| chemotaxis-guided movements in bacteria. | motile bacteria often use sophisticated chemotaxis signaling systems to direct their movements. in general, bacterial chemotactic signal transduction pathways have three basic elements: (1) signal reception by bacterial chemoreceptors located on the membrane; (2) signal transduction to relay the signals from membrane receptors to the motor; and (3) signal adaptation to desensitize the initial signal input. the chemotaxis proteins involved in these signal transduction pathways have been identifie ... | 2004 | 15284186 |
| 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 ... | 2002 | 11922759 |
| enrichment and isolation of rumen bacteria that reduce trans- aconitic acid to tricarballylic acid. | bacteria from the bovine rumen capable of reducing trans-aconitate to tricarballylate were enriched in an anaerobic chemostat containing rumen fluid medium and aconitate. after 9 days at a dilution rate of 0.07 h, the medium was diluted and plated in an anaerobic glove box. three types of isolates were obtained from the plates (a crescent-shaped organism, a pleomorphic rod, and a spiral-shaped organism), and all three produced tricarballylate in batch cultures that contained glucose and trans-ac ... | 1985 | 16346691 |
| 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 ... | 1990 | 16348278 |
| 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 ... | 2002 | 12162576 |
| covalently linked polyamines in the cell wall peptidoglycan of selenomonas, anaeromusa, dendrosporobacter, acidaminococcus and anaerovibrio belonging to the sporomusa subbranch. | | 2002 | 12469301 |
| correlations between bacterial levels in autologous subgingival plaque and saliva of adult sudanese. | the aim of this study was to assess levels of oral bacteria and their correlations in paired samples of saliva and subgingival plaque in a population of adult sudanese. whole saliva and pooled subgingival plaque samples from six probing sites of one tooth in each jaw were obtained from 56 sudanese adults (mean age 35.2+/-8.9 years). levels of 24 oral bacteria in the autologous saliva and pooled plaque sample of each subject were assessed by dna probes and checkerboard dna-dna hybridization. ther ... | 2002 | 12483235 |
| desulfosporomusa polytropa gen. nov., sp. nov., a novel sulfate-reducing bacterium from sediments of an oligotrophic lake. | five strains of sulfate-reducing bacteria were isolated from the highest positive dilutions of a most probable number (mpn) series supplemented with lactate and inoculated with sediments from the oligotrophic lake stechlin. the isolates were endospore-forming and were motile by means of laterally inserted flagella. they stained gram-negative and contained b-type cytochromes. co difference spectra indicated the presence of p582 as a sulfite reductase. phylogenetic analyses of the 16s rdna sequenc ... | 2004 | 15340785 |
| 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 ... | 2000 | 12483585 |
| diet influences the ecology of lactic acid bacteria and escherichia coli along the digestive tract of cattle: neural networks and 16s rdna. | in this manuscript, the authors have sought to gain a better understanding of the interactions between escherichia coli and lactic acid bacteria (lab) isolated from rogossa mrs agar along the digestive tract of grain- and forage-fed cattle. e. coli from cattle receiving a high-grain diet were more numerous (p<0.05) than from the high-forage diet and the highest numbers were in the faeces. isolates on rogossa mrs agar were always greater in the high-grain diet (p<0.05) and contained a significant ... | 2003 | 12576580 |
| 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) ... | 2002 | 12583709 |
| periodontal microflora of hiv infected patients with periodontitis. | the aim of this study was to determine the microbial profile of periodontal lesions in hiv seropositive patients and to compare it with rapidly progressing periodontal lesions in systemically healthy patients. the subgingival microflora of 20 cdc ii, 20 cdc iii, 20 cdc iv/v and 20 systemically healthy patients with rapidly progressing periodontitis was examined. four sites with greatest probing depth in each patient were selected for microbiological sampling. the samples were cultured aerobicall ... | 1997 | 16887570 |
| subgingival microbiota levels and their associations with periodontal status at the sampled sites in an adult sudanese population using miswak or toothbrush regularly. | little information is available on the effect of miswak use on gingival microbiota. we assessed levels of 28 oral bacteria in subgingival plaque of adult sudanese miswak (n = 38) and toothbrush users (n = 36) age range 20-53 years (mean 34.6 years) to study associations between these bacteria, oral hygiene method, and periodontal status at the sampled sites. a pooled subgingival plaque sample from 6 probing sites of 1 selected tooth in each jaw was obtained from each subject. whole genomic dna p ... | 2003 | 12790510 |
