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intracellular ph of acid-tolerant ruminal bacteria.acid-tolerant ruminal bacteria (bacteroides ruminicola b1(4), selenomonas ruminantium hd4, streptococcus bovis jb1, megasphaera elsdenii b159, and strain f) allowed their intracellular ph to decline as a function of extracellular ph and did not generate a large ph gradient across the cell membrane until the extracellular ph was low (less than 5.2). this decline in intracellular ph prevented an accumulation of volatile fatty acid anions inside the cells.19911781695
succinate transport by a ruminal selenomonad and its regulation by carbohydrate availability and osmotic strength.washed cells of strain h18, a newly isolated ruminal selenomonad, decarboxylated succinate 25-fold faster than selenomonas ruminantium hd4 (130 versus 5 nmol min-1 mg of protein-1, respectively). batch cultures of strain h18 which were fermenting glucose did not utilize succinate, and glucose-limited continuous cultures were only able to decarboxylate significant amounts of succinate at slow (less than 0.1 h-1) dilution rates. strain h18 grew more slowly on lactate than glucose (0.2 versus 0.4 h ...19912036012
mechanism of action of d-galacturonan digalacturonohydrolase of selenomonas ruminantium on oligogalactosiduronic acids.the mechanism of action of the specific d-galacturonan digalacturonohydrolase [poly-(1----4)-alpha-d-galactosiduronate digalacturonohydrolase, ec 3.2.1.82] of selenomonas ruminantium was investigated by using reducing-end [1-3h]-labeled oligogalactosiduronates having degree of polymerization 3-5 as the substrates. the reaction products, incorporation and distribution of radioactivity in products, and the frequency of oligogalactosiduronate bond-cleavage were quantitatively estimated as functions ...19921473108
effect of direct-fed microbials on rumen microbial fermentation.nonbacterial, direct-fed microbials added to ruminant diets generally consist of aspergillus oryzae fermentation extract, or saccharomyces cerevisiae cultures, or both. results from in vivo research have been variable regarding effects of direct-fed microbials on ruminant feedstuff utilization and performance. some research has shown increased weight gains, milk production, and total tract digestibility of feed components, but others have shown little influence of direct-fed microbials on these ...19921500571
enzymes associated with metabolism of xylose and other pentoses by prevotella (bacteroides) ruminicola strains, selenomonas ruminantium d, and fibrobacter succinogenes s85.prevotella (bacteroides) ruminicola strains b(1)4 and s23 and selenomonas ruminantium strain d used xylose as the sole source of carbohydrate for growth, whereas fibrobacter succinogenes was unable to metabolize xylose. prevotella ruminicola strain b(1)4 exhibited transport activity for xylose. in contrast, f. succinogenes lacked typical xylose uptake activity but did exhibit low binding potential for the sugar. prevotella ruminicola strains b(1)4 and s23 as well as s. ruminantium d showed low x ...19921643581
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
complete nucleotide sequence of a selenomonas ruminantium plasmid and definition of a region necessary for its replication in escherichia coli.a plasmid from selenomonas ruminantium subspecies lactilytica has been subcloned in escherichia coli k-12 and completely sequenced. three open reading frames (orfs) of 909, 801, and 549 bp were identified and the complete sequence was analyzed by comparison with dna and protein databases. no significant deoxynucleotide or amino acid sequence homology with other published genes or proteins was detected. the plasmid was shown to replicate independently in e. coli k-12 by a dna polymerase i-depende ...19921409969
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
p-coumaroyl and feruloyl arabinoxylans from plant cell walls as substrates for ruminal bacteria.growth of the ruminal bacteria ruminococcus flavefaciens fd1, selenomonas ruminantium hd4, and butyrivibrio fibrisolvens 49 was limited by ester-linked feruloyl and p-coumaroyl groups. the limitation of growth on phenolic acid-carbohydrate complexes varied with individual bacteria and appeared to be influenced by ability to hydrolyze carbohydrate linkages.19938434931
srui restriction endonuclease from selenomonas ruminantium.srui, specific restriction endonuclease, has been characterized from selenomonas ruminantium isolated from the rumen of fallow deer. results from the study demonstrate that s. ruminantium 18d possesses a type ii restriction endonuclease, which recognizes the sequence 5'-ttt decreases aaa-3'. the recognition sequence of srui was identified using digestions on pbr322, pbr328, puc18, m13mp18rf, pacyc184 and lambda dna. the cleavage patterns obtained were compared with computer-derived data. srui re ...19938262361
utilization of xylooligosaccharides by selected ruminal bacteria.the ability of ruminal bacteria to utilize xylooligosaccharides was examined. xylooligosaccharides were prepared by partially hydrolyzing oat spelt xylan in phosphoric acid. this substrate solution was added (0.2%, wt/vol) to a complex medium containing yeast extract and trypticase that was inoculated with individual species of ruminal bacteria, and growth and utilization were monitored over time. all of the xylanolytic bacteria examined were able to utilize this oligosaccharide mixture as a gro ...19938285663
proposal of quinella ovalis gen. nov., sp. nov., based on phylogenetic analysis.quin's oval is a relatively large bacterium often seen in the rumens of sheep fed diets containing some readily fermented carbohydrates. it has not been obtained in axenic cultures, but a number of its features have been determined by various methods, such as studying cell suspensions purified from rumen fluid by differential centrifugation. we obtained similarly purified suspensions from a sheep fed a diet containing a large amount of molasses. nearly complete 16s rrna sequence analysis of thes ...19937684240
isolation and characterization of selenomonas ruminantium strains capable of 2-deoxyribose utilization.microbes from ruminal contents of cattle were selectively enriched by using 2-deoxyribose (2dr) as a substrate for growth. bacterial isolates growing on 2dr were gram-negative, curved, motile rods. the isolates grew on a broad range of substrates, including deoxyribose, glucose, ribose, mannitol, and lactate as well as ribonucleosides and deoxyribonucleosides. the strains also grew on rhamnose (6-deoxymannose) but not dna. organic acids produced from growth on hexoses and pentoses included aceta ...19938357244
binding and degradation of lectins by components of rumen liquor.the binding of 15 different plant lectins to feed particles and microbes in rumen liquor, and their degradation were studied in vitro. the rate of degradation assessed from the label released when radioactive iodine-labelled lectins were incubated with rumen liquor conflicted with the rates calculated from measurements of the survival of the antigenic structure (immuno-rocket electrophoresis) or the biological function (haemagglutination) of the lectins. thus solubilization of the radioactive la ...19938420916
