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adhesion of cellulolytic ruminal bacteria to barley straw.adhesion of the cellulolytic ruminal bacteria ruminococcus flavefaciens and fibrobacter succinogenes to barley straw was measured by incubating bacterial suspensions with hammer-milled straw for 30 min, filtering the mixtures through sintered glass filters, and measuring the optical densities of the filtrates. maximum adhesion of both species occurred at ph 6.0 and during mid- to late-exponential phase. adhesion was saturable at 33 and 23 mg (dry weight) g of straw for r. flavefaciens and f. suc ...199016348278
characterization of egg yolk antibodies for detection and quantification of selenomonas ruminantium by using an enzyme-linked immunosorbent assay.the specificity of polyclonal antibodies prepared against strains of selenomonas ruminantium, the effect of assay conditions, and quantification of individual strains in mixed-cell suspensions of selenomonad strains were examined in this study. whole-cell suspensions were prepared with pure cultures of s. ruminantium pc18, hd(4), ga192, and d. each cell suspension was injected into a leghorn laying hen, and polyclonal antibodies were harvested from eggs laid in week 3 or 7 following initial immu ...199016348287
effect of dicarboxylic acids and aspergillus oryzae fermentation extract on lactate uptake by the ruminal bacterium selenomonas ruminantium.the objective of this study was to determine the effects of l-aspartate, fumarate, l-malate, and an aspergillus oryzae fermentation extract (amaferm) on growth on lactate as well as lactate uptake by selenomonas ruminantium hd4. growth of s. ruminantium in medium that contained 2 g of dl-lactate per liter was stimulated approximately twofold by 10 mm l-aspartate, fumarate, or l-malate after 24 h. both l-aspartate and fumarate increased lactate uptake over 4-fold, while l-malate stimulated uptake ...199016348354
characterization of a counterpart to mammalian ornithine decarboxylase antizyme in prokaryotes.the degradation of mammalian ornithine decarboxylase (odc) (ec 4.1.1.17) by 26 s proteasome, is accelerated by the odc antizyme (az), a trigger protein involved in the specific degradation of eukaryotic odc. in prokaryotes, az has not been found. previously, we found that in selenomonas ruminantium, a strictly anaerobic and gram-negative bacterium, a drastic degradation of lysine decarboxylase (ldc; ec 4.1.1.18), which has decarboxylase activities toward both l-lysine and l-ornithine with simila ...200616354653
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
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
spreading and mutability of selenomonas ruminantium plasmids.two small plasmids from selenomonas ruminantium strain 19d were cloned in escherichia coli and completely characterized. sequence comparison indicated that the plasmids are similar to those reported in genetically vaguely related s. ruminantium strain s20. small 1.4-kb plasmids psrd191 and pone430 are only distantly related (approximately 30 % for deduced rep protein amino acid sequence) but possess a short highly conserved region outside rep gene. larger plasmids psrd192 and pone429 possess lar ...200617007426
dominance of prevotella and low abundance of classical ruminal bacterial species in the bovine rumen revealed by relative quantification real-time pcr.relative quantification real-time pcr was used to quantify several bacterial species in ruminal samples from two lactating cows, each sampled 3 h after feeding on two successive days. abundance of each target taxon was calculated as a fraction of the total 16s rrna gene copies in the samples, using taxon-specific and eubacterial domain-level primers. bacterial populations showed a clear predominance of members of the genus prevotella, which comprised 42% to 60% of the bacterial rrna gene copies ...200717235560
kinetic and structural analysis of a bacterial protein tyrosine phosphatase-like myo-inositol polyphosphatase.phya from selenomonas ruminantium (phyasr), is a bacterial protein tyrosine phosphatase (ptp)-like inositol polyphosphate phosphatase (ippase) that is distantly related to known ptps. phyasr has a second substrate binding site referred to as a standby site and the p-loop (hcx5r) has been observed in both open (inactive) and closed (active) conformations. site-directed mutagenesis and kinetic and structural studies indicate phyasr follows a classical ptp mechanism of hydrolysis and has a broad sp ...200717567745
inhibition of the two-subsite beta-d-xylosidase from selenomonas ruminantium by sugars: competitive, noncompetitive, double binding, and slow binding modes.the active site of the gh43 beta-xylosidase from selenomonas ruminantium comprises two subsites and a single access route for ligands. steady-state kinetic experiments that included enzyme (e), inhibitory sugars (i and x) and substrate (s) establish examples of ei, eii, eix, and eis complexes. protonation states of catalytic base (d14, pk(a) 5) and catalytic acid (e186, pk(a) 7) govern formation of inhibitor complexes and strength of binding constants: e.g., eii, eix, and eis occur only with the ...200717588525
structure-function relationships of a catalytically efficient beta-d-xylosidase.beta-d-xylosidase from selenomonas ruminantium is revealed as the best catalyst known (kcat, kcat/km) for promoting hydrolysis of 1,4-beta-d-xylooligosaccharides. 1h nuclear magnetic resonance experiments indicate the family 43 glycoside hydrolase acts through an inversion mechanism on substrates 4-nitrophenyl- beta-d-xylopyranoside (4npx) and 1,4-beta-d-xylobiose (x2). progress curves of 4-nitrophenyl-beta-d-xylobioside, xylotetraose and xylohexaose reactions indicate that one residue from the ...200717625266
variation in relative substrate specificity of bifunctional beta-d-xylosidase/alpha-l-arabinofuranosidase by single-site mutations: roles of substrate distortion and recognition.to probe differential control of substrate specificities for 4-nitrophenyl-alpha-l-arabinofuranoside (4npa) and 4-nitrophenyl-beta-d-xylopyranoside (4npx), residues of the glycone binding pocket of gh43 beta-d-xylosidase/alpha-l-arabinofuranosidase from selenomonas ruminantium were individually mutated to alanine. although their individual substrate specificities (kcat/km)(4npx) and (kcat/km)(4npa) are lowered 330 to 280,000 fold, d14a, d127a, w73a, e186a, and h248a mutations maintain similar re ...200717689155
two segments in bacterial antizyme p22 are essential for binding and enhance degradation of lysine/ornithine decarboxylase in selenomonas ruminantium.in selenomonas ruminantium, a strictly anaerobic and gram-negative bacterium, the degradation of lysine/ornithine decarboxylase (ldc/odc) by atp-requiring protease(s) is accelerated by the binding of p22, which is a ribosomal protein of this strain. amino acid sequence alignment of s. ruminantium p22 with the l10 ribosomal proteins of gram-positive and -negative bacteria showed that p22 has a 5-residue k101nkld105 segment and an 11-residue g160virnavyvld170 segment, both of which are lacking in ...200817965150
the characterization of lactic acid producing bacteria from the rumen of dairy cattle grazing on improved pasture supplemented with wheat and barley grain.to identify and characterize the major lactic acid bacteria in the rumen of dairy cattle grazing improved pasture of rye grass and white clover and receiving a maize silage and grain supplement with and without virginiamycin.200818217928
