butyrivibrio.strains b-385-1 and 2-33 are numerically important components rumen bacterial populations , but they have remained (taxonomically) undefined. in spite of some resemblance to selenomonas ruminantium in their cell size and in their formation of tufts of flagella, they more closely resemble butyrivibrio fibrisolvens in the subpolar location of their flagella, in their guanine + cytosine content, and in most biochemical characteristics, including butyrate formation. cells of these strains stain gram ...19892743214
characterization of membrane lipids of a general fatty acid auxotrophic bacterium by electron spin resonance spectroscopy and differential scanning calorimetry.lipids in the plasma membrane of the general fatty acid auxotroph butyrivibrio s2 pack as a bilayer that is characterized by a high order and high motional anisotropy and a low membrane fluidity compared to mammalian plasma membranes. lipid packing as determined by the electron spin resonance (esr) order parameter and membrane fluidity as measured by esr correlation times are, however, comparable to those of other bacterial membranes. membranes of the organism grown with saturated fatty acids of ...19853000428
seasonal changes in the cecal microflora of the high-arctic svalbard reindeer (rangifer tarandus platyrhynchus).the dominant cecal bacteria in the high-arctic svalbard reindeer were characterized, their population densities were estimated, and cecal ph was determined in summer, when food quality and availability is good, and in winter, when it is very poor. in summer the total culturable viable bacterial population was (8.9 +/- 5.3) x 10(8) cells ml-1, whereas in winter it was (1.5 +/- 0.7) x 10(8) cells ml-1, representing a decrease to 17% of the summer population density. of the dominant species of cult ...19873030193
effects of several mycotoxins on specific growth rate of butyrivibrio fibrisolvens and toxin degradation in vitro.four strains of butyrivibrio fibrisolvens did not degrade aflatoxin b1. acetyl t-2 toxin, t-2 toxin, ht-2 toxin, deoxynivalenol, diacetoxyscirpenol, verrucarin a, zearalenone, and ochratoxin a did not affect the specific growth rate of b. fibrisolvens ce51 significantly, but all were degraded to greater or lesser extents. breakdown products were produced as a result of deacetylation reactions.19873107465
factors affecting the rate of breakdown of bacterial protein in rumen fluid.1. the cellular proteins of butyrivibrio fibrisolvens, lactobacillus casei, megasphaera elsdenii, selenomonas ruminantium and streptococcus bovis were labelled by growth in the presence of l-[14c]leucine, and the breakdown of labelled protein was measured in incubations of these bacteria with rumen fluid to which unlabelled 5 mm-l-leucine was added. the rate of protein breakdown was estimated from the rate of release of radioactivity into acid-soluble material. 2. protein breakdown occurred at d ...19873118940
fermentation of xylans by butyrivibrio fibrisolvens and other ruminal bacteria.the ability of butyrivibrio fibrisolvens and other ruminal bacteria (6 species, 18 strains) to ferment a crude xylan from wheat straw or to ferment xylans from larchwood or oat spelts was studied. liquid cultures were monitored for carbohydrate utilization, cell growth (protein), and fermentation acid production. b. fibrisolvens 49, h17c, actf2, and d1 grew almost as well on one or more of the xylans as they did on cellobiose-maltose. b. fibrisolvens 12, r28, a38, x10c34, ard22a, and x6c61 exhib ...19873124741
esterase activities in butyrivibrio fibrisolvens strains.thirty strains of butyrivibrio fibrisolvens isolated in diverse geographical locations were examined for esterase activity by using naphthyl esters of acetate, butyrate, caprylate, laurate, and palmitate. all strains possessed some esterase activity, and high levels of activity were observed with strains 49, h17c, s2, actf2, and lm8/1b. esterase activity also was detected in other ruminal bacteria (bacteroides ruminicola, selenomonas ruminantium, ruminobacter amylophilus, and streptococcus bovis ...19883178205