evidence for catabolite inhibition in regulation of pentose utilization and transport in the ruminal bacterium selenomonas ruminantium.pentose sugars can be an important energy source for ruminal bacteria, but there has been relatively little study regarding the regulation of pentose utilization and transport by these organisms. selenomonas ruminantium, a prevalent ruminal bacterium, actively metabolizes xylose and arabinose. when strain d was incubated with a combination of glucose and xylose or arabinose, the hexose was preferentially utilized over pentoses, and similar preferences were observed for sucrose and maltose. howev ...19938439166
isolation and attempted introduction of sugar alcohol-utilizing bacteria in the sheep rumen.bacteria that use sorbitol, xylitol, maltitol and dulcitol (galactitol) were isolated from the sheep rumen following enrichments in which bacteria were grown in rumen fluid medium where the sugar alcohol was the only added energy source. only isolates obtained with sorbitol and maltitol grew sufficiently rapidly to be considered for enrichment by the sugar alcohol in vivo. isolate ss2, a strain of selenomonas ruminantium var. lactilytica which grew on sorbitol at 0.87 h-1, was selected for furth ...19938486540
characterization, sequence, and replication of a small cryptic plasmid from selenomonas ruminantium subspecies lactilytica.a 2.5-kb cryptic plasmid, pjdb21, from the gram-negative ruminal anaerobe, selenomonas ruminantium subspecies lactilytica, was mapped and sequenced. five open reading frames (orfs) were predicted and expression of two orfs was demonstrated. analysis of the predicted amino acid sequence of the orf 1 protein indicated approximately 30% homology with the replication protein (rep) common to many gram-positive plasmids, and a highly conserved sequence representing the origin of replication in these p ...19938469719
restriction endonucleases from selenomonas ruminantium which recognize and cleave 5'-at/taat-3'.two natural isolates from fallow-deer rumen identified as selenomonas ruminantium were found to produce a restriction endonuclease which we called sru4di. this enzyme was isolated from cell extracts by phosphocellulose chromatography. analysis of the sru4di recognition site showed that sru4di recognizes the hexanucleotide sequence 5'-at/taat-3' generating 5'dinucleotide protruding ends upon cleavage and thus is a true isoschizomer of vspi, a restriction enzyme isolated from vibrio sp.19948042908
nutrient transport by ruminal bacteria: a review.fermentation pathways have been elucidated for predominant ruminal bacteria, but information is limited concerning the specific transport mechanisms used by these microorganisms for c, energy, and n sources. in addition, it is possible that changes in ruminal environmental conditions could affect transport activity. five carrier-mediated soluble nutrient transport mechanisms have been identified in bacteria: 1) facilitated diffusion, 2) shock sensitive systems, 3) proton symport, 4) na+ symport, ...19947730197
factors affecting l-lactate utilization by selenomonas ruminantium.studies were conducted to evaluate factors that affect l-lactate utilization by the ruminal bacterium selenomonas ruminantium hd4. l-lactate uptake decreased over time both in the presence and absence of 10 mm l-malate. compared with uptake in the absence of malate, 10 mm l-malate increased l-lactate uptake at 30 s and 45 min. because l-malate had little effect on l-lactate uptake for cells grown on soluble carbohydrates compared to lactate-grown cells, it seems that the stimulation due to l-mal ...19948056684
ability of acidaminococcus fermentans to oxidize trans-aconitate and decrease the accumulation of tricarballylate, a toxic end product of ruminal fermentation.mixed ruminal bacteria convert trans-aconitate to tricarballylate, a tricarboxylic acid which chelates blood divalent cations and decreases their availability (j. b. russell and p. j. van soest, appl. environ. microbiol. 47:155-159, 1984). decreases in blood magnesium in turn cause a potentially fatal disease known as grass tetany. trans-aconitate was stoichiometrically reduced to tricarballylate by selenomonas ruminantium, a common ruminal bacterium in grass-fed ruminants (j. b. russell, appl. ...19948074529
[rumen bacterial metabolism as affected by extracellular redox potential].the redox potential (eh) in the digestive tract of ruminants varies mostly within the ranges from -300 to +200 mv, in the rumen medium: from -130 to -200 mv. eh and ph changes are of a linear character. enhanced fermentation moves eh towards negative values and improves growth of microorganisms. eh values become even more negative as affected by na2s, naoh, cysteine and nahso3. addition of picrate, sodium nitrate, hydrochloric acid, copper sulphate, gaseous oxygen and particularly heavy metals ( ...19947974836
alternative strategies of 2-deoxyglucose resistance and low affinity glucose transport in the ruminal bacteria, streptococcus bovis and selenomonas ruminantium.streptococcus bovis and selenomonas ruminantium grew in the presence of the glucose analog, 2-deoxyglucose (2-dg), but the cells no longer had high affinity glucose transport. in s. bovis, 2-dg resistance was correlated with a decrease in phosphoenolpyruvate (pep)-dependent glucose phosphotransferase (pts) activity. the 2-dg-selected s. bovis cells relied solely upon a low affinity, facilitated diffusion mechanism of glucose transport and a 2-dg-resistant glucokinase (atp-dependent). the glucoki ...19947988891
influence of yucca shidigera extract on ruminal ammonia concentrations and ruminal microorganisms.an extract of the desert plant yucca shidigera was assessed for its possible benefit in ruminal fermentation. the extract bound ammonia in aqueous solution when concentrations of ammonia were low (up to 0.4 mm) and when the extract was added at a high concentration to the sample (20%, vol/vol). the apparent ammonia-binding capability was retained after autoclaving and was decreased slightly following dialysis. acid-precipitated extract was inactive. no evidence of substantial ammonia binding was ...19948031077
cyclic amp in ruminal and other anaerobic bacteria.an examination of camp levels in predominant species of ruminal bacteria and other anaerobic bacteria was conducted. cellular camp concentrations of glucose-grown cultures of butyrivibrio fibrisolvens 49, prevotella ruminicola d31d, selenomonas ruminantium hd4 and d, megasphaera elsdenii b159, streptococcus bovis jb1, bacteroides thetaiotaomicron 5482, and clostridium acetobutylicum atcc 824 were determined at various times during growth by a competitive binding radioimmunoassay procedure. the r ...19947851742
