fluorescent-antibody study of natural finger-like zoogloeae.fluorescent-antibody techniques using zoogloea ramigera 106 antiserum were used to study fresh activated sludge flocs and finger-like zoogloeae in the microbial film that developed over stored samples of activated sludge. few cells in fresh activated sludge reacted positively with the fluorescein-labeled antiserum. finger-like zoogloeae containing reactive cells were readily observed in the microbial film layer over stored activated sludge. certain of the naturel finger-like projections were ent ...19751096822
an enzymatic assay method for d(-)-3-hydroxybutyrate and acetoacetate involving acetoacetyl coenzyme a synthetase from zoogloea enzyme assay method for d(-)-3-hydroxybutyrate and acetoacetate involving acetoacetyl coenzyme a (coa) synthetase was developed. to determine the concentration of d-3-hydroxybutyrate, it was oxidized with d-3-hydroxybutyrate dehydrogenase in the presence of nicotinamide adenine dinucleotide (nad+) to acetoacetate, which was then converted to acetyl coa via acetoacetyl coa through the combined actions of acetoacetyl coa synthetase and 3-ketothiolase in the presence of adenosine triphosphate (a ...19902208372
fine structural analysis of the zoogloea ramigera phba-phbb locus encoding beta-ketothiolase and acetoacetyl-coa reductase: nucleotide sequence of phbb.a series of expression plasmids containing either the complete insert from plasmid pucdbk1 (peoples et al., 1987) or sub-fragments thereof were constructed in a tac promoter vector. analysis of protein lysates of induced cultures of these clones identified the gene encoding nadph-specific acetoacetyl-coa reductase in the 2.3kb of sequence located downstream from the beta-ketothiolase gene in plasmid pucdbk1. the complete nucleotide sequence (2.1kb) of this region was determined. an open reading ...19892546004
purification and characterization of nadp-linked acetoacetyl-coa reductase from zoogloea ramigera nadp-linked acetoacetyl-coa reductase was purified to electrophoretic homogeneity from zoogloea ramigera i-16-m, a poly(3-hydroxybutyrate)-accumulating bacterium. the purified enzyme showed specific activity of 412 mumol acetoacetyl-coa reduced per min per mg protein, which constituted an 880-fold purification compared to the crude extract, with a 32% yield. electrophoretic analysis of the purified enzyme which had been cross-linked with dimethylsuberimidate showed that the native enzyme (mr ...19873542050
improved staining of extracellular polymer for electron microscopy: examination of azotobacter, zoogloea, leuconostoc, and bacillus.phase contrast, ultraviolet microscopy, and freeze-etching were used to determine the amount of exocellular polymer surrounding unfixed cells of four genera of bacteria: azotobacter vinelandii, zoogloea ramigera, leuconostoc mesenteroides, and an acid-tolerant, floc-forming bacillus species. thin-sectional electron microscopy was employed to measure the effectiveness of a modified ruthenium red staining method. the results obtained with this modification of ruthenium red staining technique were ...19724116892
critical-point drying: rapid method for the determination of bacterial extracellular polymer and surface structures.the relative amount of extracellular polymer which remains about azotobacter vinelandii, zoogloea ramigera, klebsiella pneumoniae, and diplococcus pneumoniae after critical-point drying was studied by electron microscopy. the results obtained with this technique are compared to those obtained with methods that illustrate extracellular polymer, such as freeze-etching and ruthenium red staining. comparative results indicate critical-point drying to be a rapid, reliable method for the determination ...19744136617
volutin granules in zoogloea ramigera.zoogloea ramigera, a gram-negative bacterium found in activated sludge, formed volutin granules when excess orthophosphate was added to a phosphate-starved culture. these volutin granules were stainable by hydrogen sulfide after lead acetate treatment and extractable by n-perchloric acid but were not adsorbed by activated charcoal. they appeared to consist of inorganic polyphosphate. optimum granule formation in the arginine broth required 10 g of glucose, 3 mg of phosphate, and 1 to 20 mg of ma ...19704195479
fine structure and composition of the zoogloeal matrix surrounding zoogloea ramigera.the fingerlike projections, which have been considered to be characteristic of the genus zoogloea, appear to consist of generally globular packets of cells, each surrounded by capsular matrix. the individual packets which surround z. ramigera 115 cells appear to adhere one to another by intermeshed fibrils that measure 2 to 5 nm in diameter. the fibril polymer appears to be polyglucose that is susceptible to cellulase. the polymer resembles cellulose in several respects, with the exception that ...19684881706
ester synthesis by zoogloea ramigera 115 grown in the presence of ethanol.the ester ethyl butyrate is produced by zoogloea ramigera 115, a bacterium isolated from an aerobic waste treatment plant, when ethanol is present in culture media. the cells appear to produce butyric acid which is then esterified with residual ethanol in the culture medium.19725021972
influence of ph and metal cations on aggregative growth of non-slime-forming strains of zoogloea ramigera.aggregative growth of non-slime-forming strains of zoogloea ramigera was induced by growing the organisms at a depressed ph. calcium and magnesium ion was found to reverse aggregative growth of the organisms. conversely, aggregation was stimulated when the available inorganic cation concentration of the growth medium was lowered by the use of a chelating agent. the aggregative effects of ph depression or cation depletion and the dispersal effects of cation supplementation were observed only duri ...19694976326
inhibition of acetoacetyl-coa synthetase from rat liver by fatty acyl-coas.the activity of acetoacetyl-coa synthetase from rat liver was found to be negatively regulated by coenzyme a, fatty acyl-coas and acetoacetyl-coa in vitro. with increasing concentrations of coenzyme a (substrate inhibition occurring at concentrations higher than 50 microm) the ph optimum shifted toward the acidic side (7.5-8.5 with 5 microm coenzyme a and 6.5-7.0 with 500 microm coenzyme a), in parallel with progressively decreasing enzyme activity. fatty acyl-coas of various chain lengths dose- ...19873689812
the nadph-linked acetoacetyl-coa reductase from zoogloea ramigera. characterization and mechanistic studies of the cloned enzyme over-produced in escherichia coli.the nadph-linked acetoacetyl-coa reductase, (r)-3-hydroxyacyl-coa dehydrogenase (ec, from the bacterium zoogloea ramigera, involved in the formation of d-3-hydroxybutyryl-coa for poly(d-3-hydroxybutyrate) biosynthesis, has been purified from an over-producing escherichia coli strain. the purification was achieved in two steps, yielding an electrophoretically homogeneous enzyme of high specific activity (608 u/mg). the enzyme is an alpha 4 homotetramer of four 25-kda subunits. it has a ...19883286259
purification and properties of d(-)-3-hydroxybutyrate-dimer hydrolase from zoogloea ramigera i-16-m.d(-)-3-hydroxybutyrate-dimer hydrolase from zoogloea ramigera i-16-m was purified 7000-fold to electrophoretic homogeneity. the molecular weight of the purified enzyme was 28 000 as determined by sephadex g-100 gel filtration, and 30 000 as estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. the isoelectric point was at ph 5.7. the ph optimum for the enzyme reaction was 8.0. the dimer hydrolase was stereospecific for d(-)-3-[d(-)-3-hydroxybutyryloxy]butyric ...19817285912