occurrence of agmatine pathway for putrescine synthesis in selenomonas ruminatium.selenomonas ruminantium synthesizes cadaverine and putrescine from l-lysine and l-ornithine as the essential constituents of its peptidoglycan by a constitutive lysine/ornithine decarboxylase (ldc/odc). s. ruminantium grew normally in the presence of the specific inhibitor for ldc/odc, dl-alpha-difluoromethylornithine, when arginine was supplied in the medium. in this study, we discovered the presence of arginine decarboxylase (adc), the key enzyme in agmatine pathway for putrescine synthesis, i ...200818256468
a protein tyrosine phosphatase-like inositol polyphosphatase from selenomonas ruminantium subsp. lactilytica has specificity for the 5-phosphate of myo-inositol hexakisphosphate.although it is becoming well known that myo-inositol polyphosphates and the enzymes involved in their metabolism play a critical role in eukaryotic systems, little is understood of their significance in prokaryotic systems. a novel protein tyrosine phosphatase (ptp)-like inositol polyphosphatase (ippase) gene has been cloned from selenomonas ruminantium subsp. lactilytica (phyasrl). the deduced amino acid sequence of phyasrl is most similar to a ptp-like ippase from the anaerobic bacterium s. ru ...200818358762
structure of the two-subsite beta-d-xylosidase from selenomonas ruminantium in complex with 1,3-bis[tris(hydroxymethyl)methylamino]propane.the three-dimensional structure of the catalytically efficient beta-xylosidase from selenomonas ruminantium in complex with competitive inhibitor 1,3-bis[tris(hydroxymethyl)methylamino]propane (btp) was determined by using x-ray crystallography (1.3a resolution). most h bonds between inhibitor and protein occur within subsite -1, including one between the carboxyl group of e186 and an n group of btp. the other n of btp occupies subsite +1 near k99. e186 (pk(a) 7.2) serves as catalytic acid. the ...200818374656
beta-d-xylosidase from selenomonas ruminantium: catalyzed reactions with natural and artificial substrates.catalytically efficient beta-d-xylosidase from selenomonas ruminantium (sxa) exhibits pk (a)s 5 and 7 (assigned to catalytic base, d14, and catalytic acid, e186) for k (cat)/k (m) with substrates 1,4-beta-d-xylobiose (x2) and 1,4-beta-d-xylotriose (x3). catalytically inactive, dianionic sxa (d14(-)e186(-)) has threefold lower affinity than catalytically active, monoanionic sxa (d14(-)e186(h)) for x2 and x3, whereas d14(-)e186(-) has twofold higher affinity than d14(-)e186(h) for 4-nitrophenyl-be ...200818421594
beta-d-xylosidase from selenomonas ruminantium of glycoside hydrolase family 43.beta-d-xylosidase from the ruminal anaerobic bacterium, selenomonas ruminantium (sxa), catalyzes hydrolysis of beta-1,4-xylooligosacharides and has potential utility in saccharification processes. the enzyme, heterologously produced in escherichia coli and purified to homogeneity, has an isoelectric point of approx 4.4, an intact n terminus, and a stokes radius that defines a homotetramer. sxa denatures between ph 4.0 and 4.3 at 25 degrees c and between 50 and 60 degrees c at ph 5.3. following h ...200718478379
effect of ionic strength and oxidation on the p-loop conformation of the protein tyrosine phosphatase-like phytase, phyasr.the protein tyrosine phosphatase (ptp)-like phytase, phyasr, from selenomonas ruminantium is a novel member of the ptp superfamily, and the only described member that hydrolyzes myo-inositol-1,2,3,4,5,6-hexakisphosphate. in addition to the unique substrate specificity of phyasr, the phosphate-binding loop (p-loop) has been reported to undergo a conformational change from an open (inactive) to a closed (active) conformation upon ligand binding at low ionic strength. at high ionic strengths, the p ...200818573100
necessary corrections to the approved lists of bacterial names according to rule 40d (formerly rule 46). opinion 86.the judicial commission affirms that, according to rule 40d, formerly rule 46, of the bacteriological code, the authorship of a number of subspecies names included on the approved lists of bacterial names must be corrected. these names are acetobacter aceti subsp. aceti, acetobacter pasteurianus subsp. pasteurianus, bacteroides melaninogenicus subsp. melaninogenicus, campylobacter fetus subsp. fetus, mycobacterium chelonae subsp. chelonae, propionibacterium freudenreichii subsp. freudenreichii, ...200818676492
genetic variability of rumen selenomonads.molecular diversity of rumen bacteria belonging to the species selenomonas ruminantium was evaluated by biochemical and pcr analyses targeted at the 16s rrna operon and lactate dehydrogenase gene. while extremely variable in metabolic characteristics, two different risa (ribosomal intergenic spacer analysis), and five lactate dehydrogenase gene rflp profiles were observed among the twelve strains studied. the strains showed very limited variability ardra ( amplified ribosomal dna restriction ana ...200818837167
biotransformation of 2,4,6-trinitrotoluene by pure culture ruminal bacteria.twenty-one ruminal bacteria species were tested for their ability to degrade 2,4,6-trinitrotoluene (tnt) within 24 h. butyrivibrio fibrisolvens, fibrobacter succinogenes, lactobacillus vitulinus, selenomonas ruminantium, streptococcus caprinus, and succinivibrio dextrinosolvens were able to completely degrade 100 mg/l tnt, with <5% of the original tnt recovered as diaminonitrotoluene metabolites. eubacterium ruminantium, lactobacillus ruminis, ruminobacter amylophilus, streptococcus bovis, and w ...200918839246
beta-d-xylosidase from selenomonas ruminantium: thermodynamics of enzyme-catalyzed and noncatalyzed reactions.beta-d-xylosidase/alpha-l-arabinofuranosidase from selenomonas ruminantium is the most active enzyme known for catalyzing hydrolysis of 1,4-beta-d: -xylooligosaccharides to d-xylose. temperature dependence for hydrolysis of 4-nitrophenyl-beta-d-xylopyranoside (4npx), 4-nitrophenyl-alpha-l-arabinofuranoside (4npa), and 1,4-beta-d-xylobiose (x2) was determined on and off (k (non)) the enzyme at ph 5.3, which lies in the ph-independent region for k (cat) and k (non). rate enhancements (k (cat)/k (n ...200918953511
aminoalcohols as probes of the two-subsite active site of beta-d-xylosidase from selenomonas ruminantium.catalysis and inhibitor binding by the gh43 beta-xylosidase are governed by the protonation states of catalytic base (d14, pk(a) 5.0) and catalytic acid (e186, pk(a) 7.2) which reside in subsite -1 of the two-subsite active site. cationic aminoalcohols are shown to bind exclusively to subsite -1 of the catalytically-inactive, dianionic enzyme (d14(-)e186(-)). enzyme (e) and aminoalcohols (a) form e-a with the affinity progression: triethanolamine>diethanolamine>ethanolamine. e186a mutation raise ...200918973836
effects of the dicarboxylic acids malate and fumarate on e. coli o157:h7 and salmonella enterica typhimurium populations in pure culture and in mixed ruminal microorganism fermentations.the dicarboxylic acids malate and fumarate increase ruminal ph, reduce methane production, increase propionate and total volatile fatty acid (vfa) production, and reduce lactic acid accumulation in a manner similar to ionophores. these acids stimulate the ruminal bacterium selenomonas ruminantium to ferment lactate to produce propionate. thus, dicarboxylic acids have been suggested as nonantibiotic modifiers of the ruminal fermentation, but their impact on ruminal microbial ecology remains unkno ...200919194750