multiple lactate dehydrogenase activities of the rumen bacterium selenomonas ruminantium.the lactate utilizing strain of selenomonas ruminantium 5934e was found to contain three lactate dehydrogenase (ldh) activities in sonicated cell extracts. one activity, an nad dependent l-ldh (l-nldh) was measured at 15-fold greater levels in extracts of cells grown to mid-exponential phase on glucose compared to cells grown to the equivalent growth stage on dl-lactate. a second nldh activity specific for d-lactate (d-nldh) was detected at similar levels in both lactate-grown cell extracts and ...19947921257
effect of extracellular lactate on growth of rumen lactate producers.the addition of na-lactate (50-150 mmol/l) to media with glucose had only marginal effect on the growth of rumen lactate-producing bacteria at ph between 6.5 and 5.8. butyrivibrio fibrisolvens was somewhat more sensitive to external lactate than streptococcus bovis, lactobacillus fermentum and selenomonas ruminantium. it can be concluded that rumen lactate producers, which proliferate at the onset of rumen lactic acidosis, are not influenced by the lactate accumulation, except some non-specific ...19947619002
the chronic patient: perspectives from the 29th institute on hospital & community psychiatry. making rehospitalization part of the plan [proceedings]. 1994201559
protein-binding assay for cyclic amp: possible interference by traces of trichloroacetate. 1995167609
the in vitro uptake and metabolism of peptides and amino acids by five species of rumen bacteria.streptococcus bovis jb1, prevotella ruminicola b(1)4, selenomonas ruminantium z108, fibrobacter succinogenes s85 and anaerovibrio lipolytica 5s were incubated with either 14c-peptides (mol. wt, 200-1000) or 14c-amino acids to compare their rates of uptake and metabolism. in experiment 1, the bacteria were grown and incubated in a complex medium, but no uptake of 14c-labelled substrates occurred. when casein digest was omitted, uptake rates of 14c-peptides were different (p < 0.01) with each spec ...19957698948
the cellular location of prevotella ruminicola beta-1,4-d-endoglucanase and its occurrence in other strains of ruminal bacteria.prevotella ruminicola b(1)4, tc1-1, tf1-3, and ts1-5 all produced immunologically cross-reacting 88- and 82-kda carboxymethyl cellulases (cmcases). p. ruminicola 23, 118b, 20-63, and 20-78 had much lower cmcase activities, and western blots (immunoblots) showed no cross-reaction with the b(1)4 cmcase antiserum. fibrobacter succinogenes s85 and selenomonas ruminantium hd4 and d produced cmcase, but these enzymes were smaller and did not cross-react with the b(1)4 cmcase antiserum. the b(1)4 cmcas ...19957574639
conversion of oleic acid to 10-hydroxystearic acid by two species of ruminal bacteria.bacteria able to convert oleic acid to 10-hydroxystearic acid were isolated from the ovine rumen. the solid hydroxy fatty acid produced from bacterial fermentations containing oleic acid was recovered by filtration, extraction into ether and crystallisation. the identity of the product was confirmed by hplc and gas chromatography/mass spectrometry. one 10-hydroxystearic-acid-producing bacterial group was represented by two strains of an anaerobic gram-negative curved rod with tufts of flagella o ...19958579822
rumen fermentation and metabolic profile in conventional and gnotobiotic lambs.observations were carried out of actual acidity, volatile fatty acid (vfa) concentrations, enzyme activity in the rumen, total protein, urea, total lipid and glucose in the serum of conventional (cl) and gnotobiotic lambs (gl) in the period of milk nutrition. the inoculum of gnotobiotic lambs contained streptococcus bovis, prevoxella ruminicola, butyrivibrio fibrisolvens and selenomonas ruminantium at a concentration of 1.10(6) each. throughout the observation period the ph of the rumen contents ...19958585797
isolation and characterization of a new restriction endonuclease, sru30di, from selenomonas ruminantium.the restriction endonuclease (enase) sru30di, an isoschizomer of stui, which recognizes the sequence 5'-agg/cct-3', was purified from a natural isolate of selenomonas ruminatinum. the enase was isolated from cell extracts using single-step purification by phosphocellulose column chromatography. activity of sru30di is inhibited by overlapping dcm methylation. the enase is extremely stable at 37 degrees c and is active over a wide range of ph, temperature and salt concentrations.19957789798
antimicrobial activity of lasalocid against selenomonas ruminantium--effect of changes in ph induced by changing glucose concentration.a significant decrease in ph occurred in the culture medium when cells of selenomonas ruminantium hd-4 were incubated in the presence of relatively high concentrations of glucose (0.4 and 1.0%). forty microm lasalocid reduced cell growth to 35.5 and 35.7% of control growth, respectively, for 0.05 and 0.4% glucose, while growth was completely inhibited by 40 microm lasalocid in the presence of 1.0% glucose. in the presence of 80 microm lasalocid, cells were unable to grow within 24 hr at any gluc ...19958519886
degradation and utilization of xylan by the ruminal bacteria butyrivibrio fibrisolvens and selenomonas ruminantium.the cross-feeding of xyland hydrolysis products between the xylanolytic bacterium butyrivibrio fibrisolvens h17c and the xylooligosaccharide-fermenting bacterium selenomonas ruminantium ga192 was investigated. cultures were grown anaerobically in complex medium containing oat spelt xylan, and the digestion of xylan and the generation and subsequent utilization of xylooligosaccharide intermediates were monitored over time. monocultures of b. fibrisolvens rapidly degraded oat spelt xylan, and a po ...19958534103
survey of urease activity in ruminal bacteria isolated from domestic and wild ruminants.a total of 909 strains, including selenomonas ruminantium, lactobacillus sp., enterococcus sp. and staphylococcus sp., from the rumen of 104 domestic and wild ruminants was used in tests for urease activity. tests showed that 56.7% of s. ruminantium strains and 18.5% of lactobacilli manifested medium urease activity with mean values of 14.4 +/- 2.5 and 13.85 +/- 0.25 nkat ml-1, respectively. most of the enterococcus faecium (62.2%) and all of the e. faecalis isolates expressed urease activity wi ...19958569526
characterization of tannin acylhydrolase activity in the ruminal bacterium selenomonas ruminantium.a strain of the anaerobe selenomonas ruminantium subsp. ruminantium that is capable of growing on tannic acid or condensed tannin as a sole energy source has been isolated from ruminal contents of feral goats browsing tannin-rich acacia sp. growth on tannic acid was accompanied by release of gallic acid into the culture medium but the bacterium was incapable of using gallic acid as a sole energy source. tannin acylhydrolase (ec 3.1.1.20) activity was measured in crude cell-free extracts of the b ...199516887543