oxygen and nitrate reduction kinetics of a nonflocculating strain of zoogloea ramigera.the oxygen and nitrate reduction kinetics of a nonflocculating strain of zoogloea ramigera were determined. axenic, nitrate-reducing bacterial suspensions were acclimated to various oxygen levels in a chemostat while measuring nitrate reduction in the presence of high ammonium nitrogen concentrations. significant nitrate reduction was observed at oxygen concentrations up to 8 mg l-1. oxygen consumption was inhibited by oxygen concentrations in excess of 2 mg l-1.19883048205
biosynthetic thiolase from zoogloea ramigera. iii. isolation and characterization of the structural gene.the gene coding for the biosynthetic thiolase from zoogloea ramigera has been isolated by using antibody screening methods to detect its expression in escherichia coli under the transcriptional control of the lac promoter. we have located and determined the nucleotide sequence of the gene. the structural gene is 1173 nucleotides long and codes for a polypeptide of 391 amino acids; 282 nucleotides 5' and 58 nucleotides 3' to the coding sequence are also reported. by comparing the amino acid seque ...19872878929
characterization of an acetyl-coa c-acetyltransferase (thiolase) gene from clostridium acetobutylicum atcc 824.thiolase (thl) is an important enzyme at the junction in the pathway leading to the production of either acids (acetate or butyrate) or solvents (acetone, butanol or ethanol) during the growth of clostridium acetobutylicum atcc 824. cloning and expression of the thl-encoding gene (thl) has been described [petersen and bennett, appl. environ. microbiol. 57 (1991) 2735-2741], as has the purification and properties of the enzyme [wiesenborn et al., appl. environ. microbiol. 54 (1988) 2717-2722]. he ...19957867955
biosynthetic thiolase from zoogloea ramigera. ii. inactivation with haloacetyl coa analogs.the thiolase involved in biosynthesis of poly-beta-hydroxybutyrate in zoogloea ramigera generates an acetyl-enzyme species during catalysis. up to 0.86 [14c] acetyl eq/subunit of this homotetrameric enzyme is accumulated by acid precipitation in the presence of [14c]acetyl-coa. gel filtration of the same solutions produced only 7% acetyl-enzyme suggesting hydrolytic lability of the acetyl-enzyme during the 10-min isolation at 4 degrees c. in an effort to identify active site residues which may f ...19872878928
biosynthetic thiolase from zoogloea ramigera. i. preliminary characterization and analysis of proton transfer reaction.the biosynthetic thiolase, from zoogloea ramigera, involved in generation of acetoacetyl-coa for poly-beta-hydroxybutyrate synthesis, has been prepared pure in quantity for initial structural characterization of this homotetrameric enzyme. edman degradation provided the sequence of the nh2 terminal 25 residues and an active site cysteine-containing nonapeptide labeled on stoichiometric inactivation by iodoacetamide. both sequences were used to align the encoding dna sequence of the cloned gene a ...19872878927
proposal to reclassify zoogloea ramigera iam 12670 (p. r. dugan 115) as duganella zoogloeoides gen. nov., sp. nov.the taxonomic position of a misclassified strain, zoogloea remigera iam 12670t (= atcc 25925t = p. r. dugan 115t), was reevaluated. a phylogenetic analysis based on 16s ribosomal rdna sequences revealed that this organism was located in the beta subclass of the class proteobacteria with members of the genus telluria as its closest relatives. on the basis of phenotypic and phylogenetic information, we propose that this organism should be reclassified in a new taxon with the name duganella zoogloe ...19979336937
bacterial community dynamics during start-up of a trickle-bed bioreactor degrading aromatic compounds.this study was performed with a laboratory-scale fixed-bed bioreactor degrading a mixture of aromatic compounds (solvesso100). the starter culture for the bioreactor was prepared in a fermentor with a wastewater sample of a care painting facility as the inoculum and solvesso100 as the sole carbon source. the bacterial community dynamics in the fermentor and the bioreactor were examined by a conventional isolation procedure and in situ hybridization with fluorescently labeled rrna-targeted oligon ...19989501433
isolation of zoogloea ramigera i-16-m exopolysaccharide biosynthetic genes and evidence for instability within this region.the genetics of the biosynthesis of an exocellular polysaccharide (eps) from zoogloea ramigera i-16-m is being investigated. tn5 insertion mutants deficient in eps production were isolated by screening for the absence of fluorescence on plates containing the dye cellufluor (polysciences chemicals). complementation of these mutations was achieved with a z. ramigera i-16-m gene library constructed in a broad-host-range cosmid vector and introduced into the i-16-m mutants by conjugation. four recom ...19872820929
mechanistic studies on beta-ketoacyl thiolase from zoogloea ramigera: identification of the active-site nucleophile as cys89, its mutation to ser89, and kinetic and thermodynamic characterization of wild-type and mutant enzymes.thiolase proceeds via covalent catalysis involving an acetyl-s-enzyme. the active-site thiol nucleophile is identified as cys89 by acetylation with [14c]acetyl-coa, rapid denaturation, tryptic digestion, and sequencing of the labeled peptide. the native acetyl enzyme is labile to hydrolytic decomposition with t 1/2 of 2 min at ph 7, 25 degrees c. cys89 has been converted to the alternate nucleophile ser89 by mutagenesis and the c89s enzyme overproduced, purified, and assessed for activity. the s ...19892775734
ecophysiological and phylogenetic studies of nevskia ramosa in pure culture.during the last 100 years, the neuston bacterium nevskia ramosa has been described several times. this bacterium forms conspicuous rosette-like microcolonies at the air-water interface. in this study, pure cultures of nevskia ramosa were obtained for the first time, from a bog lake (strain soe1, dsmz 11499t) and a freshwater ditch (strain ol1, dsmz 11500). the isolates showed special adaptations to life in the epineuston. they formed hydrophobic surface films with a dull appearance. n. ramosa is ...19989572968
phylogeny of dissimilatory sulfite reductases supports an early origin of sulfate respiration.microorganisms that use sulfate as a terminal electron acceptor for anaerobic respiration play a central role in the global sulfur cycle. here, we report the results of comparative sequence analysis of dissimilatory sulfite reductase (dsr) genes from closely and distantly related sulfate-reducing organisms to infer the evolutionary history of dsr. a 1.9-kb dna region encoding most of the alpha and beta subunits of dsr could be recovered only from organisms capable of dissimilatory sulfate reduct ...19989603890