molecular and biochemical characterization of phosphoenolpyruvate carboxykinase in the ruminal bacterium ruminococcus albus.molecular properties and transcriptional control of phosphoenolpyruvate carboxykinase (pck; ec 4.1.1.32) in ruminococcus albus were examined. the putative 537-amino acid pck polypeptide has a predicted mass of 59.4 kda and an isoelectric point of 4.82. rt-pcr and northern blot analyses of pck mrna suggest that the transcript is monocistronic and that pck transcription is not affected by changes in sugar sources present in growth medium. pck enzymatic activity requires either mg(2+) or mn(2+) and ...200919194751
[isolation and in vitro metabolic characterization of a lactate-utilizing bacterium from goat rumen].a lactate-utilizing, propionate-producing bacterium, strain l9, was isolated from rumen of goat fed with high concentrate by utilizing modified hungate technique and anaerobic culture technique. the effect of the strain l9 culture on the rumen fermentation was further studied.200819271530
bacterial diversity in the rumen of gayals (bos frontalis), swamp buffaloes (bubalus bubalis) and holstein cow as revealed by cloned 16s rrna gene sequences.libraries of rumen bacterial 16s rrna gene sequences of gayals (bos frontalis) and swamp buffaloes (bubalus bubalis) were cloned and sequenced in the present work to compare the bacterial diversity with the third published library of holstein cow. sequence similarity of 97% was used as the definition of operational taxonomic unit (otu). the majority of the 470 sequences retrieved fell into the phyla of low g + c subdivision (329 sequences) and cytophaga-flexibacter-bacteroides (cfb, 123 sequence ...201019662514
dilution rates influence ammonia-assimilating enzyme activities and cell parameters of selenomonas ruminantium strain d in continuous (glucose-limited) culture.the objective of this study was to examine the effect of dilution rates (ds, varying from 0.05 to 0.42 h(-1)) in glucose-limited continuous culture on cell yield, cell composition, fermentation pattern and ammonia assimilation enzymes of selenomonas ruminantium strain d.201019702858
phylogenetic analysis of 16s rrna gene sequences reveals rumen bacterial diversity in yaks (bos grunniens).six matured male yaks (bos grunniens) with a mean live weight of 450 +/- 23 kg (mean +/- sd), were housed indoors in metabolism cages and fed pelleted lucerne (medicago sativum). after an adjustment period of 24 days of feeding the diet, samples of rumen content were obtained for analysis of the bacteria in the liquor. the diversity of rumen bacteria was investigated by constructing a 16s rrna gene clone library using the general bacterial primers f27 and r1492. a total of 130 clones, comprising ...201019757178
engineering lower inhibitor affinities in beta-d-xylosidase.beta-d-xylosidase catalyzes hydrolysis of xylooligosaccharides to d-xylose residues. the enzyme, sxa from selenomonas ruminantium, is the most active catalyst known for the reaction; however, its activity is inhibited by d-xylose and d-glucose (k (i) values of approximately 10(-2) m). higher k (i)'s could enhance enzyme performance in lignocellulose saccharification processes for bioethanol production. we report here the development of a two-tier high-throughput screen where the 1 degrees screen ...201019921178
beta-d-xylosidase from selenomonas ruminantium: role of glutamate 186 in catalysis revealed by site-directed mutagenesis, alternate substrates, and active-site inhibitor.beta-d-xylosidase/alpha-l-arabinofuranosidase from selenomonas ruminantium is the most active enzyme known for catalyzing hydrolysis of 1,4-beta-d-xylooligosaccharides to d-xylose. catalysis and inhibitor binding by the gh43 beta-xylosidase are governed by the protonation states of catalytic base (d14, pka 5.0) and catalytic acid (e186, pka 7.2). biphasic inhibition by triethanolamine of e186a preparations reveals minor contamination by wild-type-like enzyme, the contaminant likely originating f ...201020127424
properties and applications of microbial beta-d-xylosidases featuring the catalytically efficient enzyme from selenomonas ruminantium.xylan 1,4-beta-d-xylosidase catalyzes hydrolysis of non-reducing end xylose residues from xylooligosaccharides. the enzyme is currently used in combination with beta-xylanases in several large-scale processes for improving baking properties of bread dough, improving digestibility of animal feed, production of d-xylose for xylitol manufacture, and deinking of recycled paper. on a grander scale, the enzyme could find employment alongside cellulases and other hemicellulases in hydrolyzing lignocell ...201020352422
structural instability of small rolling circle replication plasmids from selenomonas ruminantium.the complete nucleotide sequence of psrd192 plasmid from selenomonas ruminantium 19d has been obtained and analyzed. the plasmid, 2334bp in length, was shown to replicate by rolling circle replication mechanism. by pcr method variability of psrd192-like plasmids was investigated and another variant of psrd192-like plasmid; the psrm22 plasmid 2338bp in length; was detected and characterized. both psrd192 and psrm22 plasmids share an identical rep gene and origins of replication to that of another ...201020450933
effects of hops (humulus lupulus l.) extract on volatile fatty acid production by rumen bacteria.to determine the effects of hops extract on in vitro volatile fatty acid (vfa) production by bovine rumen micro-organisms.201020456526
lactate dehydrogenase gene variability among predominant lactate utilizing ruminal bacteria.the inter- and intraspecies variability of lactate dehydrogenase (ldh) gene was determined among the predominant ruminal lactate utilizing bacteria. nearly complete nucleotide sequences of ldh gene, encoding nad-dependent lactate dehydrogenase of three megasphaera elsdenii and six selenomonas ruminantium strains, were obtained and compared. phylogenetic analyses revealed a limited variability between the ldh sequences studied. the majority of differences observed were silent mutations at the 3rd ...201020680561
bacterial composting of animal fleshing generated from tannery industries.animal fleshing (anfl) is the major proteinaceous solid waste generated during the manufacture of leather, which requires to be disposed of by environmentally sound manner. this study reports about the treatment of anfl into an organic compost and its effects on physiological parameters of different crops in a laboratory study. the anfl was hydrolysed using selenomonas ruminantium hm000123 and then the hydrolysed anfl was mixed with cow dung and leaf litter for producing composted organic fertil ...201020727727