use of fura-2/am to measure intracellular free calcium in selenomonas ruminantium.this paper describes a procedure for loading the acetoxymethyl ester of fura-2 (fura-2/am), and the subsequent measurement of the concentration of intracellular free ca2+ ([ca2+]i) in selenomonas ruminantium (s. ruminantium) using this technique. to ascertain the optimal loading conditions, the effect was examined on the loading of fura-2/am of ethylenediamine-tetraacetic acid (edta), lysozyme, pluronic f127 alone, or the simultaneous application of edta and pluronic f127. individual administrat ...19968944431
growth and fermentation responses of selenomonas ruminantium to limiting and non-limiting concentrations of ammonium chloride.the objective of this study was to assess fermentation product, growth rate and growth yield responses of selenomonas ruminantium hd4 to limiting and non-limiting ammonia concentrations. the ammonia half-inhibition constant for s. ruminantium in batch culture was 296 mm. cells were grown in continuous culture with a defined ascorbate-reduced basal medium containing either 0.5, 5, 25, 50, 100 or 200 mm nh4cl and dilution rates were 0.07, 0.14, 0.24 or 0.40 h-1. ammonia was the growth-limiting nut ...19968987647
ecology, metabolism, and genetics of ruminal selenomonads.selenomonas ruminantium is one of the more prominent and functionally diverse bacteria present in the rumen and can survive under a wide range of nutritional fluctuations. selenomonas is not a degrader of complex polysaccharides associated with dietary plant cell wall components, but is important in the utilization of soluble carbohydrates released from initial hydrolysis of these polymers by other ruminal bacteria. selenomonads have multiple carbon flow routes for carbohydrate catabolism and at ...19968729959
effect of extracellular hydrogen on organic acid utilization by the ruminal bacterium selenomonas ruminantium.the objective of this study was to evaluate the effect of extracellular h2 on organic acid utilization by two lactate-utilizing strains of selenomonas ruminantium (hd4, h18). both strains were able to grow (optical density at 600 nm > or = after 9 h) on either aspartate, fumarate, or malate in the presence of 1 atmosphere (atm) of h2. succinate was the major end product produced in these fermentations. when cells were incubated with lactate plus 1 atm h2, growth was minimal little lactate was fe ...19968640106
genetic transfer of lactate-utilizing ability in the rumen bacterium selenomonas ruminantium.matings between the lactate-utilizing, tetracycline-sensitive selenomonas ruminantium strains 5521c1 and 5934e and the lactate-non-utilizing, tetracycline-resistant strain fb322 resulted in putative recombinant strains capable of growth on lactate. analysis of total protein by sds-page and chromosomal dna by hybridization, indicated that the recombinants were derived from strain fb322. dna hybridization produced no evidence that plasmid transfer occurred, leaving chromosomal dna transfer as the ...19968588888
the role of ciliate protozoa in the lysis of methanogenic archaea in rumen fluid.predation by ciliate protozoa can account for 90% of the eubacterial protein turnover in the rumen. however, little is known about the factors affecting the lysis of archaea in rumen fluid. bacterial lysis was followed from the release of acid-soluble 14c from 14c leucine-labelled bacteria. the rumen methanogen methanobrevibacter mf1 was broken down more rapidly than other non-ruminal archaea in rumen fluid withdrawn from sheep harbouring either a mixed protozoa population or monofaunated with p ...19968987902
hexose phosphorylation by the ruminal bacterium selenomonas ruminantium.three strains of selenomonas ruminantium (d, ga192, and h18) were surveyed for phosphorylation of d-glucose and 2-deoxyglucose by phosphoenolpyruvate and atp. cells of all three strains that had been treated with toluene had high rates of hexose phosphorylation with either phosphoryl donor; this activity was constitutive in strain d. glucose phosphorylation that was dependent on phosphoenolpyruvate was maximal at ph 7.2, remained fairly high at ph 6.5, but decreased (> or = 65%) at ph 5.0 for al ...19968744219
influence of calcium concentration on the antimicrobial activity of lasalocid against selenomonas ruminantium.the present study was designed to examine the interaction between the effects of lasalocid and ca2+ on the growth and structure of selenomonas ruminantium hd-4. lasalocid, at a dose of 10 microm, inhibited cell growth almost completely after 12 hr incubation in the presence of relatively high extracellular concentrations of ca2+ (from 5 to 50 mm), but only slightly reduced cell growth in the presence of 0.2 mm ca2+. with ca2+ alone, cell growth was also inhibited at 12 hr as a function of the co ...19968877974
malate content of forage varieties commonly fed to cattle.the objective of this study was to determine the concentration of malate in forage varieties at different stages of maturity. five alfalfa varieties (alfagraze, apollo supreme cimarron, crockett, and magnum iii) and three bermudagrass varieties (coastal, tifton-78, and tifton-85) were collected at different stages of maturity. samples were collected from replicate plots (n = 3) of each alfalfa variety at 9, 18, 28, 35, and 42 d of maturity; bermudagrass hay samples were composited from six bales ...19979276804
factors affecting lactate and malate utilization by selenomonas ruminantium.lactate utilization by selenomonas ruminantium is stimulated in the presence of malate. because little information is available describing lactate-plus-malate utilization by this organism, the objective of this study was to evaluate factors affecting utilization of these two organic acids by two strains of s. ruminantium. when s. ruminantium hd4 and h18 were grown in batch culture on dl-lactate and dl-malate, both strains coutilized both organic acids for the initial 20 to 24 h of incubation and ...19979471965
effects of a saccharomyces cerevisiae culture on ruminal bacteria that utilize lactate and digest cellulose.the objective of this study was to determine the effects of a yeast (saccharomyces cerevisiae) culture on lactate utilization and cellulose digestion by ruminal bacteria. growth of selenomonas ruminantium hd4 in medium that contained 5 g/l of dl-lactate, trypticase, and yeast extract was stimulated 7 and 15% by 1 and 5% (vol/vol) yeast culture filtrate respectively. the 1 and 5% yeast culture filtrate stimulated growth of selenomonas ruminantium h18 and megasphaera elsdenii b159 and t81 on 5 g/l ...19979313145
effect of aspergillus oryzae extract alone or in combination with antimicrobial compounds on ruminal bacteria.the effect of an aspergillus oryzae fermentation extract on the growth rates of pure cultures of ruminal bacteria was determined. bacteria were grown in an anaerobic ruminal fluid and carbohydrate medium. a sterile filtrate made with 10% a. oryzae was added to the medium at 2 or 5% (vol/vol) to provide a final a. oryzae concentration of 2 or 5 mg/ml, respectively. the filtrate had no effect on the growth rates of 10 of the 19 ruminal bacteria tested; however, the filtrate increased the growth ra ...19989684165