acetoacetyl coenzyme a reductase and polyhydroxybutyrate synthesis in rhizobium (cicer) sp. strain cc 1192biochemical controls that regulate the biosynthesis of poly-3-hydroxybutyrate (phb) were investigated in rhizobium (cicer) sp. strain cc 1192. this species is of interest for studying phb synthesis because the polymer accumulates to a large extent in free-living cells but not in bacteroids during nitrogen-fixing symbiosis with chickpea (cicer arietinum l.) plants. evidence is presented that indicates that cc 1192 cells retain the enzymic capacity to synthesize phb when they differentiate from th ...19989687441
specific ribosomal dna sequences from diverse environmental settings correlate with experimental contaminants.phylogenetic analysis of 16s ribosomal dna (rdna) clones obtained by pcr from uncultured bacteria inhabiting a wide range of environments has increased our knowledge of bacterial diversity. one possible problem in the assessment of bacterial diversity based on sequence information is that pcr is exquisitely sensitive to contaminating 16s rdna. this raises the possibility that some putative environmental rrna sequences in fact correspond to contaminant sequences. to document potential contaminant ...19989687486
estimating the growth rate of a bacterial species in a complex mixture by hybridization of genomic dna> abstract advances in molecular techniques have enabled new approaches to identifying bacteria. however, once identified, there is no quantitative information on the in situ growth rate of the species, mainly because the technology has not been available. the quantitative incorporation of [methyl-3h]thymidine into dividing bacteria is coupled with a molecular (hybridization) method, to determine the growth rate of bacterial species in situ. the basis of this molecular method is a reverse gene p ...19989688773
poly-beta-hydroxybutyrate biosynthesis in alcaligenes eutrophus h16. characterization of the genes encoding beta-ketothiolase and acetoacetyl-coa reductase.the poly-beta-hydroxybutyrate biosynthetic thiolase gene from zoogloea ramigera was used as a hybridization probe to screen restriction digests of alcaligenes eutrophus h16 dna. specific hybridization signals were obtained and two fragments (a 2.3-kilobase psti fragment and a 15-kilobase ecori fragment) cloned in the escherichia coli vector puc8 (plasmids paet3/paet10 and paet29, respectively). biochemical analysis of lysates of e. coli cells containing each plasmid identified significant levels ...19892670935
massilia timonae gen. nov., sp. nov., isolated from blood of an immunocompromised patient with cerebellar lesions.a fastidious, slowly growing, strictly aerobic, gram-negative bacterium was isolated from a culture of blood from a 25-year-old man with common variable immunodeficiency. the man had been admitted to hospital with febrile progressive cerebellar ataxia. the use of standard phenotypic schemes did not lead to identification, but sequence analysis demonstrated that the 16s rrna gene of the isolate was most similar to those of the environmental bacteria duganella zoogloeoides (formerly zoogloea ramig ...19989738031
molecular diversity of rhizobia occurring on native shrubby legumes in southeastern australiathe structure of rhizobial communities nodulating native shrubby legumes in open eucalypt forest of southeastern australia was investigated by a molecular approach. twenty-one genomic species were characterized by small-subunit ribosomal dna pcr-restriction fragment length polymorphism and phylogenetic analyses, among 745 rhizobial strains isolated from nodules sampled on 32 different legume host species at 12 sites. among these rhizobial genomic species, 16 belonged to the bradyrhizobium subgro ...19989758831
molecular cloning and nucleotide sequence of cdna encoding the entire precursor of rat mitochondrial acetoacetyl-coa thiolase.cdna clones for rat mitochondrial acetoacetyl-coa thiolase were isolated and sequenced. the most 5'-extended clone (rt2-6) consisted of 1,460 bases and contained a 1,272-base open reading frame encoding a polypeptide of 424 amino acid residues. a coupled in vitro transcription/translation analysis of rt2-6 revealed that rt2-6 encodes the entire precursor of this enzyme. the amino-terminal sequence and amino acid composition of the purified enzyme agreed with the primary structure deduced from th ...19892478525
assessment of changes in microbial community structure during operation of an ammonia biofilter with molecular tools.biofiltration has been used for two decades to remove odors and various volatile organic and inorganic compounds in contaminated off-gas streams. although biofiltration is widely practiced, there have been few studies of the bacteria responsible for the removal of air contaminants in biofilters. in this study, molecular techniques were used to identify bacteria in a laboratory-scale ammonia biofilter. both 16s rrna and ammonia monooxygenase (amoa) genes were used to characterize the heterotrophi ...19989835577
flow cytometric analysis of the in situ accessibility of escherichia coli 16s rrna for fluorescently labeled oligonucleotide situ identification of whole fixed bacterial cells by hybridization with fluorescently labeled, rrna-targeted oligonucleotide probes is often limited by low signal intensities. in addition to an impermeability of the cell periphery and a low cellular rrna content, the three-dimensional structure of the ribosome may hinder the access of oligonucleotides to their target sites. until now, a systematic study on the accessibility of 16s rrna target sites had not been done. here, we report fluoresc ...19989835591
morphological and biochemical properties of a sphaerotilus sp. isolated from paper mill slimes.four strains of filamentous bacteria were isolated from slimes collected in different paper mill factories. morphological and physiological characterization of the isolates indicated an affiliation with the genus sphaerotilus. however, while the physiological properties of the isolates were almost identical, pronounced physiological differences between the isolates and sphaerotilus natans dsm 6575(t), dsm 565, and dsm 566 with respect to their ability to metabolize complex polysaccharides, sugar ...19999872774
poly-3-hydroxybutyrate degradation in rhizobium (sinorhizobium) meliloti: isolation and characterization of a gene encoding 3-hydroxybutyrate dehydrogenase.we have cloned and sequenced the 3-hydroxybutyrate dehydrogenase-encoding gene (bdha) from rhizobium (sinorhizobium) meliloti. the gene has an open reading frame of 777 bp that encodes a polypeptide of 258 amino acid residues (molecular weight 27,177, pi 6.07). the r. meliloti bdh protein exhibits features common to members of the short-chain alcohol dehydrogenase superfamily. bdha is the first gene transcribed in an operon that also includes xdha, encoding xanthine oxidase/dehydrogenase. transc ...19999922248
metabolic engineering of poly(3-hydroxyalkanoates): from dna to plastic.poly(3-hydroxyalkanoates) (phas) are a class of microbially produced polyesters that have potential applications as conventional plastics, specifically thermoplastic elastomers. a wealth of biological diversity in pha formation exists, with at least 100 different pha constituents and at least five different dedicated pha biosynthetic pathways. this diversity, in combination with classical microbial physiology and modern molecular biology, has now opened up this area for genetic and metabolic eng ...199910066830