| effects of a chlorhexidine gluconate-containing mouthwash on the vitality and antimicrobial susceptibility of in vitro oral bacterial ecosystems. | oral bacterial microcosms, established using saliva inocula from three individuals, were maintained under a feast-famine regime within constant-depth film fermenters. steady-state communities were exposed four times daily, postfeeding, to a chlorhexidine (chx) gluconate-containing mouthwash (chxm) diluted to 0.06% (wt/vol) antimicrobial content. the microcosms were characterized by heterotrophic plate counts and pcr-denaturing gradient gel electrophoresis (dgge). chxm caused significant decrease ... | 2003 | 12902270 |
| anaerobic bacteria cultured from the tongue dorsum of subjects with oral malodor. | the bacteria on the dorsum of the tongue are the most frequent cause of oral malodor; however, the bacterial flora of the tongue has not been well defined. although recent studies have used dna probes to detect the presence of certain periodontal pathogens, cultural studies have been limited because of the complexity of the flora of the tongue dorsum. the purpose of this study was to grow and to identify maximum numbers of capnophylic gram-negative bacilli and anaerobic micro-organisms by cultur ... | 2003 | 16887710 |
| selenomonas boskamp, 1922; a genus that includes species showing an unusual type of flagellation. | | 1954 | 13189856 |
| isolation, enumeration, and characteristics of proteolytic ruminal bacteria. | fulghum, robert s. (virginia polytechnic institute, blacksburg) and w. e. c. moore. isolation, enumeration, and characteristics of proteolytic ruminal bacteria. j. bacteriol. 85:808-815. 1963.-colony counts of proteolytic ruminal bacteria in the order of 10(9) organisms per g of whole rumen contents, and total colony counts in the order of 2 to 3 x 10(9) organisms per g, were obtained from rumen contents of cattle fed a maintenance ration of hay and grain. the proteolytic counts averaged 38% of ... | 1963 | 14044947 |
| effects of triclosan-containing rinse on the dynamics and antimicrobial susceptibility of in vitro plaque ecosystems. | dental plaque microcosms were established under a feast-famine regimen within constant-depth film fermentors and exposed four times daily postfeeding to a triclosan (tr)-containing rinse (dentifrice) (trd). this was diluted so that the antimicrobial content was 0.6 mg/ml. microcosms were characterized by heterotrophic plate counts and pcr-denaturing gradient gel electrophoresis (dgge) with primers specific for the v2-v3 region of the eubacterial 16s rrna gene (rdna). dominant isolates and pcr am ... | 2003 | 14576113 |
| structures of selenomonas ruminantium phytase in complex with persulfated phytate: dsp phytase fold and mechanism for sequential substrate hydrolysis. | various inositide phosphatases participate in the regulation of inositol polyphosphate signaling molecules. plant phytases are phosphatases that hydrolyze phytate to less-phosphorylated myo-inositol derivatives and phosphate. the phytase from selenomonas ruminantium shares no sequence homology with other microbial phytases. its crystal structure revealed a phytase fold of the dual-specificity phosphatase type. the active site is located near a conserved cysteine-containing (cys241) p loop. we al ... | 2004 | 15530366 |
| periodontal infections and pre-term low birth weight: a case-control study. | pre-term delivery of low-birth-weight infants [pre-term low birth weight (plbw)] remains a significant public health issue and a major cause of neonatal death and long-term health problems. there is a growing consensus that infections remote from fetal-placental unit may influence plbw infants. recent studies have suggested that maternal periodontal disease may be an independent risk factor for plbw. the purpose of the present study was to evaluate the possible link between periodontal infection ... | 2005 | 15691348 |
| molecular analysis of microbial diversity in advanced caries. | real-time pcr analysis of the total bacterial load in advanced carious lesions has shown that the total load exceeds the number of cultivable bacteria. this suggests that an unresolved complexity exists in bacteria associated with advanced caries. in this report, the profile of the microflora of carious dentine was explored by using dna extracted from 10 lesions selected on the basis of comparable total microbial load and on the relative abundance of prevotella spp. using universal primers for t ... | 2005 | 15695690 |