phytase activity of anaerobic ruminal bacteria.phytase catalyses the release of phosphate from phytate (myo-inositol hexakisphosphate), the predominant form of phosphorus in cereal grains, oilseeds and legumes. the presence of phytase activity was investigated in 334 strains of 22 species of obligately anaerobic ruminal bacteria. measurable activities were demonstrated in strains of selenomonas ruminantium, megasphaera elsdenii, prevotella ruminicola, mitsuokella multiacidus and treponema spp. strains isolated from fermentations with cereal ...19989639927
de novo synthesis of amino acids by the ruminal bacteria prevotella bryantii b14, selenomonas ruminantium hd4, and streptococcus bovis es1.the influence of peptides and amino acids on ammonia assimilation and de novo synthesis of amino acids by three predominant noncellulolytic species of ruminal bacteria, prevotella bryantii b14, selenomonas ruminantium hd4, and streptococcus bovis es1, was determined by growing these bacteria in media containing 15nh4cl and various additions of pancreatic hydrolysates of casein (peptides) or amino acids. the proportion of cell n and amino acids formed de novo decreased as the concentration of pep ...19989687438
strategies that ruminal bacteria use to handle excess carbohydrate.when ruminal bacteria have insufficient nitrogen and other nutrients, excess carbohydrate can be toxic. pure cultures that are nitrogen-limited can convert only some of the excess carbohydrate to intracellular polysaccharide, but this pool can be quickly saturated. fibrobacter succinogenes cultures that have excess cellobiose secrete glucose and cellotriose into the culture medium, and prevotella ruminicola produces methylglyoxal, a highly toxic substance that causes a dramatic decrease in viabi ...19989690652
xylooligosaccharide utilization by the ruminal anaerobic bacterium selenomonas ruminantium.fermentation of xylooligosaccharides by 11 strains of selenomonas ruminantium was examined. xylooligosaccharides were prepared by the partial hydrolysis of oat spelt xylan in dilute phosphoric acid (50 mm, 121 degrees c, 15 min) and were added to a complex, yeast extract-trypticase-containing medium. strains of s. ruminantium varied considerably in their capacity to ferment xylooligosaccharides. strains ga192, ga31, h18, and d used arabinose, xylose, and the oligosaccharides xylobiose through xy ...19989504982
large plasmids in ruminal strains of selenomonas ruminantium.the plasmid content of six different isolates of selenomonas ruminantium from the rumen of sheep, cows or goats was examined by electron microscopy. in addition to small plasmids (< 12 kb) studied previously, all six strains contained at least one plasmid larger than 20 kb. plasmid sizes of 1.4, 2.1, 2.4, 5.0, 6.2, 20.4, 20.8, 22.7, 23.3, 29.3, 30.7, 34.4 and 42.6 kb were estimated from contour length measurements. dna-dna hybridization experiments revealed homology among the large plasmids from ...19989633087
lysogenic bacteriophage m1 from selenomonas ruminantium: isolation, characterization and dna sequence analysis of the integration site.bacteriophage m1 from the ruminal bacterium selenomonas ruminantium strain ml12 comprises a 30 nm icosahedral capsid, a 25 nm tail and 48 kb of linear dsdna with cohesive ends. a restriction map of the phage genome has been constructed. the presence of bacteriophage m1 in the rumen has been demonstrated by pcr amplification and southern blot analysis of dna from rumen bacterial samples obtained from ten different sheep. lysogeny was demonstrated by hybridization of m1 dna to host chromosomal dna ...19989720041
selenomonas lipolytica sp. nov., an obligately anaerobic bacterium possessing lipolytic activity.a novel, oligately anaerobic bacterium capable of hydrolysing lipids was isolated from a tropical anaerobic lagoon receiving waste water from an edible oil mill. the isolate had many characteristics similar to those of members of the genus selenomonas. the isolate showed lipolytic activity on tributyrin, triolein and groundnut oil in qualitative plate clearance assays, which has not been reported for the type strain of the genus selenomonas. it did not require n-valerate supplementation for grow ...19989734032
two restriction endonucleases in selenomonas ruminantium subsp. lactilytica.crude protein extract from a recently isolated ruminal bacterium identified as selenomonas ruminantium subsp. lactilytica specifically cleaved dna. this ability was due to the presence of two site-specific restriction endonucleases. sr/i, a naei schizomer, recognizes the 5'-gccggc-3' sequence. sr/ii, a nsii schizomer, recognizes 5'-atgcat-3'.19989750328
detection of n6-methyladenine in gatc sequences of selenomonas ruminantium.the presence of n6-methyladenine in gatc sequences in dna of selenomonas ruminantium was investigated using sensitive methylation discriminating isochizomeric restriction enzymes analysis. methylated adenine was detected in 8 out of 18 tested strains belonging to the subsp. lactilytica of s. ruminantium. no corresponding restriction activity was detected in three tested strains. no gatc methylation was detected in 3 analysed s. ruminantium subsp. ruminantium strains. sustainable progress was ach ...19989791949
effects of laidlomycin propionate and monensin on glucose utilization and nutrient transport by streptococcus bovis and selenomonas ruminantium.the objective of this study was to compare the effects of laidlomycin propionate and monensin on cell growth, glucose fermentation, and glucose uptake in streptococcus bovis strain jb1 and selenomonas ruminantium strain hd4. experiments were also conducted to compare the effects of both ionophores on sodium-dependent serine transport and cell yield in s. bovis. batch cultures (500 ml) of each bacterium were grown on 3.6 g/l d-glucose in semidefined medium and treated with either 5 ppm monensin o ...19989814916
manipulation of ruminal fermentation with organic acids: a review.the dicarboxylic acids aspartate, fumarate, and malate stimulate lactate utilization by the predominant ruminal bacterium, selenomonas ruminantium. malate stimulates lactate uptake by s. ruminantium more than does aspartate or fumarate, and it seems that malate and sodium are involved in stimulating lactate utilization by this bacterium. based on the ability of s. ruminantium to grow on malate in the presence of extracellular hydrogen and produce succinate, malate may be acting as an electron si ...19989928618
[the operative surgery of cancer of the tongue]. 1998106345
[seasonal changes in spermatozoas and fertility of stallions in the tropics].an attempt was made to express the relationship of spermiological characteristics with the fertility on the basis of seasonal variability of the fertility of stallions and of the ejaculate quality. a positive correlation between the activity of spermatozoa and the fertility ensues from the values of correlation coefficients. there is a negative correlation between the fertility and the concentration of citric acid. in the other characteristics, i.e. in the production of spermatozoa, volume of ge ...1998106512