the nh2-terminal 14-16 amino acids of mitochondrial and bacterial thiolases can direct mature ornithine carbamoyltransferase into mitochondria.unlike most mitochondrial matrix proteins, the mitochondrial 3-oxoacyl-coa thiolase [ec] is synthesized with no cleavable presequence and possesses information for mitochondrial targeting and import in the mature protein. this mitochondrial thiolase is homologous with the mature portion of peroxisomal 3-oxoacyl-coa thiolase and acetoacetyl-coa thiolase [ec] of zoogloea ramigera along the entire sequence. a hybrid gene encoding the nh2-terminal 16 residues (mallrgvfivaakrtp) of t ...19902332418
phylogenetic analysis of ara+ and ara- burkholderia pseudomallei isolates and development of a multiplex pcr procedure for rapid discrimination between the two biotypes.a burkholderia pseudomallei-like organism has recently been identified among some soil isolates of b. pseudomallei in an area with endemic melioidosis. this organism is almost identical to b. pseudomallei in terms of morphological and biochemical profiles, except that it differs in ability to assimilate l-arabinose. these ara+ isolates are also less virulent than the ara- isolates in animal models. in addition, clinical isolates of b. pseudomallei available to date are almost exclusively ara-. t ...199910325345
the reaction of acetyldithio-coa, a readily enolized analog of acetyl-coa with thiolase from zoogloea ramigera.acetyldithio-coa has been shown to be a competent nucleophilic substrate but not an electrophilic substrate for the claisen condensation catalyzed by thiolase, which normally dimerizes acetyl (ac)-coa to acetoacetyl-coa. acting as the nucleophile, the kcat/km for dithioacetyl-coa is comparable to that of ac-coa, the normal substrate. with acetoacetyl-pantetheine acetylating the thiolase to provide the electrophile, the kcat and kcat/km for the claisen condensation are 2.1 s-1 and 8.3 x 10(4) m-1 ...19902180945
biosynthetic thiolase from zoogloea ramigera. evidence for a mechanism involving cys-378 as the active site base.biosynthetic thiolase from zoogloea ramigera was inactivated with a mechanism-based inactivator, 3-pentynoyl-s-pantetheine-11-pivalate (3-pentynoyl-spp) where k1 = 1.25 mm and kinact = 0.26 min-1, 2,3-pentadienoyl-spp obtained from nonenzymatic rearrangement of 3-pentynoyl-spp where k1 = 1.54 mm and kinact = 1.9 min-1 and an affinity labeling reagent, acryl-spp. the results obtained with the alkynoyl and allenoyl inactivators are taken as evidence that thiolase from z. ramigera is able to cataly ...19911673680
intracellular degradation of poly(3-hydroxybutyrate) granules of zoogloea ramigera i-16-m.intracellular degradation of poly(3-hydroxybutyrate) (phb) in bacteria is not yet clear. the properties of the autodigestion of native phb granules from zoogloea ramigera i-16-m were examined. the release of d(-)-3-hydroxybutyrate was observed only at ph values higher than about 8.5 and at relatively high ionic strength (optimal concentration 200 mm nacl). triton x-100 and diisopropylfluorophosphate inhibited this reaction. addition of the supernatant fraction of z. ramigera did not increase the ...19921476778
the ntrb and ntrc genes are involved in the regulation of poly-3-hydroxybutyrate biosynthesis by ammonia in azospirillum brasilense sp7.azospirillum brasilense sp7 and its ntra (rpon), ntrbc, and ntrc mutants have been evaluated for their capabilities of poly-3-hydroxybutyrate (phb) accumulation in media with high and low ammonia concentrations. it was observed that the ntrbc and ntrc mutants can produce phb in both low- and high-c/n-ratio media, while no significant phb production was observed for the wild type or the ntra mutant in low-c/n-ratio media. further investigation by fermentation analysis indicated that the ntrbc and ...200010618211
biosynthetic thiolase from zoogloea ramigera. mutagenesis of the putative active-site base cys-378 to ser-378 changes the partitioning of the acetyl s-enzyme intermediate.the proposed active-site base cys-378 of thiolase, responsible for deprotonation of acetyl-coa, has been converted to a less acidic residue ser-378 by mutagenesis. comparison of the cd spectra and dimethyl suberimidate cross-linking experiments of the wild type, mutant ser-378, and gly-378 enzymes indicated that there have been no major conformational changes. the ser-378 enzyme retains 0.1% of the vmax of wild type in the direction of acetoacetyl-coa thiolytic cleavage and 0.07% of the vmax in ...19921353760
[phb (poly-beta-hydroxybutyrate) metabolism of zoogloea ramigera]. 19761034660
requirement for the enzymes acetoacetyl coenzyme a synthetase and poly-3-hydroxybutyrate (phb) synthase for growth of sinorhizobium meliloti on phb cycle intermediates.we have identified two sinorhizobium meliloti chromosomal loci affecting the poly-3-hydroxybutyrate degradation pathway. one locus was identified as the gene acsa, encoding acetoacetyl coenzyme a (acetoacetyl-coa) synthetase. analysis of the acsa nucleotide sequence revealed that this gene encodes a putative protein with a molecular weight of 72,000 that shows similarity to acetyl-coa synthetase in other organisms. acetyl-coa synthetase activity was not affected in cell extracts of glucose-grown ...200010735852
enzymatic synthesis of poly-beta-hydroxybutyrate in zoogloea ramigera.the enzyme activity synthesizing poly-beta-hydroxybutyrate (phb) was mainly localized in the phb-containing particulate fraction of zoogloea ramigera i-16-m, when it grew flocculatedly in a medium supplemented with glucose. on the other hand, the enzyme activity remained in the soluble fraction when the bacterium grew dispersedly in a glucose-starved medium. the soluble phb synthase activity became associated with the particulate fraction as phb synthesis was initiated on the addition of glucose ...19761015943
determination of the biosorption heats of heavy metal ions on zoogloea ramigera and rhizopus arrhizus.the biosorption of fe(iii), cr(vi), pb(ii), cu(ii) and ni(ii) ions on zoogloea ramigera (activated sludge bacterium) and rhizopus arrhizus (filamentous fungus) has been studied as a function of initial metal ion concentration and temperature. the applicability of the langmuir model for each metal-microorganism system has been tested at different temperatures. the enthalpy change for the biosorption process has been evaluated by using the langmuir constant b, related to the energy of adsorption. ...200010959085
purification and properties of beta-ketothiolase from zoogloea ramigera.beta-ketothiolase from zoogloea ramigera i-16-m was purified 140-fold to electrophoretic homogeneity. the bacterium appeared to contain a single isoenzyme of beta-ketothiolase with a molecular weight of 190 000, as determined by sephadex g-200 gel filtration. the monomer molecular weight was 44 000, as estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. the native enzyme thus appeared to be a tetramer with identical subunits. the enzyme showed a ph optimum ...197823736
an nadp-linked acetoacetyl coa reductase from zoogloea ramigera.zoogloea ramigera i-16 m was found to contain two stereospecific acetoacetyl coa reductases; one was nadp+-linked and d(-)-beta-hydroxybutyryl coa specific and the other was nad+-linked and l(+)-isomer specific. the nadp+-linked enzyme, purified approximately 150-fold, had a ph optimum for the reduction of acetoacetyl coa at 8.1, but no definite ph optimum for the oxidation for beta-hydroxybutyryl coa. the apparent michaelis constants for acetoacetyl coa and nadph were 8.3 and 21 micrometer, res ...197720866