| underrepresentation of short palindromes in selenomonas ruminantium dna: evidence for horizontal gene transfer of restriction and modification systems? | molecular analysis of isolates of the rumen bacterium selenomonas ruminantium revealed a high variety and frequency of site-specific (restriction) endonucleases. while all known s. ruminantium restriction and modification systems recognize hexanucleotide sequences only, consistently low counts of both 6-bp and 4-bp palindromes were found in dna sequences of s. ruminantium. statistical analysis indicated that there is some correlation between the degree of underrepresentation of tetranucleotide w ... | 2005 | 15980893 |
| 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 ... | 2007 | 17235560 |
| bacterial diversity in necrotizing ulcerative periodontitis in hiv-positive subjects. | necrotizing ulcerative periodontitis (nup) is a painful and potentially debilitating affliction that affects about 2% to 6% of hiv-positive subjects. nup may be caused by specific microorganisms that are presently unknown or by microbial species not usually thought to cause periodontal infections. the purpose of this study was to define the bacterial species associated with nup in hiv-positive patients. | 2002 | 16013212 |
| identification of candidate periodontal pathogens and beneficial species by quantitative 16s clonal analysis. | most studies of the bacterial etiology of periodontitis have used either culture-based or targeted dna approaches, and so it is likely that pathogens remain undiscovered. the purpose of this study was to use culture-independent, quantitative analysis of biofilms associated with chronic periodontitis and periodontal health to identify pathogens and beneficial species. samples from subjects with periodontitis and controls were analyzed using ribosomal 16s cloning and sequencing. several genera, ma ... | 2005 | 16081935 |
| interaction of gut microflora with tannins in feeds. | tannins (hydrolyzable and condensed) are water-soluble polyphenolic compounds that exert antinutritional effects on ruminants by forming complexes with dietary proteins. they limit nitrogen supply to animals, besides inhibiting the growth and activity of ruminal microflora. however, some gastrointestinal microbes are able to break tannin-protein complexes while preferentially degrading hydrolyzable tannins (hts). streptococcus gallolyticus, lonepinella koalarum and selenomonas ruminantium are th ... | 2005 | 16193308 |
| comparison of substrate affinities among several rumen bacteria: a possible determinant of rumen bacterial competition. | five rumen bacteria, selenomonas ruminantium, bacteroides ruminicola, megasphaera elsdenii, streptococcus bovis, and butyrivibrio fibrisolvens were grown in continuous culture. estimates of substrate affinities were derived from lineweaver-burk plots of dilution rate versus substrate concentration. each bacterium was grown on at least four of the six substrates: glucose, maltose, sucrose, cellobiose, xylose, and lactate. wide variations in substrate affinities were seen among the substrates util ... | 1979 | 16345358 |
| 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 ... | 2008 | 17965150 |
| 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. | 2008 | 18217928 |
| comparison of maintenance energy expenditures and growth yields among several rumen bacteria grown on continuous culture. | maintenance energy expenditures were mesured for five rumen bacteria, selenomonas ruminantium, butyrivibrio fibrisolvens, bacteroides ruminicola, megasphaera elsdenii, and streptococcus bovis, by using a complex medium with glucose as the carbon source. large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. the suggestion is made that maintenance requirements could be a significant determinant of bacterial competition in the rumen. theoretical ... | 1979 | 16345359 |
| changes in lactate-producing and lactate-utilizing bacteria in relation to ph in the rumen of sheep during stepwise adaptation to a high-concentrate diet. | changes in the numbers and types of lactate-producing and lactate-utilizing bacteria in the rumen of sheep were followed during stepwise adaptation from a low- to a high-concentrate diet. the mean numbers of bacteria increased after each change in diet when increasing amounts of maize grain were substituted for maize stover. a surge in number of amylolytic bacteria always preceded an increase in lactate-utilizing bacteria, and with the final diet containing 71% grain and molasses the two groups ... | 1979 | 16345431 |
| effects of long-chain fatty acids on growth of rumen bacteria. | the effects of low concentrations of long-chain fatty acids (palmitic, stearic, oleic, and vaccenic) on the growth of seven species (13 strains) of rumen bacteria were investigated. except for bacteroides ruminicola and several strains of butyrivibrio fibrisolvens, bacterial growth was not greatly affected by either palmitic or stearic acids. in contrast, growth of selenomonas ruminantium, b. ruminicola, and one strain of b. fibrisolvens was stimulated by oleic acid, whereas the cellulolytic spe ... | 1981 | 16345887 |