4-o-(1-carboxyethyl)-d-galactose. a new acidic sugar from the extracellular polysaccharide produced by butyrivibrio fibrisolvens strain 49.the structure of a new acidic sugar from the extracellular polysaccharide of butyrivibrio fibrisolvens strain 49 was determined as 4-o-(1-carboxyethyl)-d-galactose on the basis of 13c-n.m.r. and 1h-n.m.r. spectroscopy, m.s. and chemical degradation studies.19883223950
uncommonly encountered, motile, anaerobic gram-negative bacilli associated with infection.motile, anaerobic gram-negative bacilli belonging to the genera butyrivibrio, succinimonas, succinivibrio, anaerovibrio, wolinella, campylobacter, desulfovibrio, selenomonas, and anaerobiospirillum are being recognized in clinical specimens with increasing frequency. over a 12.5-year period at the va wadsworth medical center, 13 clinical specimens yielded one of these organisms. six isolates were recovered from infected wounds, five from respiratory tract specimens obtained from patients with an ...19873321364
neutral sugar composition of extracellular polysaccharides produced by strains of butyrivibrio fibrisolvens.the extracellular polysaccharides (epss) produced by 37 isolates presently classified as butyrivibrio species (or more specifically as butyrivibrio fibrisolvens) were purified from glucose-grown cultures. the neutral sugar compositions of these epss were determined by both thin-layer and gas-liquid chromatographic techniques. results showed that while the neutral sugar composition of the eps was constant for a given strain, it varied considerably between strains. in addition, several acidic comp ...19883377501
synergism of rumen microbial hydrolases during degradation of plant isolated mixture of exocellular enzymes of rumen bacteria ruminococcus flavefaciens, butyrivibrio fibrisolvens and rumen fungus neocallimastix frontalis, specific activities of cellulases, hemicellulases and glycosidases were determined. the highest specific activities were shown mostly for proteins of n. frontalis.19883397009
enumeration and isolation of cellulolytic and hemicellulolytic bacteria from human feces.the fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (ahp-ws), whereas degradation of the relatively crystalline cellulose in whatman no. 1 filter paper (pmc) was detected for only one of the five samples. the mean ...19883415224
effects of potassium ion concentrations on the antimicrobial activities of ionophores against ruminal anaerobes.the antimicrobial activities of monensin and lasalocid against representative strains of ruminal bacteria were evaluated in medium containing three different concentrations of potassium (1.3, 7.9, or 23.3 mm). the growth of eubacterium ruminantium was inhibited by low concentrations of ionophores (less than or equal to 0.16 mg/liter), while the strain of streptococcus bovis tested was resistant to high concentrations of ionophores (40 mg/liter) at all potassium concentrations tested. the mics of ...19873426214
interactions between rumen amylolytic and lactate-utilizing bacteria in growth on starch.the growth and metabolism of the rumen amylolytic bacteria streptococcus bovis, butyrivibrio fibrisolvens and bacteroides ruminicola, growing in pure cultures and co-cultures with the rumen lactilytic bacteria megasphaera elsdenii and veillonella alcalescens were followed. the interaction of amylolytic bacteria with v. alcalescens represents a simple food chain. the interaction with m. elsdenii is more complex, since there is a simultaneous competition for products of the starch degradation.19873429358
proteolytic activity of the ruminal bacterium butyrivibrio fibrisolvens.the proteolytic activity of butyrivibrio fibrisolvens, a ubiquitously distributed bacterial species in the gastrointestinal tracts of ruminants and other mammals, was characterized. the relative proteolytic activity (micrograms of azocasein degraded per hour per milligram of protein) varied greatly with the strain: 0 to 1 for strains d1, d16f, e21c, and x6c61; 7 to 15 for strains il631, nor37, s2, lm8/1b, and x10c34; and 90 to 590 for strains 12, 49 h17c, cf4c, cf3, cf1b, and r28. the activity l ...19863524460