alpha- and beta-proteobacteria control the consumption and release of amino acids on lake snow aggregates.we analyzed the composition of aggregate (lake snow)-associated bacterial communities in lake constance from 1994 until 1996 between a depth of 25 m and the sediment surface at 110 m by fluorescent in situ hybridization with rrna-targeted oligonucleotide probes of various specificity. in addition, we experimentally examined the turnover of dissolved amino acids and carbohydrates together with the microbial colonization of aggregates formed in rolling tanks in the lab. generally, between 40 and m ...200111157226
an extracellular poly(3-hydroxybutyrate) depolymerase from alcaligenes faecalis.a strain of alcaligenes faecalis t1, which was isolated from activated sludge, excreted an extracellular poly(3-hydroxybutyrate) depolymerase as it grew in a medium containing poly(3-hydroxybutyrate) as the sole carbon source. the molecular weight of the enzyme, purified from the culture medium to electrophoretic homogeneity, was 48 000 as determined by sephadex g-100 filtration, and 50 000 by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate. the ph optimum for the enz ...19827084231
degradation of aromatics and chloroaromatics by pseudomonas sp. strain b13: purification and characterization of 3-oxoadipate:succinyl-coenzyme a (coa) transferase and 3-oxoadipyl-coa thiolase.the degradation of 3-oxoadipate in pseudomonas sp. strain b13 was investigated and was shown to proceed through 3-oxoadipyl-coenzyme a (coa) to give acetyl-coa and succinyl-coa. 3-oxoadipate:succinyl-coa transferase of strain b13 was purified by heat treatment and chromatography on phenyl-sepharose, mono-q, and superose 6 gels. estimation of the native molecular mass gave a value of 115,000 +/- 5,000 da with a superose 12 column. polyacrylamide gel electrophoresis under denaturing conditions res ...200211741862
an nad-linked acetoacetyl-coa reductase from zoogloea ramigera nad-linked acetoacetyl-coa reductase of zoolgoea ramigera i-16-m was purified to electrophoretic homogeneity. in contrast to the d(-)-3-hydroxybutyryl-coa-specific nadp-linked acetoacetyl-coa reductase from the same bacterium [saito, t. et al (1977) arch. microbiol. 114, 211 - 217], the purified enzyme was strictly stereospecific to l(+)-3-hydroxybutyryl-coa, and was active not only with nad+ but also with nadp+, although nadp+ was less effective than nad+ as coenzyme. the enzyme showed a ph ...19817026239
an extracellular polysaccharide produced by zoogloea ramigera 115.a weakly acidic polysaccharide was purified from the extracellular zoogloeal matrix produced by zoogloeal ramigera 115. the purified polysaccharide was homogeneous as judged by sedimentation analysis, and the average molecular weight was estimated to be about 10(5) by gel permeation chromatography of the fully methylated preparation. the polysaccharide was composed of d-glucose, d-galactose and pyruvic acid in an approximate molar ratio 11:3:1.5. on the basis of methylation, periodate oxidation, ...19826281010
a mechanism of floc formation by zoogloea ramigera. 19665980995
production of extracellular polysaccharide matrix by zoogloea ramigera.zoogloea ramigera 115 synthesized large amounts of matrix polymer from fructose, galactose, glucose, lactose, mannose, soluble starch, and sucrose when these carbohydrates were used as supplements to a chemically defined medium. all of them supported polymer synthesis to the extent that cultures thickened to a gel. concentration of carbohydrate nutrients in the range 0.5 to 2.0% was not a critical factor in determining eventual total thickening to a gel, except in relation to the incubation time ...19715575568
enterococcus faecalis acetoacetyl-coenzyme a thiolase/3-hydroxy-3-methylglutaryl-coenzyme a reductase, a dual-function protein of isopentenyl diphosphate biosynthesis.many bacteria employ the nonmevalonate pathway for synthesis of isopentenyl diphosphate, the monomer unit for isoprenoid biosynthesis. however, gram-positive cocci exclusively use the mevalonate pathway, which is essential for their growth (e. i. wilding et al., j. bacteriol. 182:4319-4327, 2000). enzymes of the mevalonate pathway are thus potential targets for drug intervention. uniquely, the enterococci possess a single open reading frame, mvae, that appears to encode two enzymes of the mevalo ...200211914342
ania regulates reserve polymer accumulation and global protein expression in rhizobium etli.previously, it was reported that the oxidative capacity and ability to grow on carbon sources such as pyruvate and glucose were severely diminished in the rhizobium etli phac::omegasm(r)/sp(r) mutant car1, which is unable to synthesize poly-beta-hydroxybutyric acid (phb) (m. a. cevallos, s. encarnación, a. leija, y. mora, and j. mora, j. bacteriol. 178:1646-1654, 1996). by random tn5 mutagenesis of the phac strain, we isolated the mutants vem57 and vem58, both of which contained single tn5 inser ...200211914361
diversity and abundance of bacteria in an underground oil-storage cavity.microorganisms inhabiting subterranean oil fields have recently attracted much attention. since intact groundwater can easily be obtained from the bottom of underground oil-storage cavities without contamination by surface water, studies on such oil-storage cavities are expected to provide valuable information to understand microbial ecology of subterranean oil fields.200212197947
biodegradation of the polyketide toxin cercosporin.cercosporin is a non-host-specific polyketide toxin produced by many species of plant pathogens belonging to the genus cercospora. this red-pigmented, light-activated toxin is an important pathogenicity determinant for cercospora species. in this study, we screened 244 bacterial isolates representing 12 different genera for the ability to degrade cercosporin. cercosporin degradation was determined by screening for the presence of cleared zones surrounding colonies on cercosporin-containing cultu ...200212200262
purification and characterization of acetoacetyl-coa synthetase from zoogloea ramigera i-16-m.acetoacetyl-coa synthetase was purified to electrophoretic homogeneity from zoogloea ramigera i-16-m, a poly(3-hydroxybutyrate)-accumulating bacterium, which lacks 3-ketoacid coa-transferase. the purified enzyme had a specific activity of 52.2 mumol acetoacetyl-coa formed min-1 mg protein-1, which constituted a 680-fold purification compared to the crude extract, with a 5.1% yield. the enzyme absolutely required atp, coa, a monovalent cation (k+, rb+, cs+ or nh+4) and a divalent cation (mg2+, mn ...19827140777
antimicrobial activity of berberine--a constituent of mahonia aquifolium.the antimicrobial activity of the protoberberine alkaloid, berberine, isolated from mahonia aquifolium, was evaluated against 17 microorganisms including two gram-negative bacteria--pseudomonas aeruginosa and escherichia coli (both resistant and sensitive), two gram-positive bacteria--bacillus subtilis and staphylococcus aureus, zoogloea ramigera, six filamentous fungi--penicilium chrysogenum, aspergillus niger, aureobasidium pullulans (black and white strain), trichoderma viride (original green ...200212422513