dengue fever. 199819690
[effect of the prolonged administration of chlormadinone acetate on platelet function and blood chemistry with older male persons (author's transl)]. 199991459
gc-ms analysis of diaminopimelic acid stereoisomers and amino acid enantiomers in rumen bacteria.the amounts and the configuration of the stereoisomers of 2,6-diaminopimelic acid (dap) and the enantiomeric content of other amino acids were determined in five individual species (fibrobacter succinogenes, streptococcus bovis, selenomonas ruminantium, prevotella ruminicola and anaerovibrio lipolytica) of rumen bacteria, and in samples of mixed rumen bacteria isolated from sheep. the separation and quantification of the dap stereoisomers was achieved by gas chromatography (gc) of trifluoroacety ...199910191943
effect of the addition of fumarate on methane production by ruminal microorganisms in vitro.the effect of fumarate used as a feed additive on the reduction of methanogenesis in the rumen was evaluated by in vitro experiments. the addition of fumarate to the culture of mixed ruminal microorganisms that were fermenting hay powder and concentrate reduced methane production. most fumarate was metabolized to propionate, and a slight increase was noted in other volatile fatty acids. fumarate was utilized by mixed bacteria but not by mixed protozoa. fibrobacter succinogenes, selenomonas rumin ...199910212465
complete nucleotide sequence of a cryptic plasmid from the ruminal bacterium selenomonas ruminantium hd4 and identification of two predicted open reading frames.a cryptic plasmid (psr1) isolated from selenomonas ruminantium hd4 was previously cloned into the hindiii site of pbr322 and a restriction map was constructed using hindiii, clai, bamhi, and pvuii (s. a. martin and r. g. dean, appl. environ. microbiol. 55(12), 3035-3038, 1989). analysis of the nucleotide sequence of psr1 revealed two major open reading frames (orfs) located in the minus strand at different frames. analysis of orf-1 revealed that it has 325 amino acids with a predicted mw of 36,5 ...199910413665
novel characteristics of selenomonas ruminantium lysine decarboxylase capable of decarboxylating both l-lysine and l-ornithine.lysine decarboxylase (ldc; ec 4.1.1.18) of selenomonas ruminantium is a constitutive enzyme and is involved in the synthesis of cadaverine, which is an essential constituent of the peptidoglycan for normal cell growth. we purified the s. ruminantium ldc by an improved method including hydrophobic chromatography and studied the fine characteristics of the enzyme. kinetic study of ldc showed that s. ruminantium ldc decarboxylated both l-lysine and l-ornithine with similar km and the decarboxylase ...199910427692
evidence for recent intergeneric transfer of a new tetracycline resistance gene, tet(w), isolated from butyrivibrio fibrisolvens, and the occurrence of tet(o) in ruminal bacteria.we have previously reported high-frequency transfer of tetracycline resistance between strains of the rumen anaerobic bacterium butyrivibrio fibrisolvens. donor strains were postulated to carry two tcr genes, one of which is transferred on a novel chromosomal element. it is shown here that coding sequences within the non-transmissible gene in b. fibrisolvens 1.230 are identical to those of the streptococcus pneumoniae tet(o) gene. this provides the first evidence for genetic exchange between fac ...199911207718
prevalence of ctgcag recognizing restriction and modification systems in ruminal selenomonades.analysis of restriction and modification activities in natural population of selenomonas ruminantium have revealed the prevalence of ctgcag (pst i isoschizomers) recognizing restriction and/or modification systems in these bacteria. pst i isoschizomeric restriction endonucleases were detected in 4 out of 15 strains tested. in one strain, the pst i isoschizomeric restriction system was accompanied by another restriction and modification system recognizing gaattc sequence (eco ri isoschizomer). fo ...199916887660
sequence analysis of small cryptic plasmids isolated from selenomonas ruminantium s20.two small cryptic plasmids designated pone429 and pone430 were isolated from a rumen bacterium, selenomonas ruminantium s20. the complete sequence of pone429 was 2100 bp and contained one open reading frame (orf) of 201 amino acids. the sequence of pone430 had 1527 bp and one orf of 171 amino acids with the similarity of replication protein (rep protein) of pom1, psn2, and pim13 isolated from butyrivibrio fibrisolvens, staphylococcus aureus, and bacillus subtilis, respectively. in these plasmids ...19999871109
phylogenetic characterization of centipeda periodontii, selenomonas sputigena and selenomonas species by 16s rrna gene sequence analysis.the nearly complete 16s rrna gene sequences for oral gram-negative anaerobic motile bacteria, centipeda periodontii, selenomonas sputigena and selenomonas species (formerly s. sputigena type strain), were determined in order to unveil their relationship to other oral motile bacteria. to determine the phylogenetic characterization of these bacteria, their 16s rrna gene sequences were obtained and compared with those from the ribosomal sequence databases previously reported. the 16s rrna gene sequ ...199910464949
the ability of "low g + c gram-positive" ruminal bacteria to resist monensin and counteract potassium depletion.gram-negative ruminal bacteria with an outer membrane are generally more resistant to the feed additive, monensin, than gram-positive species, but some bacteria can adapt and increase their resistance. 16s rrna sequencing indicates that a variety of ruminal bacteria are found in the "low g + c gram-positive group," but some of these bacteria are monensin resistant and were previously described as gram-negative species (e.g., selenomonas ruminantium and megasphaera elsdenii). the activity of mone ...199910486059
identification of the amino acid residues conferring substrate specificity upon selenomonas ruminantium lysine decarboxylase.lysine decarboxylase (ldc, ec 4.1.1.18) from selenomonas ruminantium has decarboxylating activities towards both l-lysine and l-ornithine with similar k(m) and vmax. here, we identified four amino acid residues that confer substrate specificity upon s. ruminantium ldc and that are located in its catalytic domain. we have succeeded in converting s. ruminantium ldc to an enzyme with a preference in decarboxylating activity for l-ornithine when the four-residue of ldc were replaced by the correspon ...199910586514