cadaverine covalently linked to peptidoglycan is required for interaction between the peptidoglycan and the periplasm-exposed s-layer-homologous domain of major outer membrane protein mep45 in selenomonas ruminantium.the peptidoglycan of selenomonas ruminantium is covalently bound to cadaverine (pg-cadaverine), which likely plays a significant role in maintaining the integrity of the cell surface structure. the outer membrane of this bacterium contains a 45-kda major protein (mep45) that is a putative peptidoglycan-associated protein. in this report, we determined the nucleotide sequence of the mep45 gene and investigated the relationship between pg-cadaverine, mep45, and the cell surface structure. amino ac ...201020851903
rumen microbial population dynamics during adaptation to a high-grain diet.high-grain adaptation programs are widely used with feedlot cattle to balance enhanced growth performance against the risk of acidosis. this adaptation to a high-grain diet from a high-forage diet is known to change the rumen microbial population structure and help establish a stable microbial population within the rumen. therefore, to evaluate bacterial population dynamics during adaptation to a high-grain diet, 4 ruminally cannulated beef steers were adapted to a high-grain diet using a step-u ...201020851965
the effect of replacing corn with glycerol on ruminal bacteria in continuous culture fermenters.the effects of substituting corn with glycerol on dna concentration of selected ruminal bacteria were investigated using continuous fermenters. four continuous culture fermenters were used in a 4 × 4 latin square design with four 10 days consecutive periods. treatment diets (60:40 forage to concentrate) were fed at 45 g/day dry matter (dm) in three equal portions. glycerol (0.995 g/g glycerol) was used to replace corn in a grain mix at proportions of 0% (t0; control), 15% (t15), 30% (t30) and 45 ...201020880288
characterization of lateral flagella of selenomonas ruminantium.selenomonas ruminantium produces a tuft of flagella near the midpoint of the cell body and swims by rotating the cell body along the cell's long axis. the flagellum is composed of a single kind of flagellin, which is heavily glycosylated. the hook length of s. ruminantium is almost double that of salmonella.201121335384
cadaverine covalently linked to the peptidoglycan serves as the correct constituent for the anchoring mechanism between the outer membrane and peptidoglycan in selenomonas ruminantium.in selenomonas ruminantium, a strictly anaerobic and gram-negative bacterium, cadaverine covalently linked to the peptidoglycan is required for the interaction between the peptidoglycan and the s-layer homologous (slh) domain of the major outer membrane protein mep45. here, using a series of diamines with a general structure of nh(3)(+)(ch(2))(n)nh(3)(+) (n = 3 to 6), we found that cadaverine (n = 5) specifically serves as the most efficient constituent of the peptidoglycan in acquiring the high ...201121398553
engineering lower inhibitor affinities in β-d: -xylosidase of selenomonas ruminantium by site-directed mutagenesis of trp145.β-d: -xylosidase/α-l: -arabinofuranosidase from selenomonas ruminantium is the most active enzyme reported for catalyzing hydrolysis of 1,4-β-d: -xylooligosaccharides to d: -xylose. one property that could use improvement is its relatively high affinities for d: -glucose and d: -xylose (k (i) ~ 10 mm), which would impede its performance as a catalyst in the saccharification of lignocellulosic biomass for the production of biofuels and other value-added products. previously, we discovered that th ...201121528413
the effect of lipid supplements on ruminal bacteria in continuous culture fermenters varies with the fatty acid composition.a single flow continuous culture fermenter system was used in this study to investigate the influence of dietary lipid supplements varying in their fatty acid content on the dna concentration of selected rumen bacteria. four continuous culture fermenters were used in a 4×4 latin square design with four periods of 10 d each. treatment diets were fed at 45 g/d (dm basis) in three equal portions during the day. the diets were: 1) control (con), 2) control with animal fat source (sat), 3) control wi ...201121538241
Impact of subacute ruminal acidosis (SARA) adaptation and recovery on the density and diversity of bacteria in the rumen of dairy cows.Subacute ruminal acidosis (SARA) is characterized by ruminal pH depression and microbial perturbation. The impact of SARA adaptation and recovery on rumen bacterial density and diversity was investigated following high-grain feeding. Four ruminally cannulated dairy cows were fed a hay diet, transitioned to a 65% grain diet for 3 weeks, and returned to the hay diet for 3 weeks. Rumen fluid, rumen solids, and feces were sampled during weeks 0 (hay), 1 and 3 (high grain), and 4 and 6 (hay). SARA wa ...201121692816
populations of select cultured and uncultured bacteria in the rumen of sheep and the effect of diets and ruminal fractions.the objective of this study was to assess the importance of select cultured and uncultured bacteria in the rumen by quantifying their populations and the effect of diets and ruminal fractions. full-length 16s rrna gene (rrs) sequences were recovered from rumen samples using specific primers designed from partial sequences recovered previously. five uncultured bacterial operational taxonomic units (otus) were quantified using specific quantitative pcr (qpcr) in fractionated ruminal samples from s ...201121822435
Evidence for the possible involvement of Selenomonas ruminantium in rumen fiber digestion.Selenomonas ruminantium strains were isolated from sheep rumen, and their significance for fiber digestion was evaluated. Based on the phylogenetic classification, two clades of S. ruminantium (clades I and II) were proposed. Clade II is newly found, as it comprised only new isolates that were phylogenetically distant from the type strain, while all of the known isolates were grouped in the major clade I. More than half of clade I isolates displayed CMCase activity with no relation to the degree ...201122092507
Substrate binding in protein tyrosine phosphatase-like inositol polyphosphatases.Protein-tyrosine phosphatase-like inositol polyphosphatases are microbial enzymes that catalyze the stepwise removal of one or more phosphates from highly phosphorylated myo-inositols via a relatively ordered pathway. In order to understand the substrate specificity and kinetic mechanism of these enzymes we have determined high resolution, single crystal, X-ray crystallographic structures of inactive Selenomonas ruminantium phyA in complex with myo-inositol hexa- and penta-kisphosphate. These ...201122139834
Critical cellulase and hemicellulase activities for hydrolysis of ionic liquid pretreated biomass.Critical cellulase and hemicellulase activities are identified for hydrolysis of ionic liquid (IL) pretreated poplar and switchgrass; hemicellulase rich substrates with largely amorphous cellulose. Enzymes from Aspergillus nidulans were expressed and purified: an endoglucanase (EG) a cellobiohydrolase (CBH), an endoxylanase (EX) and an acetylxylan esterase (AXE). ß-Xylosidase (ßX) from Selenomonas ruminantium and a commercial ß-glucosidase (ßG) from Novozyme 188 were admixed with the A. nidulans ...201222154300