| changes in viability, cell composition, and enzyme levels during starvation of continuously cultured (ammonia-limited) selenomonas ruminantium. | under nitrogen (ammonia)-limited continuous culture conditions, the ruminal anaerobe selenomonas ruminantium was grown at various dilution rates (d). the proportion of the population that was viable increased with d, being 91% at d = 0.5 h. washed cell suspensions were subjected to long-term nutrient starvation at 39 degrees c. all populations exhibited logarithmic linear declines in viability that were related to the growth rate. cells grown at d = 0.05, 0.20, and 0.50 lost about 50% viability ... | 1982 | 16346116 |
| 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 ... | 1990 | 16348287 |
| 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 ... | 1990 | 16348354 |
| 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 ... | 2006 | 16354653 |
| 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 ... | 2008 | 18421594 |
| a new checkerboard panel for testing bacterial markers in periodontal disease. | various microbiological methods have been used for testing bacterial markers for periodontitis and periodontal disease progression. most studies have used only a limited number of well recognized bacterial species. the purpose of the present study was to evaluate the association of 13 more recently identified bacterial species in a new panel in comparison with 12 previously more recognized periodontotopathogens ('old panel') using the 'checkerboard' dna-dna hybridization method. | 2006 | 16390335 |
| novel subgingival bacterial phylotypes detected using multiple universal polymerase chain reaction primer sets. | molecular ecological analysis based on 16s rrna gene sequence analysis is well established for the characterisation of complex bacterial communities. however, 'universal' pcr primers can introduce biases into the analysis of the species composition of clone libraries because of mismatches between the primer and target organism sequences. in this study, three universal primer sets were compared for the analysis of the microflora in subgingival plaque. | 2006 | 16390343 |
| composition of the bacterial flora in tonsilloliths. | tonsilloliths are a potential cause of oral malodor. in this study, microbial profiles and composition of tonsilloliths were determined using culture-independent molecular methods and scanning electron microscopy. 16s ribosomal rna bacterial genes (16s rdnas) isolated from tonsilloliths of 6 individuals were amplified by pcr and cloned into escherichia coli. partial 16s rdna sequences of approximately 600 bases of cloned inserts were used to determine species identity by comparison with sequence ... | 2006 | 16859950 |
| subgingival microflora in smokers with early onset periodontitis. | cigarette smoking is a potent risk factor which has recently been associated with periodontal disease progression. the objective of this study was to detect the microbial profile of early onset periodontitis in smokers and compare it to that of non-smokers. the study population consisted of 50 systemically healthy individuals aged 25 to 38 years, exhibiting early onset periodontitis. 25 patients were smokers (> 20 cigarettes/day) and 25 non-smokers. two pooled bacterial samples comprised of four ... | 1997 | 16887581 |
| clinical and microbiological profiles of human immunodeficiency virus (hiv)-seropositive brazilians undergoing highly active antiretroviral therapy and hiv-seronegative brazilians with chronic periodontitis. | this study compares the periodontal clinical profile and the composition of the subgingival microbiota of human immunodeficiency virus (hiv)-seropositive and hiv-seronegative subjects with chronic periodontitis. | 2007 | 17199544 |
| geobacter pickeringii sp. nov., geobacter argillaceus sp. nov. and pelosinus fermentans gen. nov., sp. nov., isolated from subsurface kaolin lenses. | the goal of this project was to isolate representative fe(iii)-reducing bacteria from kaolin clays that may influence iron mineralogy in kaolin. two novel dissimilatory fe(iii)-reducing bacteria, strains g12(t) and g13(t), were isolated from sedimentary kaolin strata in georgia (usa). cells of strains g12(t) and g13(t) were motile, non-spore-forming regular rods, 1-2 mum long and 0.6 mum in diameter. cells had one lateral flagellum. phylogenetic analyses using the 16s rrna gene sequence of the n ... | 2007 | 17220454 |
| 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, ... | 2008 | 18676492 |