the catalytic cycle of biosynthetic thiolase: a conformational journey of an acetyl group through four binding modes and two oxyanion holes.biosynthetic thiolase catalyzes the formation of acetoacetyl-coa from two molecules of acetyl-coa. this is a key step in the synthesis of many biological compounds, including steroid hormones and ketone bodies. the thiolase reaction involves two chemically distinct steps; during acyl transfer, an acetyl group is transferred from acetyl-coa to cys89, and in the claisen condensation step, this acetyl group is further transferred to a second molecule of acetyl-coa, generating acetoacetyl-coa. here, ...200212501183
purification and properties of d-beta-hydroxybutyrate dehydrogenase from zoogloea ramigera i-16-m.d(-)-beta-hydroxybutyrate dehydrogenase was purified from zoogloea ramigera i-16-m to electrophoretic homogeneity. the molecular weight of the enzyme as determined by sephadex g-200 gel filtration was 112,000, and the monomer molecular weight estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate was 28,000, indicating that the native enzyme is a tetramer with four identical subunits. the enzyme showed a ph optimum at 8.0 in the oxidation reaction, and a broad ...19817240131
synthesis of ethyl ( s)-4-chloro-3-hydroxybutanoate using fabg-homologues.this paper is a report on the successful application of bioinformatics to enzyme screening. the synthesis of ethyl ( s)-4-chloro-3-hydroxybutanoate (echb) by asymmetric reduction of ethyl 4-chloroacetoacetate (ecaa) using fabg-homologues was studied. beta-ketoacyl-acyl carrier protein reductases from both escherichia coli and bacillus subtilis, which are components of type ii fatty acid synthase, could reduce ecaa to ( s)-echb with 94-98% ee. furthermore, acetoacetyl-coa reductases (ars) from bo ...200312655455
isolation of the floc-forming organism zoogloea ramigera and its culture in complex and synthetic media. 196013724815
isolation, identification, and metabolic role of the sudanophilic granules of zoogloea ramigera.organisms isolated from activated sludge and identified as zoogloea ramigera accumulated large amounts of sudanophilic granules as the cultures flocculated. the granules were extracted by chloroform and precipitated with ether from acid-hydrolyzed cells. identification of the sudanophilic granules as poly-beta-hydroxybutyric acid (phb) was confirmed by physical, chemical, and infrared spectral analyses. the isolated polymer accounted for 12.0 to 50.5% of the dry weight of the cells. the polymer ...196514325883
respiration studies on the organic nitrogen preferences of zoogloea ramigera. 195514350612
the abundance of zoogloea ramigera in sewage treatment plants.zoogloea ramigera has long been considered the typical activated sludge bacterium responsible for the formation of activated sludge flocs. on the basis of the results of a comparative sequence analysis, we designed three oligonucleotide probes complementary to characteristic regions of the 16s rrnas of z. ramigera atcc 19544t (t = type strain) and two misclassified strains, z. ramigera atcc 25935 and atcc 19623. dissociation temperatures were determined, and probe specificities, as well as the p ...19957574608
characterization of a sterol carrier protein 2/3-oxoacyl-coa thiolase from the cotton leafworm (spodoptera littoralis): a lepidopteran mechanism closer to that in mammals than that in dipterans.numerous invertebrate species belonging to several phyla cannot synthesize sterols de novo and rely on a dietary source of the compound. scpx (sterol carrier protein 2/3-oxoacyl-coa thiolase) is a protein involved in the trafficking of sterols and oxidation of branched-chain fatty acids. we have isolated scpx protein from spodoptera littoralis (cotton leafworm) and have subjected it to limited amino acid sequencing. a reverse-transcriptase pcr-based approach has been used to clone the cdna (1.9 ...200415149283
bacteria obtained from a sequencing batch reactor that are capable of growth on dehydroabietic acid.eleven isolates capable of growth on the resin acid dehydroabietic acid (dha) were obtained from a sequencing batch reactor designed to treat a high-strength process stream from a paper mill. the isolates belonged to two groups, represented by strains dha-33 and dha-35, which were characterized. in the bioreactor, bacteria like dha-35 were more abundant than those like dha-33. the population in the bioreactor of organisms capable of growth on dha was estimated to be 1.1 x 10(6) propagules per ml ...19957793937
molecular systematics of the genus zoogloea and emendation of the genus.phylogenetic relationships among strains of zoogloea and related taxa were determined by 16s rdna sequencing and genomic dna hybridization techniques. the 16s rrna gene was amplified by the polymerase chain reaction with a pair of eubacterial consensus primers and sequenced directly by using an automated fluorescent dna sequencer. sequence comparisons and distance matrix tree analysis revealed that zoogloea ramigera iam 12136 (= n. c. dondero 106, type strain) and zoogloea sp. atcc 19324 formed ...19938240962
molecular analysis of microflora associated with dentoalveolar abscesses.the microflora associated with three dentoalveolar abscesses was determined by cultural and molecular methods. 16s rrna genes were randomly amplified by means of conserved eubacterial primers and cloned. restriction fragment length polymorphism analysis of the clones and amplified genes encoding 16s rrna from the cultured bacteria was used to detect putative unculturable bacteria. clones representative of five predominant groups of uncultured organisms were sequenced. two were identified as porp ...19968904410
16s rrna gene-based oligonucleotide microarray for environmental monitoring of the betaproteobacterial order "rhodocyclales".for simultaneous identification of members of the betaproteobacterial order "rhodocyclales" in environmental samples, a 16s rrna gene-targeted oligonucleotide microarray (rhc-phylochip) consisting of 79 probes was developed. probe design was based on phylogenetic analysis of available 16s rrna sequences from all cultured and as yet uncultured members of the "rhodocyclales." the multiple nested probe set was evaluated for microarray hybridization with 16s rrna gene pcr amplicons from 29 reference ...200515746340
quantitative molecular assay for fingerprinting microbial communities of wastewater and estrogen-degrading consortia.a quantitative fingerprinting method, called the real-time terminal restriction fragment length polymorphism (real-time-t-rflp) assay, was developed for simultaneous determination of microbial diversity and abundance within a complex community. the real-time-t-rflp assay was developed by incorporating the quantitative feature of real-time pcr and the fingerprinting feature of t-rflp analysis. the assay was validated by using a model microbial community containing three pure strains, an escherich ...200515746346
characterization of the dominant and rare members of a young hawaiian soil bacterial community with small-subunit ribosomal dna amplified from dna fractionated on the basis of its guanine and cytosine composition.the small-subunit ribosomal dna (rdna) diversity was found to be very high in a hawaiian soil community that might be expected to have lower diversity than the communities in continental soils because the hawaiian soil is geographically isolated and only 200 years old, is subjected to a constant climate, and harbors low plant diversity. since an underlying community structure could not be revealed by analyzing the total eubacterial rdna, we first fractionated the dna on the basis of guanine-plus ...19989546163