the correlation between composition of the bacterial community and concentration of volatile fatty acids in the rumen during the transition period and ketosis in dairy cows.the transition period is a severe challenge to dairy cows. glucose supply cannot meet demand and body fat is mobilized, potentially leading to negative energy balance (neb), ketosis or fatty liver. propionate produces glucose by gluconeogenesis, which generation depends heavily on the number and species of microbes. in present study we analyzed the rumen microbiome composition of cows in the transition period, cows with ketosis and non-perinatal cows using terminal restriction fragment length po ...201222267666
a fibrolytic enzyme additive for lactating holstein cow diets: ruminal fermentation, rumen microbial populations, and enteric methane emissions.the objective was to determine if supplementing a dairy cow diet with an exogenous fibrolytic enzyme additive (econase rde; ab vista, marlborough, wiltshire, uk) altered fermentation, ph, and microbial populations in the rumen or enteric methane (ch(4)) emissions. in a companion study, this enzyme additive improved efficiency of fat-corrected milk production in a dose-dependent manner by up to 11% for early lactation dairy cows. nine ruminally cannulated, lactating holstein cows were used in a r ...201222365224
characterization of rumen bacterial diversity and fermentation parameters in concentrate fed cattle with and without forage.to determine the effects of the removal of forage in high-concentrate diets on rumen fermentation conditions and rumen bacterial populations using culture-independent methods.201222533638
effect of disodium fumarate on microbial abundance, ruminal fermentation and methane emission in goats under different forage: concentrate ratios.this study investigated the effects of disodium fumarate (df) on methane emission, ruminal fermentation and microbial abundance in goats under different forage (f) : concentrate (c) ratios and fed according to maintenance requirements. four ruminally fistulated, castrated male goats were used in a 4 × 4 latin square design with a 2 × 2 factorial arrangement of treatments and the main factors being the f : c ratios (41 : 59 or 58 : 42) and df supplementation (0 or 10 g/day). df reduced methane pr ...201222717128
effects of an extract of plant flavonoids (bioflavex) on rumen fermentation and performance in heifers fed high-concentrate diets.to study the effects of an extract of plant flavonoids [bioflavex (fl)] in cattle fed high-concentrate diets, 2 experiments were designed. in the first experiment, the effects of bioflavex on the development of rumen acidosis was evaluated in 8 holstein-friesian crossbreed heifers (451 kg; sem 14.3 kg of bw) using a crossover design. each experimental period lasted 22 d; from d 1 to 20, the animals were fed rye grass, on d 21 the animals were fasted, and on d 22, rumen acidosis was induced by ap ...201222829622
involvement of recently cultured group u2 bacterium in ruminal fiber digestion revealed by coculture with fibrobacter succinogenes s85.in a previous study, we reported the ecological significance of uncultured bacterial group u2 in the rumen. in this study, the involvement of a recently cultured group u2 bacterium, strain r-25, in fiber digestion was tested in coculture with the fibrolytic bacterium fibrobacter succinogenes s85. dry matter (dm) digestion, growth and metabolites were examined in culture using rice straw as the carbon source. although strain r-25 did not digest rice straw in monoculture, coculture of strain r-25 ...201222849722
molecular basis for the maintenance of envelope integrity in selenomonas ruminantium: cadaverine biosynthesis and covalent modification into the peptidoglycan play a major role.polyamine is a small organic polycation composed of a hydrocarbon backbone with multiple amino groups which ubiquitously exists in all living organisms from bacteria to higher animals. the critical step of polyamine biosynthesis generally includes the amino acid-decarboxylating reaction to produce the primary diamines, such as a synthesis of putrescine (nh(3)(+)·(ch(2))(4)·nh(3)(+)) from ornithine, and cadaverine (nh(3)(+)·(ch(2))(5)·nh(3)(+)) from lysine, which are catalyzed by pyridoxal-5'-pho ...201222878384
variability of putative rep gene cassettes in selenomonas ruminantium plasmids.characteristic feature of the most of selenomonas ruminantium cryptic plasmids is the presence of short, conserved sequences encompassing the gene for replication protein creating a potential rep gene cassette. pcr-based experiment was designed to analyse the genetic organization of putative plasmid rep modules and to assess s. ruminantium plasmid biodiversity. analysed pcr amplicons contained single open reading frames encoding for putative replication proteins. while most of the derived protei ...201222900647
mitigation of methane production from cattle by feeding cashew nut shell liquid.the effects of cashew nut shell liquid (cnsl) feeding on methane production and rumen fermentation were investigated by repeatedly using 3 holstein nonlactating cows with rumen fistulas. the cows were fed a concentrate and hay diet (6:4 ratio) for 4 wk (control period) followed by the same diet with a cnsl-containing pellet for the next 3 wk (cnsl period). two trials were conducted using cnsl pellets blended with only silica (trial 1) or with several other ingredients (trial 2). each pellet type ...201222916936
an efficient biosurfactant-producing bacterium selenomonas ruminantium ct2, isolated from mangrove sediment in south of thailand.biosurfactant-producing bacteria, isolate ct2, was isolated from mangrove sediment in the south of thailand. the sequence of the 16s rrna gene from isolate ct2 showed 100 % similarity with selenomonas ruminantium. the highest biosurfactant production (5.02 g/l) was obtained when the cells were grown on minimal salt medium containing 15 g/l molasses and 1 g/l commercial monosodium glutamate supplemented with 1 g/l nacl, 0.1 g/l leucine, 5 % (v/v) inoculum size at 30 °c and 150 rpm after 54 h of c ...201322932808
effect of non-starch-polysaccharide-degrading enzymes as feed additive on the rumen bacterial population in non-lactating cows quantified by real-time pcr.the effects of non-starch-polysaccharide-degrading enzymes, added to a maize silage- and grass silage-based total mixed ration (tmr) at least 14 h before feeding, on the rumen bacterial population were investigated. six non-lactating holstein friesian cows were allocated to three treatment groups using a duplicate 3 × 3 latin square design with three 31-day periods (29 days of adaptation and 2 days of sampling). treatments were control tmr [69% forage and 31% concentrates on a dry matter (dm) ba ...201323216628
effects of extracts of humulus lupulus (hops) and yucca schidigera applied alone or in combination with monensin on rumen fermentation and microbial populations in vitro.β-acids in hops (humulus lupulus) and saponins in yucca (yucca schidigera) have been found to possess antimicrobial properties similar to that of monensin and could be an alternative to in-feed antibiotics. the effects of monensin (mon) and ethanol extracts of hops (he) and y. schidigera (ye) alone and in combination with mon were assessed on ruminal microbial composition and fermentation in vitro of a barley-based diet.201323483574