| profiling of bacterial flora in crevices around titanium orthodontic anchor plates. | the aims of this study were to characterize the microflora in crevices around titanium orthodontic anchor plates using anaerobic culture and molecular biological techniques for bacterial identification, and to compare the microbial composition between crevices around anchor plates and gingival crevices. | 2007 | 17224019 |
| 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 ... | 2007 | 17567745 |
| 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 ... | 2008 | 18837167 |
| 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 ... | 2007 | 17588525 |
| 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 ... | 2007 | 17625266 |
| 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 ... | 2007 | 17689155 |
| 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 ... | 2008 | 18256468 |
| microbiological diversity of generalized aggressive periodontitis by 16s rrna clonal analysis. | the purpose of this study was to determine the bacterial diversity in the subgingival plaque of subjects with generalized aggressive periodontitis by using culture-independent molecular methods based on 16s ribosomal dna cloning. | 2008 | 18279178 |
| 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 ... | 2009 | 19194751 |
| does pregnancy have an impact on the subgingival microbiota? | we investigated clinical and subgingival microbiologic changes during pregnancy in 20 consecutive pregnant women > or =18 years not receiving dental care. | 2009 | 19228092 |
| identification of microbial biofilms in osteonecrosis of the jaws secondary to bisphosphonate therapy. | biofilm theory has emerged to explain the etiology of the chronic infections that have come to constitute between 65% to 80% of the microbial diseases treated by physicians in the developed world. the purpose of this article is to report for the first time the observation of multispecies microbial biofilms on affected bone in patients with osteonecrosis of the jaws (onj) secondary to bisphosphonate therapy. | 2008 | 18355603 |
| 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 ... | 2008 | 18358762 |
| 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 ... | 2008 | 18374656 |
| 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 ... | 2010 | 19662514 |
| microbiologic and immunologic characteristics of periodontal disease in hispanic americans with type 2 diabetes. | the microbiology of periodontitis in type 1 diabetes has been reported, but less is known about type 2 diabetes. moreover, these data have not linked microbial colonization, host response, and clinical presentation in type 1 or type 2 diabetes. the objectives of this study were to relate periodontal status, periodontal microorganisms, and host-response characteristics in hispanic americans with type 2 diabetes. | 2008 | 18380556 |
| assessment of intraradicular bacterial composition by terminal restriction fragment length polymorphism analysis. | the aim of the study was to assess the bacterial community structures associated with endodontic infections using terminal restriction fragment length polymorphism (t-rflp), and to investigate the correlation of whole community profiles with the manifestation of particular clinical features. | 2009 | 19702949 |
| bacterial profiles of root caries in elderly patients. | culture-based studies have shown that streptococcus mutans and lactobacilli are associated with root caries (rc). the purpose of the present study was to assess the bacterial diversity of rc in elderly patients by use of culture-independent molecular techniques and to determine the associations of specific bacterial species or bacterial communities with healthy and carious roots. plaque was collected from root surfaces of 10 control subjects with no rc and from 11 subjects with rc. the bacterial ... | 2008 | 18385433 |
| 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 ... | 2010 | 19757178 |
| diverse and novel oral bacterial species in blood following dental procedures. | we identified oral bacterial species in blood cultures following single-tooth extraction and tooth brushing. sequence analysis of 16s rrna genes identified 98 different bacterial species recovered from 151 bacteremic subjects. of interest, 48 of the isolates represented 19 novel species of prevotella, fusobacterium, streptococcus, actinomyces, capnocytophaga, selenomonas, and veillonella. | 2008 | 18434561 |
| 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 ... | 1995 | 16887543 |
| 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 ... | 1999 | 16887660 |
| rna:protein ratio of the unicellular organism as a characteristic of phosphorous and nitrogen stoichiometry and of the cellular requirement of ribosomes for protein synthesis. | mean phosphorous:nitrogen (p:n) ratios and relationships of p:n ratios with the growth rate of organisms indicate a surprising similarity among and within microbial species, plants, and insect herbivores. to reveal the cellular mechanisms underling this similarity, the macromolecular composition of seven microorganisms and the effect of specific growth rate (sgr) on rna:protein ratio, the number of ribosomes, and peptide elongation rate (per) were analyzed under different conditions of exponenti ... | 2006 | 16953894 |