t-2 toxin metabolism by ruminal bacteria and its effect on their growth.the effect of t-2 toxin on the growth rates of different bacteria was used as a measure of its toxicity. toxin levels of 10 micrograms/ml did not decrease the growth rate of selenomonas ruminantium and anaerovibrio lipolytica, whereas the growth rate of butyrivibrio fibrisolvens was uninhibited at toxin levels as high as 1 mg/ml. there was, however, a noticeable increase in the growth rate of b. fibrisolvens ce46 and ce51 and s. ruminantium in the presence of low concentrations (10 micrograms/ml ...19873579272
protein degradation by ruminal microorganisms from sheep fed dietary supplements of urea, casein, or albumin.ruminal fluid from sheep fed hay plus concentrate diets containing 1.8% urea, 6% casein, or 6% egg albumin had proteolytic activities of 4.12, 3.02, or 4.00 mg of [14c]casein hydrolyzed ml-1 h-1, respectively. dietary albumin had no effect on the rate of albumin breakdown relative to that of casein (0.06). greater numbers of highly proteolytic bacteria, mainly butyrivibrio spp., were isolated from the rumens of sheep receiving albumin. albumin hydrolysis by these isolates was even slower relativ ...19873579280
stoichiometry of glucose and starch splitting by strains of amylolytic bacteria from the rumen and anaerobic digester.the stoichiometry of glucose and starch splitting by the amylolytic bacteria streptococcus bovis, selenomonas ruminantium, butyrivibrio fibrisolvens, eubacterium ruminantium and clostridium sp. was followed. there were many differences in the ratios of metabolites and in growth yields, as well as in the cell composition, between the growth on glucose and starch. the bacteria employ different nutritional strategies with respect to both energy sources.19863759723
effect of phenolic monomers on ruminal bacteria.ruminal bacteria were subjected to a series of phenolic compounds in various concentrations to acquire fundamental information on the influence on growth and the potential limits to forage utilization by phenolic monomers. ruminococcus albus 7, ruminococcus flavefaciens fd-1, butyrivibrio fibrisolvens 49, and lachnospira multiparus d-32 were tested against 1, 5, and 10 mm concentrations of sinapic acid, syringaldehyde, syringic acid, ferulic acid, vanillin, vanillic acid, p-coumaric acid, p-hydr ...19863789721
phosphoenolpyruvate-dependent phosphorylation of hexoses by ruminal bacteria: evidence for the phosphotransferase transport system.six species of ruminal bacteria were surveyed for the phosphoenolpyruvate (pep)-dependent phosphorylation of glucose. selenomonas ruminantium hd4, streptococcus bovis jb1, and megasphaera elsdenii b159 all showed significant activity, but butyrivibrio fibrisolvens 49, bacteroides succinogenes s85, and bacteroides ruminicola b1(4) showed low rates of pep-dependent phosphorylation and much higher rates in the presence of atp. s. ruminantium hd4, s. bovis jb1, and m. elsdenii b159 also used pep to ...19863789722
seasonal changes in the ruminal microflora of the high-arctic svalbard reindeer (rangifer tarandus platyrhynchus).the dominant rumen bacteria in high-arctic svalbard reindeer were characterized, their population densities were estimated, and ruminal ph was determined in summer, when food quality and availability are good, and in winter, when they are poor. in summer the total cultured viable population density was (2.09 +/- 1.26) x 10(10) cells ml-1, whereas in winter it was (0.36 +/- 0.29) x 10(10) cells ml-1, representing a decrease to 17% of the summer population density. on culture, butyrivibrio fibriso ...19854026289
the rumen microbiology of seaweed digestion in orkney sheep.the microbial populations of the rumens of seaweed-fed and pasture-fed orkney sheep were examined. the populations in the pasture-fed sheep were similar to those of other domestic ruminants fed on land plants, but those of the seaweed-fed animals showed major differences in the dominant species. total ciliate populations were quantitatively similar, but in the seaweed-fed animals dasytricha ruminantium was one of the most dominant species. no phycomycete fungi or cellulolytic bacteria were found ...19854030526
microbiology and ration digestibility in the hindgut of the ovine.contents of the terminal ilea, ceca-proximal colons, and terminal recta were obtained from nine sheep, three of which were fed 100% orchardgrass hay, three of which were fed 60% cracked corn-40% orchardgrass hay, and three of which were fed 80% cracked corn-20% orchardgrass hay. the digestibility of dry matter in the ceca was greatest when the all-hay diet was fed, whereas the percentage of cellulose digestion in the ceca increased with increasing levels of concentrate. for all diets, the total ...19854051484