effects of vanillin, quillaja saponin, and essential oils on in vitro fermentation and protein-degrading microorganisms of the rumen.this study investigated the effects of vanillin on methanogenesis and rumen fermentation, and the responses of ruminal protein-degrading bacteria to vanillin (at concentrations of 0, 0.76 and 1.52 g/l), essential oils (clove oil, 1 g/l; origanum oil, 0.50 g/l, and peppermint oil, 1 g/l), and quillaja saponin (at concentration of 0 and 6 g/l) in vitro. methane production, degradabilities of feed substrate, and ammonia concentration decreased linearly with increasing doses of vanillin. concentrati ...201423624710
two rep genes in small cryptic plasmid pkst21 of escherichia coli.the complete nucleotide sequence of a small cryptic plasmid pkst21 from escherichia coli was determined. this plasmid is 1,460 bp long with an overall gc content of 51 %. based on sequence analysis, the presence of two segments with different average gc density was observed. the segment with higher gc content revealed 98-90 % similarity to several small plasmids of e. coli and to pcr1 from gram-positive corynebacterium renale. plasmid pkst21 possesses two conversely oriented open reading frames ...201323680975
comparative evaluation of rumen metagenome community using qpcr and mg-rast.microbial profiling of metagenome communities have been studied extensively using mg-rast and other related metagenome annotation databases. although, database based taxonomic profiling provides snapshots of the metagenome architecture, their reliability needs to be validated through more accurate methods. here, we performed qpcr based absolute quantitation of selected rumen microbes in the liquid and solid fraction of the rumen fluid of river buffalo adapted to varying proportion of concentrate ...201324025701
use of real-time pcr technique in determination of major fibrolytic and non fibrolytic bacteria present in indian surti buffaloes (bubalus bubalis).in the milk industry in india, buffalo breeds are most commonly used for milk production. efficiency of fiber digestion in ruminants is critical for animal productivity. bacteria play an important role in fiber digestion and utilization. absolute quantification real-time pcr was used to quantify ten bacterial species in rumen fluid of surti buffalo fed green fodder, dry roughage and compound concentrate mixture. abundance of each target taxon was calculated as a fraction of the total 16s rrna ge ...201324053023
interaction of rumen bacteria as assumed by colonization patterns on untreated and alkali-treated rice straw.colonization patterns of representative rumen bacteria were compared between untreated rice straw (uts) and sodium hydroxide-treated rice straw (shts). uts and shts were incubated in the rumen of sheep for 10 min, 1, 2, 6, 12, 24, 48 and 96 h using the nylon bag method. the population sizes of 13 representative bacterial species or groups were quantified by real-time pcr. the total bacterial population size (abundance) was similar in both uts and shts. fibrobacter succinogenes showed a higher po ...201424612258
efficient production of mutant phytase (phya-7) derived from selenomonas ruminantium using recombinant escherichia coli in pilot scale.a mutant gene of rumen phytase (phya-7) was cloned into pet23b(+) vector and expressed in the escherichia coli bl21 under the control of the t7 promoter. the study of fermentation conditions includes the temperature impacts of mutant phytase expression, the effect of carbon supplements over induction stage, the inferences of acetic acid accumulation upon enzyme expression and the comparison of one-stage and two-stage operations in batch mode. the maximum value of phytase activity was reached 107 ...201424686155
effect of saccharomyces cerevisiae on alfalfa nutrient degradation characteristics and rumen microbial populations of steers fed diets with different concentrate-to-forage ratios.live yeast (saccharomyces cerevisiae) constitutes an effective additive for animal production; its probiotic effect may be related to the concentrate-to-forage ratio (ctfr). the objective of this study was to assess the effects of s. cerevisiae (sc) on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary concentrate. ten simmental × local crossbred steers (450 ± 50 kg bw) were assigned to a control group or an sc group. both groups were fed the s ...201424883184
development of a species-specific pcr assay for identification of the strictly anaerobic bacterium selenomonas lacticifex found in biofilm-covered surfaces in brewery bottling halls.in recent years, beer-spoilage cases from strictly anaerobic bacteria have risen in frequency, in connection with the production of non-pasteurized, non-alcohol and low-alcoholic beers and with the lowering of dissolved oxygen in the packaged beer. selenomonas lacticifex, found in brewer's yeast and in biofilms covering some surfaces in brewery bottling area, is considered to be a beer-spoilage organism. this study aims to develop s. lacticifex-specific pcr assay. the objective of this study was ...201425066481
characterization of rumen bacterial strains isolated from enrichments of rumen content in the presence of propolis.propolis presents many biological properties, including antibacterial activities, and has been proposed as an additive in ruminant nutrition. twenty bacterial strains, previously isolated from enrichments of brazilian cow rumen contents in the presence of different propolis extracts (llos), were characterized using phenotyping and 16s rrna identification. seven strains were assigned to streptococcus sp., most likely s. bovis, and were all degrading starch. one amylolytic lactate-utilizing strain ...201425172217
influence of fermented tannery solid waste on morphological, biochemical, yield and nutritional responses of tomato plants.the non-tanned proteinaceous tannery solid waste animal fleshing (anfl), containing high nutritive value, was hydrolyzed using bacteria selenomonas ruminantium hm000123 through submerged (smf) and solid-state (ssf) fermentation processes. in addition, the effects of anfl fermentative hydrolysate on growth, yield and biochemical properties of tomato plants were investigated. the treatments included t1 (smf-anfl), t2 (ssf-anfl), t3 (recommended dose of npk fertilizers) and a control without any am ...201525296938
monitoring of gene expression in fibrobacter succinogenes s85 under the co-culture with non-fibrolytic ruminal bacteria.fibrobacter succinogenes is one of the most pivotal fibrolytic bacterial species in the rumen. in a previous study, we confirmed enhancement of fiber digestion in a co-culture of f. succinogenes s85 with non-fibrolytic ruminal strains r-25 and/or selenomonas ruminantium s137. in the present study, mrna expression level of selected functional genes in the genome of f. succinogenes s85 was monitored by real-time rt-pcr. growth profile of f. succinogenes s85 was similar in both the monoculture and ...201525354721
effect of ethanol and methanol on growth of ruminal bacteria selenomonas ruminantium and butyrivibrio fibrisolvens.the effect of ethanol and methanol on growth of several ruminal bacterial strains was examined. ethanol concentrations as low as 0.2% had a significant, but moderate, inhibitory effect on lag time or growth over time and 3.3% ethanol significantly inhibited maximum optical density obtained by both selenomonas ruminantium and butyrivibrio fibrisolvens. little growth of either strain occurred at 10% ethanol concentrations. methanol concentrations below 0.5% had little effect on either growth or ma ...201525421629