| 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 ... | 2010 | 20352422 |
| 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 ... | 2006 | 17007426 |
| diversity of phytases in the rumen. | examples of a new class of phytase related to protein tyrosine phosphatases (ptp) were recently isolated from several anaerobic bacteria from the rumen of cattle. in this study, the diversity of ptp-like phytase gene sequences in the rumen was surveyed by using the polymerase chain reaction (pcr). two sets of degenerate primers were used to amplify sequences from rumen fluid total community dna and genomic dna from nine bacterial isolates. four novel ptp-like phytase sequences were retrieved fro ... | 2007 | 17186149 |
| 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. | 2010 | 20456526 |
| screening of bacteria from the cattle gastrointestinal tract for inhibitory activity against enterohemorrhagic escherichia coli o157:h7, o111:h-, and o26:h11. | a quick and reproducible microgel plate assay was adapted to screen bacteria from cattle gastrointestinal tracts for production of compounds inhibitory to the growth of three enterohemorrhagic escherichia coli (ehec) serotypes: o157:h7, o111:h-, and o26:h11. the inhibitory activity of 309 bacteria, isolated on several agar media, was assessed by a microgel assay performed in 96-well microtiter plates. fifty-three isolates secreted inhibitory compounds with a molecular weight of less than 1,000. ... | 2006 | 17186648 |
| psychrosinus fermentans gen. nov., sp. nov., a lactate-fermenting bacterium from near-freezing oxycline waters of a meromictic antarctic lake. | a novel, obligately anaerobic, fermentative bacterium, strain fcf9, was isolated from a 9-m water sample from permanently ice-covered, meromictic lake fryxell, antarctica. a phylogenetic analysis based on 16s rrna gene sequence identity clustered the antarctic isolate within the sporomusa-pectinatus-selenomonas phyletic group, where it was most closely related to pelosinus fermentans (95.5% sequence identity). however, unlike species of pelosinus, strain fcf9 was psychrophilic, with growth occur ... | 2008 | 18673392 |
| terminal restriction fragment length polymorphism analysis of the microflora in necrotic teeth of patients irradiated in the head and neck region. | this study evaluated the microflora in root canals of necrotic teeth after radiotherapy of the head and neck region. the microbial composition of samples taken from necrotic root canals in patients treated with irradiation of the head and neck (group a, n = 13) and in healthy controls (group b, n = 11) was analyzed by terminal restriction fragment-length polymorphism (t-rflp) analysis. a total of 50 different terminal restriction fragment lengths (t-rfs) (each representing one or more bacterial ... | 2008 | 18718363 |
| kinetics, substrate specificity, and stereospecificity of two new protein tyrosine phosphatase-like inositol polyphosphatases from selenomonas lacticifex. | inositol polyphosphatases (ippases) play an important role in the metabolism of inositol polyphosphates, a class of molecules involved in signal transduction. here we characterize 2 new protein tyrosine phosphatase-like ippases (phyasl and phybsl) cloned from selenomonas lacticifex that can hydrolyze myo-inositol hexakisphosphate (insp6) in vitro. to determine their preferred substrates and stereospecificity of insp6 dephosphorylation, a combination of kinetic and high-performance ion pair chrom ... | 2008 | 18756327 |
| 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 ... | 2009 | 18839246 |
| 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 ... | 2010 | 20851965 |
| 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 ... | 2010 | 20880288 |
| specified species in gingival crevicular fluid predict bacterial diversity. | analysis of gingival crevicular fluid (gcf) samples may give information of unattached (planktonic) subgingival bacteria. our study represents the first one targeting the identity of bacteria in gcf. | 2010 | 21049043 |
| 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 ... | 2009 | 18953511 |
| 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 ... | 2009 | 18973836 |
| the microbiota of acute apical abscesses. | as the breadth of bacterial diversity in the oral cavity has been deciphered by molecular studies, several newly identified species/phylotypes have emerged as potential pathogens. we hypothesized that many of these species/phylotypes could also be involved with the etiology of endodontic abscesses. abscess aspirates from 42 persons were analyzed for the presence of 81 species/phylotypes by means of a reverse-capture checkerboard hybridization assay. associations between the most frequently detec ... | 2009 | 19131319 |