activity and properties of fumarate reductase in ruminal bacteria.fumarate-reducing bacteria were sought from the main ruminal bacteria. fibrobacter succinogenes, selenomonas ruminantium subsp. ruminantium, selenomonas ruminantium subsp. lactilytica, and veillonella parvula reduced fumarate by using h(2) as an electron donor. ruminococcus albus, prevotella ruminicola, and anaerovibrio lipolytica consumed fumarate, although they did not oxidize h(2). of these bacteria, v. parvula, two strains of selenomonas, and f. succinogenes had a high capacity to reduce fum ...200012483585
characterization of a major envelope protein from the rumen anaerobe selenomonas ruminantium ob268.cell envelopes from the gram-negative staining but phylogenetically gram-positive rumen anaerobe selenomonas ruminantium ob268 contained a major 42 kda heat modifiable protein. a similarly sized protein was present in the envelopes of selenomonas ruminantium d1 and selenomonas infelix. sodium dodecyl sulfate polyacrylamide gel electrophoresis of triton x-100 extracted cell envelopes from s. ruminantium ob268 showed that they consisted primarily of the 42 kda protein. polyclonal antisera produced ...200010779865
deoxyribonuclease activity in selenomonas ruminantium, streptococcus bovis, and bacteroides ovatus.six selenomonas ruminantium strains (132c, jw13, srk1, 179f, 5521c1, and 5934e), streptococcus bovis jb1, and bacteroides ovatus v975 were examined for nuclease activity as well as the ability to utilize nucleic acids, ribose, and 2-deoxyribose. nuclease activity was detected in sonicated cells and culture supernatants for all bacteria except s. ruminantium jw13 and 179f sonicated cells. s. ruminantium strains were able to utilize several deoxyribonucleosides, while s. bovis jb1 and b. ovatus v9 ...200010915204
effects of thymol on ruminal microorganisms.thymol (5-methyl-2-isopropylphenol) is a phenolic compound that is used to inhibit oral bacteria. because little is known regarding the effects of this compound on ruminal microorganisms, the objective of this study was to determine the effects of thymol on growth and lactate production by the ruminal bacteria streptococcus bovis jb1 and selenomonas ruminantium hd4. in addition, the effect of thymol on the in vitro fermentation of glucose by mixed ruminal microorganisms was investigated. neither ...200011014870
gene cloning and molecular characterization of lysine decarboxylase from selenomonas ruminantium delineate its evolutionary relationship to ornithine decarboxylases from eukaryotes.lysine decarboxylase (ldc; ec 4.1.1.18) from selenomonas ruminantium comprises two identical monomeric subunits of 43 kda and has decarboxylating activities toward both l-lysine and l-ornithine with similar k(m) and v(max) values (y. takatsuka, m. onoda, t. sugiyama, k. muramoto, t. tomita, and y. kamio, biosci. biotechnol. biochem. 62:1063-1069, 1999). here, the ldc-encoding gene (ldc) of this bacterium was cloned and characterized. dna sequencing analysis revealed that the amino acid sequence ...200011073919
effect of sugars and malate on ruminal microorganisms.the objective of this study was to examine the effects of a commercial feed supplement that contains sugars and malate on lactate fermentation by selenomonas ruminantium grown in batch culture. experiments also were conducted to examine the effects of this feed supplement on the mixed ruminal microorganism fermentation of ground corn and soluble starch in the presence and absence of 5 mg/kg of monensin. when s. ruminantium strains hd4 and h18 were incubated in basal medium that contained dl-lact ...200011104277
highly conserved dna sequence present in small plasmids from selenomonas ruminantium.plasmid pjw1 from selenomonas ruminantium subsp. lactilytica strain jw13 has been cloned in escherichia coli vector pbluescriptsk(-) and completely sequenced. the plasmid is only 1410 bp with an overall gc content of 42.2%. computer analysis of sequence data revealed a single open reading frame (orf1, 146 amino acids, mw 16,525.5 da) encoding a putative replication protein which is similar to the rep protein of ruminobacter amylophilus plasmid prao1. orf1 is followed by a long at-rich (75%) regi ...200010873531
localization of phytase in selenomonas ruminantium and mitsuokella multiacidus by transmission electron microscopy.the localization of phytase (myo-inositol-hexaphosphate phosphohydrolase) in the ruminal bacteria, selenomonas ruminantium jy35 and mitsuokella multiacidus 46/5(2), was determined with transmission electron microscopy. phosphate produced from the enzymatic dephosphorylation of the calcium salt of phytic acid is precipitated as calcium phosphate. the calcium is then replaced with lead to produce electron-dense lead phosphate. this deposition of lead phosphate localized phytase in s. ruminantium j ...200010779878
effect of steroidal saponin from yucca schidigera extract on ruminal microbes.the effects of steroidal saponins (sap) isolated from yucca schidigera extract on ruminal bacteria and fungi were investigated in pure culture studies. prevotella bryantii, ruminobacter amylophilus, selenomonas ruminantium and streptococcus bovis were cultured through ten 24-h transfers in ruminal fluid medium containing 0 or 25 microg sap ml-1 (measured as smilagenin equivalents). the four strains, each non-exposed or pre-exposed to sap, were then inoculated into medium containing 0 or 250 micr ...200010792550
["information field dental health", an integral part of continuing dental education]. 200089765
effect of adrenergic receptor blockade on the responses to isometric handgrip: studies in normal and hypertensive subjects.heart rate and blood pressure (bp) responses to a standardized 3 min isometric handgrip (ihg) test were measured in 32 normotensive men and compared with those found in 35 age-matched, drug-free men with established essential hypertension (bp range: 140--170/90--110). ihg testing in the normal subjects induced significant increases in heart rate (mean +/- se: 7.6 +/- 3.3 beats/min), systolic blood pressure (19.4 +/- 5.3 mm hg), and diastolic blood pressure (15.6 +/- 4.6 mm hg). although beginnin ...200094394
mechanism of the interaction of desipramine with (na+, k+) atpase and p-nitrophenylphosphatase [proceedings]. 200192937
raised maternal serum-alpha-fetoprotein levels and spontaneous fetomaternal transfusion.study of blood smears showed that spontaneous fetomaternal transfusions were significantly more common among 42 pregnant women with raised serum-alpha-fetoprotein (afp) levels than among 45 pregnant women with normal serum-afp levels. raised serum-afp was associated with a spontaneous fetomaternal transfusion of greater than or equal to 0.1 ml in at least 21 of the 42 women in the study group.200192622
xanthine, hypoxanthine and muscle pain. histochemical and biochemical observations.a suspected case of xanthine oxidase deficiency has been further investigated. the patient complained of arthralgia and myalgia. further studies included histochemical and ultramicroscopic analysis of muscle sarcoplasmic reticulum, and biochemical studies. high levels of xanthine and hypoxanthine were found, while uric acid was absent in the muscle extracts.2001125457