effects of nitrate addition to a diet on fermentation and microbial populations in the rumen of goats, with special reference to selenomonas ruminantium having the ability to reduce nitrate and nitrite.this study investigated the effects of dietary nitrate addition on ruminal fermentation characteristics and microbial populations in goats. the involvement of selenomonas ruminantium in nitrate and nitrite reduction in the rumen was also examined. as the result of nitrate feeding, the total concentration of ruminal volatile fatty acids decreased, whereas the acetate : propionate ratio and the concentrations of ammonia and lactate increased. populations of methanogens, protozoa and fungi, as esti ...201525439583
effect of soybean meal and soluble starch on biogenic amine production and microbial diversity using in vitro rumen fermentation.this study was conducted to investigate the effect of soybean meal (sm) and soluble starch (ss) on biogenic amine production and microbial diversity using in vitro ruminal fermentation. treatments comprised of incubation of 2 g of mixture (expressed as 10 parts) containing different ratios of sm to ss as: 0:0, 10:0, 7:3, 5:5, 3:7, or 0:10. in vitro ruminal fermentation parameters were determined at 0, 12, 24, and 48 h of incubation while the biogenic amine and microbial diversity were determined ...201525557675
study of rumen metagenome community using qpcr under different diets.the aim of this study was to detect the major bacteria present in rumen microbiota. here, we performed qpcr based absolute quantitation of selected rumen microbes in rumen fluid of river buffalo adapted to varying proportion of concentrate to roughage diets. animals were adapted to roughage-to-concentrate ratio in the proportion of 100:00 (t1), 75:25 (t2), 50:50 (t3) and 25:75 (t4) respectively for 30 days. at the end of each treatment, rumen fluid was collected at 0 h and 2 h after feeding. it ...201425606402
complete genome sequence of selenomonas ruminantium subsp. lactilytica will accelerate further understanding of the nature of the class negativicutes.selenomonas ruminantium subsp. lactilytica, a strictly anaerobic ruminal bacterium, possesses typical gram-negative cell surface structure comprising cytoplasmic membrane, peptidoglycan layer and outer membrane, whereas its 16s rrna-based taxonomy shows that the bacteria belongs to gram-positive firmicutes. complete genome analysis showed that genes or gene clusters involved in gram-negative cell structure were scattered in the s. ruminantium genome, and might provide the new insight of phylogen ...201525837814
rapid changes in key ruminal microbial populations during the induction of and recovery from diet-induced milk fat depression in dairy cows.the ruminant provides a powerful model for understanding the temporal dynamics of gastrointestinal microbial communities. diet-induced milk fat depression (mfd) in the dairy cow is caused by rumen-derived bioactive fatty acids, and is commonly attributed to the changes in the microbial population. the aim of the present study was to determine the changes occurring in nine ruminal bacterial taxa with well-characterised functions, and abundance of total fungi, ciliate protozoa and bacteria during ...201526123320
effects of nitrate addition on rumen fermentation, bacterial biodiversity and abundance.this study examined changes of rumen fermentation, ruminal bacteria biodiversity and abundance caused by nitrate addition with ion torrent sequencing and real-time polymerase chain reaction. three rumen-fistulated steers were fed diets supplemented with 0%, 1%, and 2% nitrate (dry matter %) in succession. nitrate supplementation linearly increased total volatile fatty acids and acetate concentration obviously (p = 0.02; p = 0.02; p<0.01), butyrate and isovalerate concentration numerically (p = 0 ...201526194220
divergent utilization patterns of grass fructan, inulin, and other nonfiber carbohydrates by ruminal microbes.fructans are an important nonfiber carbohydrate in cool season grasses. their fermentation by ruminal microbes is not well described, though such information is needed to understand their nutritional value to ruminants. our objective was to compare kinetics and product formation of orchardgrass fructan (phlein; phl) to other nonfiber carbohydrates when fermented in vitro with mixed or pure culture ruminal microbes. studies were carried out as randomized complete block designs. all rates given ar ...201626601577
nitrate and inhibition of ruminal methanogenesis: microbial ecology, obstacles, and opportunities for lowering methane emissions from ruminant livestock.ruminal methane production is among the main targets for greenhouse gas (ghg) mitigation for the animal agriculture industry. many compounds have been evaluated for their efficacy to suppress enteric methane production by ruminal microorganisms. of these, nitrate as an alternative hydrogen sink has been among the most promising, but it suffers from variability in efficacy for reasons that are not understood. the accumulation of nitrite, which is poisonous when absorbed into the animal's circulat ...201626904008
changes in rumen microbial community composition during adaption to an in vitro system and the impact of different forages.this study examined ruminal microbial community composition alterations during initial adaption to and following incubation in a rumen simulation system (rusitec) using grass or corn silage as substrates. samples were collected from fermenter liquids at 0, 2, 4, 12, 24, and 48 h and from feed residues at 0, 24, and 48 h after initiation of incubation (period 1) and on day 13 (period 2). microbial dna was extracted and real-time qpcr was used to quantify differences in the abundance of protozoa, ...201626928330
cloning and high-level expression of β-xylosidase from selenomonas ruminantium in pichia pastoris by optimizing of ph, methanol concentration and temperature conditions.β-xylosidase and several other glycoside hydrolase family members, including xylanase, cooperate together to degrade hemicelluloses, a commonly found xylan polymer of plant-cell wall. β-d-xylosidase/α-l-arabinofuranosidase from the ruminal anaerobic bacterium selenomonas ruminantium (sxa) has potential utility in industrial processes such as production of fuel ethanol and other bioproducts. the optimized synthetic sxa gene was overexpressed in methylotrophic pichia pastoris under the control of ...201627154901
peptidoglycan-associated outer membrane protein mep45 of rumen anaerobe selenomonas ruminantium forms a non-specific diffusion pore via its c-terminal transmembrane domain.the major outer membrane protein mep45 of selenomonas ruminantium, an anaerobic gram-negative bacterium, comprises two distinct domains: the n-terminal s-layer homologous (slh) domain that protrudes into the periplasm and binds to peptidoglycan, and the remaining c-terminal transmembrane domain, whose function has been unknown. here, we solubilized and purified mep45 and characterized its function using proteoliposomes reconstituted with mep45. we found that mep45 forms a nonspecific diffusion c ...201627310312