novel intracellular 3-hydroxybutyrate-oligomer hydrolase in wautersia eutropha h16.wautersia eutropha h16 (formerly ralstonia eutropha) mobilizes intracellularly accumulated poly(3-hydroxybutyrate) (phb) with intracellular poly(3-hydroxybutyrate) depolymerases. in this study, a novel intracellular 3-hydroxybutyrate-oligomer hydrolase (phazc) gene was cloned and overexpressed in escherichia coli. then phazc was purified and characterized. immunoblot analysis with polyclonal antiserum against phazc revealed that most phazc is present in the cytosolic fraction and a small amount ...200516030206
new chitosan-degrading strains that produce chitosanases similar to choa of mitsuaria chitosanitabida.the betaproteobacterium mitsuaria chitosanitabida (formerly matsuebacter chitosanotabidus) 3001 produces a chitosanase (choa) that is classified in glycosyl hydrolase family 80. while many chitosanase genes have been isolated from various bacteria to date, they show limited homology to the m. chitosanitabida 3001 chitosanase gene (choa). to investigate the phylogenetic distribution of chitosanases analogous to choa in nature, we identified 67 chitosan-degrading strains by screening and investiga ...200516151097
multiple beta-ketothiolases mediate poly(beta-hydroxyalkanoate) copolymer synthesis in ralstonia eutropha.polyhydroxyalkanoates (phas) are a class of carbon and energy storage polymers produced by numerous bacteria in response to environmental limitation. the type of polymer produced depends on the carbon sources available, the flexibility of the organism's intermediary metabolism, and the substrate specificity of the pha biosynthetic enzymes. ralstonia eutropha produces both the homopolymer poly-beta-hydroxybutyrate (phb) and, when provided with the appropriate substrate, the copolymer poly(beta-hy ...19989555876
genetic analysis of comamonas acidovorans polyhydroxyalkanoate synthase and factors affecting the incorporation of 4-hydroxybutyrate monomer.the polyhydroxyalkanoate (pha) synthase gene of comamonas acidovorans ds-17 (phacca) was cloned by using the synthase gene of alcaligenes eutrophus as a heterologous hybridization probe. complete sequencing of a 4.0-kbp smai-hindiii (sh40) subfragment revealed the presence of a 1,893-bp pha synthase coding region which was followed by a 1,182-bp beta-ketothiolase gene (phaaca). both the translated products of these genes showed significant identity, 51.1 and 74.2%, respectively, to the primary s ...19989726894
occurrence of zoogloea colonies and protozoans at different stages of sewage purification.the presence of fingered branch-bearing zoogloea has been noted on a number of occasions in the baroda sewage disposal works. samples of raw sewage, the effluent from the continuous flow settling basin, the raw sludge, the floating scum in the settling basin, the final secondary digested sludge, and the supernatant liquid from the secondary digester were kept without any disturbance in 1-liter pyrex glass beakers, which were loosely covered with petri dishes. scum was formed on the surface withi ...196716349712
psychrotolerant bacteria isolated from arctic soil that degrade polychlorinated biphenyls at low temperaturespsychrotolerant polychlorinated biphenyl (pcb)-degrading bacteria were isolated at 7 degreesc from pcb-contaminated arctic soil by using biphenyl as the sole organic carbon source. these isolates were distinguished from each other by differences in substrates that supported growth and substrates that were oxidized. 16s ribosomal dna sequences suggest that these isolates are most closely related to the genus pseudomonas. total removal of aroclor 1242, and rates of removal of selected pcb congener ...19989835569
cohn's crenothrix is a filamentous methane oxidizer with an unusual methane monooxygenase.135 years ago ferdinand cohn, the founder of bacteriology, microscopically observed a conspicuous filamentous bacterium with a complex life cycle and described it as crenothrix polyspora. this uncultured bacterium is infamous for mass developments in drinking water systems, but its phylogeny and physiology remained unknown. we show that c. polyspora is a gammaproteobacterium closely related to methanotrophs and capable of oxidizing methane. we discovered that c. polyspora encodes a phylogenetica ...200616452171
an additional regulatory gene for actinorhodin production in streptomyces lividans involves a lysr-type transcriptional regulator.the sequence of a 4.8-kbp dna fragment adjacent to the right-hand end of the actinorhodin biosynthetic (act) cluster downstream of actvb-orf6 from streptomyces coelicolor a3(2) reveals six complete open reading frames, named orf7 to orf12. the deduced amino acid sequences from orf7, orf10, and orf11 show significant similarities with the following products in the databases: a putative protein from the s. coelicolor scp3 plasmid, lysr-type transcriptional regulators, and proteins belonging to the ...199910400594
a biosynthetic thiolase in complex with a reaction intermediate: the crystal structure provides new insights into the catalytic mechanism.thiolases are ubiquitous and form a large family of dimeric or tetrameric enzymes with a conserved, five-layered alphabetaalphabetaalpha catalytic domain. thiolases can function either degradatively, in the beta-oxidation pathway of fatty acids, or biosynthetically. biosynthetic thiolases catalyze the biological claisen condensation of two molecules of acetyl-coa to form acetoacetyl-coa. this is one of the fundamental categories of carbon skeletal assembly patterns in biological systems and is t ...199910545327
toxicity studies in a chemical dye production industry in turkey.this study investigated the acute toxicity of chemical dye production industry wastewaters by traditional and enrichment toxicity tests and emphasized the importance of toxicity tests in wastewater discharge regulations. the enrichment toxicity tests are novel applications indicating whether there is potential toxicity or stimulation conditions. different organisms were used including bacteria (floc-zoogloea ramigera and coliform-escherichia coli bacteria), algae (chlorella vulgaris), fish (lepi ...200616950564
microarray-based analysis of microbial community rnas by whole-community rna amplification.a new approach, termed whole-community rna amplification (wcra), was developed to provide sufficient amounts of mrnas from environmental samples for microarray analysis. this method employs fusion primers (six to nine random nucleotides with an attached t7 promoter) for the first-strand synthesis. the shortest primer (t7n6s) gave the best results in terms of the yield and representativeness of amplification. about 1,200- to 1,800-fold amplification was obtained with amounts of the rna templates ...200717098911
microarray-based analysis of microbial community rnas by whole-community rna amplification.a new approach, termed whole-community rna amplification (wcra), was developed to provide sufficient amounts of mrnas from environmental samples for microarray analysis. this method employs fusion primers (six to nine random nucleotides with an attached t7 promoter) for the first-strand synthesis. the shortest primer (t7n6s) gave the best results in terms of the yield and representativeness of amplification. about 1,200- to 1,800-fold amplification was obtained with amounts of the rna templates ...200717098911