an exo-d-galacturonanase of butyrivibrio fibrisolvens from the bovine intracellular pectinolytic enzyme was isolated from a cell extract of butyrivibrio fibrisolvens and purified. the optimum ph for enzyme activity was 5.6. the enzyme preferentially degraded de-esterified substrates by hydrolysis of monosaccharide units from the non-reducing end; the only product of degradation was d-galacturonic acid. values of km and vmax for oligo- and polygalacturonates indicated that the best substrate was digalacturonic acid; oligogalacturonates containing either a satura ...19854056742
common antigenic determinant in a rumen organism and in salmonellae containing the antigen o4.nineteen of 28 strains of rumen organisms isolated from a cow on a high roughage diet and identified morphologically as butyrivibrios, reacted to a low agglutinin titer with salmonella antisera, forming five groups. however only one strain reacted with polyvalent o salmonella antiserum. this strain reacted with o4 factor serum and with antisera to salmonella strains containing the antigen o4, and agglutinin absorption tests showed the presence of an antigen identical to o4. when 16 further strai ...19724117663
variations in enzyme activities of butyrivibrio fibrisolvens and ruminococcus albus grown in continuous culture. 19744275991
the biohydrogenation of alpha-linolenic acid and oleic acid by rumen micro-organisms.1. alpha-[u-(14)c]linolenic acid was incubated with the rumen contents of sheep and the metabolic products were characterized by thin-layer chromatography, gas-liquid chromatography and absorption spectroscopy in the ultraviolet and infrared. 2. a tentative scheme for the biohydrogenation route to stearic acid is presented. the main pathway is through diconjugated cis-cis-cis-octadecatrienoic acid, non-conjugated trans-cis (cis-trans)-octadecadienoic acid and trans-octadecenoic acid, but other p ...19664287407
characterization of the lipids of butyrivibrio fibrisolvens.butyrivibrio fibrisolvens strain d-1 was grown on a lipid-free chemically defined medium. the lipids were extracted with chloroform-methanol and separated into nonpolar and polar fractions by silicic acid column chromatography. further separations were made by preparative thin-layer chromatography. the lipid fractions were identified by specific staining reactions and r(f) values, by phosphorus and nitrogen determinations, by chromatography of hydrolysis products, and by the use of infrared spec ...19704316361
enzymatic studies of pure cultures of rumen microorganisms.joyner, a. e., jr. (university of california, davis), and r. l. baldwin. enzymatic studies of pure cultures of rumen microorganisms. j. bacteriol. 92:1321-1330. 1966.-the activities of enzymes representing the major pathways of carbohydrate metabolism and anaerobic electron transport in cell-free extracts of whole rumen contents have been reported. the effects of diet upon the activities of several enzymes suggested that enzymatic measurements might prove useful for the study of rumen metabolism ...19664380801
fermentation of isolated pectin and pectin from intact forages by pure cultures of rumen bacteria.studies on the rate and extent of galacturonic acid and isolated pectin digestion were carried out with nine strains of rumen bacteria (butyrivibrio fibrisolvens h10b and d16f, bacteroides ruminicola 23 and d31d, lachnospira multiparus d15d, peptostreptococcus sp. d43e, b. succinogenes a3c, ruminococcus flavefaciens b34b, and r. albus 7). only three strains, 23, d16f, and d31d, utilized galacturonic acid as a sole energy source, whereas all strains except a3c and h10b degraded (solubilized) and ...19724552890
characterization of esterases produced by a ruminal bacterium identified as butyrivibrio obligately anaerobic ruminal bacterial isolate was selected from 18 tributyrin-degrading isolates and identified as butyrivibrio fibrisolvens strain 53. the culture in late exponential phase contained enzymes which could be released by sonic disruption. these enzymes degraded substrates at a rate in the order 1-naphthyl acetate (na) > 1-naphthyl butyrate > 1-naphthyl propionate but did not degrade 1-naphthyl palmitate or 1-naphthyl phosphate. the enzymes on na were neither stimulated nor inhi ...19734734862