parameters of fermentation and rumen microbiota of nellore steers fed with different proportions of concentrate in fresh sugarcane containing diets.the objective of this study was to evaluate the effect of a fresh sugarcane-based diet and different roughage-to-concentrate ratios (70:30, 60:40, 40:60 and 20:80) on the rumen microbiota associated with rumen fermentation parameters and the intake and apparent digestibility of nutrients in nellore steers. eight rumen-cannulated nellore steers (331 ± 8 kg bw) were distributed in a double 4 × 4 latin square design balanced for the control of the residual effect. the ruminal ph decreased (p < 0.01 ...201627415825
effects of corn silage and grass silage in ruminant rations on diurnal changes of microbial populations in the rumen of dairy cows.here, we examined diurnal changes in the ruminal microbial community and fermentation characteristics of dairy cows fed total mixed rations containing either corn silage (cs) or grass silage (gs) as forage. the rations, which consisted of 52% concentrate and 48% gs or cs, were offered for ad libitum intake over 20 days to three ruminal-fistulated lactating jersey cows during three consecutive feeding periods. feed intake, ruminal ph, concentrations of short chain fatty acids and ammonia in rumen ...201627451293
shifts in rumen fermentation and microbiota are associated with dissolved ruminal hydrogen concentrations in lactating dairy cows fed different types of carbohydrates.different carbohydrates ingested greatly influence rumen fermentation and microbiota and gaseous methane emissions. dissolved hydrogen concentration is related to rumen fermentation and methane production.201627511925
engineering disulfide bonds in selenomonas ruminantium β-xylosidase by experimental and computational methods.homotetrameric β-xylosidase from selenomonas ruminantium (sxa) is one of the most efficient enzymes known for the hydrolysis of cell wall hemicellulose. sxa shows a rapid rate of activity loss at temperatures above 50°c. in this study, we have introduced two inter-subunit disulfide bridges with one point mutation. lys237 was chosen to be replaced with cysteine since it interacts with the same residue in the opposite subunit. while ph optimum, temperature profile and catalytic efficiency of the m ...201727818293
effects of the dose and viability of saccharomyces cerevisiae. 1. diversity of ruminal microbes as analyzed by illumina miseq sequencing and quantitative pcr.this study was conducted to examine effects of the dose and viability of supplemental saccharomyces cerevisiae on the ruminal fermentation and bacteria population and the performance of lactating dairy cows. four ruminally cannulated lactating cows averaging 284±18d in milk were assigned to 4 treatments arranged in a 4×4 latin square design with four 21-d periods. cows were fed a total mixed ration containing 41.7% corn silage, 12.1% brewer's grains, and 46.2% concentrate on a dry matter basis. ...201727837973
crystal structure and pyridoxal 5-phosphate binding property of lysine decarboxylase from selenomonas ruminantium.lysine decarboxylase (ldc) is a crucial enzyme for acid stress resistance and is also utilized for the biosynthesis of cadaverine, a promising building block for bio-based polyamides. we determined the crystal structure of ldc from selenomonas ruminantium (srldc). srldc functions as a dimer and each monomer consists of two distinct domains; a plp-binding barrel domain and a sheet domain. we also determined the structure of srldc in complex with plp and cadaverine and elucidated the binding mode ...201627861532
synergism of cattle and bison inoculum on ruminal fermentation and select bacterial communities in an artificial rumen (rusitec) fed a barley straw based diet.this study evaluated the effect of increasing the proportion of bison relative to cattle inoculum on fermentation and microbial populations within an artificial rumen (rusitec). the experiment was a completely randomized design with a factorial treatment structure (proportion cattle:bison inoculum; 0:100, 33:67, 67:33, and 100:0) replicated in two rusitec apparatuses (n = 8 fermenters). the experiment was 15 d with 8 d of adaptation and 7 d of sampling. fermenters were fed a diet of 70:30 barley ...201628018336
lysine decarboxylase with an enhanced affinity for pyridoxal 5-phosphate by disulfide bond-mediated spatial reconstitution.lysine decarboxylase (ldc) catalyzes the decarboxylation of l-lysine to produce cadaverine, an important industrial platform chemical for bio-based polyamides. however, due to high flexibility at the pyridoxal 5-phosphate (plp) binding site, use of the enzyme for cadaverine production requires continuous supplement of large amounts of plp. in order to develop an ldc enzyme from selenomonas ruminantium (srldc) with an enhanced affinity for plp, we introduced an internal disulfide bond between ala ...201728095457
bacterial community diversity associated with different levels of dietary nutrition in the rumen of sheep.the sheep rumen microbial community plays an important role in animal performance and the environment. few studies have paid close attention to the impact of different levels of dietary nutrition on rumen microbial populations. a total of 112 healthy tan sheep were selected and randomly allotted to one of four dietary treatments (groups i, ii, iii, and iv). each treatment included four replicated pens with seven sheep each for a total of 28 sheep per treatment. the sheep were fed four diets with ...201728175950
effects of saccharomyces cerevisiae fermentation products on performance and rumen fermentation and microbiota in dairy cows fed a diet containing low quality forage.a possible option to meet the increased demand of forage for dairy industry is to use the agricultural by-products, such as corn stover. however, nutritional value of crop residues is low and we have been seeking technologies to improve the value. a feeding trial was performed to evaluate the effects of four levels of saccharomyces cerevisiae fermentation product (scfp; original xp; diamond v) on lactation performance and rumen fermentation in mid-lactation holstein dairy cows fed a diet contain ...201728465826
effect of sunflower and marine oils on ruminal microbiota, in vitro fermentation and digesta fatty acid profile.this study using the rumen simulation technique (rusitec) investigated the changes in the ruminal microbiota and anaerobic fermentation in response to the addition of different lipid supplements to a ruminant diet. a basal diet with no oil added was the control, and the treatment diets were supplemented with sunflower oil (2%) only, or sunflower oil (2%) in combination with fish oil (1%) or algae oil (1%). four fermentation units were used per treatment. rusitec fermenters were inoculated with r ...201728676798
effect of ginkgo extract supplementation on in vitro rumen fermentation and bacterial profiles under different dietary conditions.ginkgo extract was applied to a batch culture study and evaluated for its potential as a feed additive for ruminant animals under different forage-to-concentrate (f:c) ratios (1:9, 3:7, 5:5, 7:3 and 9:1). rumen fluid was mixed with respective diet and incubated at 39°c for 24 h with and without ginkgo extract (1.6% fruit equivalent in culture). methane production was significantly decreased by ginkgo extract, with the greatest reductions found in the 5:5 (41.9%) followed by the 7:3 ratios (36.7% ...201728707415
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