restriction and modification systems of ruminal bacteria.a high frequency of type ii restriction endonuclease activities was detected in selenomonas ruminantium but not in other rumen bacteria tested. eight different restriction endonucleases were characterized in 17 strains coming from genetically homogeneous local population. chromosomal dna isolated from s. ruminantium strains was found to be refractory to cleavage by various restriction enzymes, implying the presence of methylase activities additional to those required for protection against the c ...200111501482
identification of a broad-specificity xylosidase/arabinosidase important for xylooligosaccharide fermentation by the ruminal anaerobe selenomonas ruminantium ga192.strains of selenomonas ruminantium vary considerably in their capacity to ferment xylooligosaccharides. this ability ranges from strain ga192, which completely utilized xylose through xylotetraose and was able to ferment considerable quantities of larger oligosaccharides, to strain hd4, which used only the simple sugars present in the hydrolysate. the ability of s. ruminantium ga192 to utilize xylooligosaccharides was correlated with the presence of xylosidase and arabinosidase activities. the p ...200111683366
a gene, coba + hemd, from selenomonas ruminantium encodes a bifunctional enzyme involved in the synthesis of vitamin b12.coenzymes derived from vitamin b12 (cyanocobalamin) are particularly important for core metabolism in ruminant animals. selenomonas ruminantium, a gram-positive obligate anaerobe isolated from cattle, is the main contributor of vitamin b12 to such ruminant animals. in nature, there are both aerobic and anaerobic pathways for b12 synthesis - the latter is only partly elucidated. until now, there has been no investigation of b12 synthesis in s. ruminantium, which must use an anaerobic pathway. thi ...200111750128
molecular characterization, enzyme properties and transcriptional regulation of phosphoenolpyruvate carboxykinase and pyruvate kinase in a ruminal bacterium, selenomonas ruminantium.to elucidate the regulatory mechanism for propionate production in selenomonas ruminantium, the molecular properties and gene expression of phosphoenolpyruvate carboxykinase (pck) and pyruvate kinase (pyk) were investigated. the pck was deduced to consist of 538 aa with a molecular mass of 59.6 kda, and appeared to exist as a monomer. the pyk was revealed to consist of four identical subunits consisting of 469 aa with a molecular mass of 51.3 kda. both mg(2+) and mn(2+) were required for the max ...200111238975
diet-dependent shifts in the bacterial population of the rumen revealed with real-time pcr.a set of pcr primers was designed and validated for specific detection and quantification of prevotella ruminicola, prevotella albensis, prevotella bryantii, fibrobacter succinogenes, selenomonas ruminantium-mitsuokella multiacida, streptococcus bovis, ruminococcus flavefaciens, ruminobacter amylophilus, eubacterium ruminantium, treponema bryantii, succinivibrio dextrinosolvens, and anaerovibrio lipolytica. by using these primers and the real-time pcr technique, the corresponding species in the ...200111375193
plasmids of selenomonas ruminantium and development of host-vector system.a high frequency of plasmids was detected in the rumen bacterium selenomonas ruminantium. plasmids 0.9-20 kb in size were detected in more than 50% tested strains. densitometric analysis indicated that plasmid dna could represents more than 25% of total cellular dna. up to six plasmids were detected in strain s. ruminantium 18. two smallest cryptic plasmids psrd181 and psrd182 from this strain were cloned into escherichia coli vector pbluescriptsk+ and partially characterized. the plasmid psrd18 ...200111830938
competition among three predominant ruminal cellulolytic bacteria in the absence or presence of non-cellulolytic bacteria.competition among three species of ruminal cellulolytic bacteria - fibrobacter succinogenes s85, ruminococcus flavefaciens fd-1 and ruminococcus albus 7 - was studied in the presence or absence of the non-cellulolytic ruminal bacteria selenomonas ruminantium or streptococcus bovis. co-cultures were grown under either batch or continuous conditions and populations were estimated using species-specific oligonucleotide probes to 16s rrna. the three cellulolytic species co-existed in cellobiose batc ...200111160797
allisonella histaminiformans gen. nov., sp. nov. a novel bacterium that produces histamine, utilizes histidine as its sole energy source, and could play a role in bovine and equine laminitis.when cattle and horses are fed large amounts of grain, histamine can accumulate in the gastrointestinal tract, and this accumulation can cause an acute inflammation of the hooves (laminitis). when ruminal fluid from dairy cattle fed grain supplements was serially diluted in anaerobic mrs medium containing histidine (50 mm), histamine was detected at dilutions as high as 10(-7). the histidine enrichments were then transferred successively in an anaerobic, carbonate-based medium (50 mm histidine) ...200212583709
a flavoprotein encoded in selenomonas ruminantium is characterized after expression in escherichia coli.selenomonas ruminantium is an obligate anaerobe that is very important for the provision of vitamin b12 to ruminants, which are particularly dependent upon this cofactor. one important use for vitamin b12 in anaerobic bacteria is for the utilization of glycerol as carbon source. a new flavoprotein has been found expressed by escherichia coli from a plasmid created as part of a gene library of s. ruminantium. the 2.5-kb fragment of chromosomal dna responsible for protein expression contains parts ...200211922759
identification of a 22-kda protein required for the degradation of selenomonas ruminantium lysine decarboxylase by atp-dependent protease.in selenomonas ruminantium, a strictly anaerobic, gram-negative bacterium isolated from sheep rumen, a rapid degradation of lysine decarboxylase (ldc) occurred on entry into the stationary phase of cell growth. here, we identified a 22-kda protein as a stimulating factor for the degradation of ldc, which was catalyzed by atp-dependent protease(s) in s. ruminantium. the purified 22-kda protein preparation itself had no degradation activity towards ldc but it was required for the degradation of ld ...200212162576
cloning of the l-lactate dehydrogenase gene from the ruminal bacterium selenomonas ruminantium hd4.a clone from a selenomonas ruminantium hd4 lambda zap ii genomic library was isolated by its ability to complement the anaerobic growth deficiency of an escherichia coli (pfl, ldh) double mutant. the 1.0-kb insert from the clone was sequenced and revealed a single open reading frame (orf, 957-bp) which was preceded by a putative shine-dalgarno (sd) sequence (aggggg). the potential sd sequence corresponded to 3' 16s rrna sequences of various selenomonas strains. the orf was predicted to encode a ...200211821921
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