enzymes of intermediary metabolism of butyrivibrio fibrisolvens and ruminococcus albus grown under glucose limitation. 19734796347
biohydrogenation of unsaturated fatty acids. iv. substrate specificity and inhibition of linoleate delta-12-cis, delta-11-trans-isomerase from butyrivibrio fibrisolvens. 19704990474
identification of products produced by the anaerobic degradation of naringin by butyrivibrio sp. c3. 19715103057
oxygen sensitivity of various anaerobic bacteria.anaerobes differ in their sensitivity to oxygen, as two patterns were recognizable in the organisms included in this study. strict anaerobes were species incapable of agar surface growth at po(2) levels greater than 0.5%. species that were found to be strict anaerobes were treponema macrodentium, treponema denticola, treponema oralis n. sp., clostridium haemolyticum, selenomonas ruminatium, butyrivibrio fibrisolvens, succinivibrio dextrinosolvens, and lachnospira multiparus. moderate anaerobes w ...19695370458
characteristics of ruminococcus and cellulolytic butyrivibrio species from the rumens of sheep fed differently supplemented teff (eragrostis tef) hay diets. 19705516604
identification of products produced by the anaerobic degradation of rutin and related flavonoids by butyrivibrio sp. c3. 19705530120
carbon dioxide requirement of various species of rumen bacteria.the carbon dioxide requirement of 32 strains of rumen bacteria, representing 11 different species, was studied in detail. increasing concentrations of co(2) were added as nahco(3) to a specially prepared co(2)-free medium which was tubed and inoculated under nitrogen. prior depletion of co(2) in the inoculum was found to affect the level of requirement; however, the complexity and buffering capacity of the medium did not appear to be involved. an absolute requirement for co(2) was observed for e ...19715541030
biohydrogenation of unsaturated fatty acids. v. stereospecificity of proton addition and mechanism of action of linoleic acid delta 12-cis, delta 11-trans-isomerase from butyrivibrio fibrisolvens. 19715554292
biohydrogenation of unsaturated fatty acids. 3. purification and properties of a linoleate delta-12-cis, delta-11-trans-isomerase from butyrivibrio fibrisolvens. 19675633396
lysis of viable rumen bacteria in bovine rumen fluid.streptococcus bovis and butyrivibrio sp. were labeled with thymidine-methyl-(3)h, washed, and resuspended in rumen fluid or rumen fluid fractions obtained from holstein and jersey cows fed alfalfa hay once daily. factors affecting the lytic activity found in untreated rumen fluid were examined. day to day variation and differences before and after feeding were observed for the same cow. there were also differences between cows on the same day. for a given rumen fluid, the rate of release of labe ...19685659364
characterization of several bovine rumen bacteria isolated with a xylan medium.dehority, b. a. (ohio agricultural research and development center, wooster). characterization of several bovine rumen bacteria isolated with a xylan medium. j. bacteriol. 91:1724-1729. 1966.-studies were conducted to characterize eight strains of bacteria isolated from bovine rumen contents, by use of a medium containing xylan as the only added carbohydrate source. based on morphology, biochemical reactions, nutritional requirements, and fermentation products, five of the eight strains were ide ...19665937235
the hydrogenation of gamma-linolenic acid by pure cultures of two rumen bacteria.two species of rumen bacteria that have been previously shown to partially hydrogenate alpha-linolenic acid have been examined for their ability to hydrogenate gamma-linolenic acid. free gamma-linolenic acid is hydrogenated in vitro to stearic acid by a rumen fusocillus sp. (n.c.i.b. 11026), but only to cis,trans-octadec-6,11-enoic acid by a butyrivibrio sp. the sequential hydrogenations are preceded by a delta 12-cis-delta 11-trans isomerization identical with that observed in the hydrogenation ...19836318740
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