| 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 ... | 2011 | 21398553 |
| 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 ... | 2009 | 19194750 |
| [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. | 2008 | 19271530 |
| 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 ... | 2011 | 21538241 |
| 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 ... | 2011 | 21822435 |
| is obesity an oral bacterial disease? | the world-wide explosion of overweight people has been called an epidemic. the inflammatory nature of obesity is widely recognized. could it really be an epidemic involving an infectious agent? in this climate of concern over the increasing prevalence of overweight conditions in our society, we focus on the possible role of oral bacteria as a potential direct contributor to obesity. to investigate this possibility, we measured salivary bacterial populations of overweight women. saliva was collec ... | 2009 | 19587155 |
| 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 ... | 2007 | 18478379 |
| group-specific pcr-rflp and real-time pcr methods for detection and tentative discrimination of strictly anaerobic beer-spoilage bacteria of the class clostridia. | the strictly anaerobic brewery contaminants of the genera pectinatus, megasphaera, selenomonas and zymophilus in the class clostridia constitute an important group of spoilage bacteria of unpasteurised, packaged beers. the aim of this study was to develop and evaluate group-specific pcr methods to detect and differentiate these bacteria in beer. a group-specific primer pair targeting a 342-bp variable region of the 16s rrna gene was designed and evaluated in end-point pcr with gel electrophoresi ... | 2008 | 18502530 |
| 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 ... | 2008 | 18573100 |
| microorganisms in root canal-treated teeth from a german population. | posttreatment apical periodontitis is usually associated with persistent or secondary intraradicular infection. this study evaluated the presence and relative levels of 28 bacterial taxa in treated root canals of teeth with posttreatment apical periodontitis from german patients using 16s ribosomal rna (rrna) gene probes in a reverse-capture checkerboard hybridization assay. species-specific polymerase chain reaction (pcr) was also performed to detect enterococcus faecalis and candida albicans. ... | 2008 | 18634922 |
| selenomonas bovis sp. nov., isolated from yak rumen contents. | two strictly anaerobic, crescent-shaped bacterial strains, designated wgt and ycb08, were isolated from a cellulose-degrading mixed culture enriched from yak rumen contents. the strains were gram-negative, non-spore-forming and motile, with four to six flagella situated at the centre of the concave side of the cell. the cells were 0.9-1.1x4-6 microm. growth was observed at 27-46 degrees c (optimum 39 degrees c) and ph 4.2-8.3 (optimum ph 7.0-7.2). arabinose, glucose, mannose, cellobiose, lactose ... | 2009 | 19605710 |
| 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. | 2010 | 19702858 |
| comparisons of subgingival microbial profiles of refractory periodontitis, severe periodontitis, and periodontal health using the human oral microbe identification microarray. | this study compared the subgingival microbiota of subjects with refractory periodontitis (rp) to those in subjects with treatable periodontitis (grs = good responders) or periodontal health (ph) using the human oral microbe identification microarray (homim). | 2009 | 19722792 |
| oral microbiota of children in a school-based dental clinic. | dental caries disproportionately affects disadvantaged subjects. this study hypothesized that there were greater caries extent and higher levels of caries-associated and anaerobic subgingival bacterial species in oral samples of hispanic and immigrant children compared with non-hispanic and us born children. | 2010 | 19879369 |
| 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 ... | 2010 | 19921178 |
| 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 ... | 2010 | 20127424 |
| effects of ultrasonic, electric, and manual toothbrushes on subgingival plaque composition in orthodontically banded molars. | orthodontic appliances hinder mechanical plaque control. in this study, we evaluated the effect of self-performed supragingival plaque removal with ultrasonic, electric, and manual toothbrushes on subgingival plaque composition in orthodontically banded molars. | 2010 | 20152680 |
| selenomonas may puzzle the diagnosis of helicobacter pylori in gastric mucosa. | | 2010 | 20401507 |
| 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 ... | 2010 | 20450933 |