biosynthesis of novel exopolymers by aureobasidium pullulans.aureobasidium pullulans atcc 42023 was cultured under aerobic conditions with glucose, mannose, and glucose analogs as energy sources. the exopolymer extracts produced under these conditions were composed of glucose and mannose. the molar ratio of glucose to mannose in the exopolymer extract and the molecular weight of the exopolymer varied depending on the energy source and culture time. the glucose content of exopolymer extracts formed with glucose and mannose as the carbon sources was between ...199910583975
quantification of hyphomicrobium populations in activated sludge from an industrial wastewater treatment system as determined by 16s rrna analysis.the bacterial community structure of the activated sludge from a 25 million-gal-per-day industrial wastewater treatment plant was investigated using rrna analysis. 16s ribosomal dna (rdna) libraries were created from three sludge samples taken on different dates. partial rrna gene sequences were obtained for 46 rdna clones, and nearly complete 16s rrna sequences were obtained for 18 clones. seventeen of these clones were members of the beta subdivision, and their sequences showed high homology t ...200010698787
3-hydroxy-3-methylglutaryl-coenzyme a synthase reaction intermediates: detection of a covalent tetrahedral adduct by differential isotope shift 13c nuclear magnetic resonance spectroscopy.binding of [1,2-(13)c]acetyl-coa to wild-type 3-hydroxy-3-methylglutaryl-coenzyme a (hmg-coa) synthase is characterized by large upfield shifts for c1 (184 ppm, deltadelta = 20 ppm) and c2 (26 ppm, deltadelta = 7 ppm) resonances that are attributable to formation of the covalent [1,2 -(13)c]acetyl-s-enzyme reaction intermediate. nmr spectra of [1, 2-(13)c]acetyl-s-enzyme prepared in h(2)(16)o versus h(2)(18)o indicate a 0.055 ppm upfield shift of the c1 resonance in the presence of the heavier i ...200010727229
development of a continuous process for metal accumulation by zoogloea ramigera.biomass, mainly consisting of an acidic polysaccharide produced by zoogloea ramigera, has been used as an adsorbing agent in a continuous process for the recovery of metal. the adsorption of copper has been studied with respect to retention time, biomass concentration, and reaction ph, in order to determine the optimal conditions for copper recovery. the results indicate that the uptake of copper is rapid and efficient. about 0.17 g cu is adsorbed per gram of biomass within 10 min. at high bioma ...198418551736
increased mass transfer to microorganisms with fluid motion.the effect of fluid flow and laminar shear on bacterial uptake was examined under conditions representative of the fluid environment of unattached and attached cells in wastewater treatment bioreactors. laminar shear rates below 50 s(-1) did not increase leucine uptake by suspended cultures of zoogloea ramigera. however, leucine uptake by cells fixed in a flow field of approximately 1 mm s(-1) was 55-65% greater than uptake by suspended cells. enhanced microbial uptake with advective motion is c ...199018592492
crystallographic analysis of the reaction pathway of zoogloea ramigera biosynthetic thiolase.biosynthetic thiolases catalyze the biological claisen condensation of two acetyl-coa molecules to form acetoacetyl-coa. this is one of the fundamental categories of carbon skeletal assembly patterns in biological systems and is the first step in many biosynthetic pathways including those which generate cholesterol, steroid hormones and ketone body energy storage molecules. high resolution crystal structures of the tetrameric biosynthetic thiolase from zoogloea ramigera were determined (i) in th ...200010764581
cloning of an intracellular poly[d(-)-3-hydroxybutyrate] depolymerase gene from ralstonia eutropha h16 and characterization of the gene intracellular poly[d(-)-3-hydroxybutyrate] (phb) depolymerase gene (phaz) has been cloned from ralstonia eutropha h16 by the shotgun method, sequenced, and characterized. nucleotide sequence analysis of a 2.3-kbp dna fragment revealed an open reading frame of 1,260 bp, encoding a protein of 419 amino acids with a predicted molecular mass of 47,316 da. the crude extract of escherichia coli containing the phb depolymerase gene digested artificial amorphous phb granules and released mainly oligo ...200111114905
immunological methods for the study of zoogloea strains in natural environments.since zoogloea ramigera has been considered to be important in aerobic wastewater treatment, we have evaluated several methods for detecting and enumerating z. ramigera in water and wastewater samples. indirect immunoassay methods for the detection of zoogloea strains were developed using polyclonal antibodies against the cells or the isolated exocellular polymer (ep) of the neotype zoogloea ramigera strain 106 (atcc 19544). the primary antibodies reacted with the cells and the exopolymer associ ...200111791830
identification of an acetoacetyl coenzyme a synthetase-dependent pathway for utilization of l-(+)-3-hydroxybutyrate in sinorhizobium meliloti.d-(-)-3-hydroxybutyrate (dhb), the immediate depolymerization product of the intracellular carbon store poly-3-hydroxybutyrate (phb), is oxidized by the enzyme 3-hydroxybutyrate dehydrogenase to acetoacetate (aa) in the phb degradation pathway. externally supplied dhb can serve as a sole source of carbon and energy to support the growth of sinorhizobium meliloti. in contrast, wild-type s. meliloti is not able to utilize the l-(+) isomer of 3-hydroxybutyrate (lhb) as a sole source of carbon and e ...200211872708
reverse transcription of 16s rrna to monitor ribosome-synthesizing bacterial populations in the environment.identification and quantification of phylogenetically defined bacterial populations in the environment are often performed using molecular tools targeting 16s rrna. fluorescence in situ hybridization has been used to monitor the expression and processing of rrna by targeting the 3' tail of precursor 16s rrna. to expand this approach, we employed reverse transcription of total rna using primer s-d-bact-0338-a-a-18. length heterogeneity detected by slab gel analysis, denaturing high-performance li ...200919395563
evidence that ubiquinone is a required intermediate for rhodoquinone biosynthesis in rhodospirillum rubrum.rhodoquinone (rq) is an important cofactor used in the anaerobic energy metabolism of rhodospirillum rubrum. rq is structurally similar to ubiquinone (coenzyme q or q), a polyprenylated benzoquinone used in the aerobic respiratory chain. rq is also found in several eukaryotic species that utilize a fumarate reductase pathway for anaerobic respiration, an important example being the parasitic helminths. rq is not found in humans or other mammals, and therefore inhibition of its biosynthesis may p ...201019933361
evidence that ubiquinone is a required intermediate for rhodoquinone biosynthesis in rhodospirillum rubrum.rhodoquinone (rq) is an important cofactor used in the anaerobic energy metabolism of rhodospirillum rubrum. rq is structurally similar to ubiquinone (coenzyme q or q), a polyprenylated benzoquinone used in the aerobic respiratory chain. rq is also found in several eukaryotic species that utilize a fumarate reductase pathway for anaerobic respiration, an important example being the parasitic helminths. rq is not found in humans or other mammals, and therefore inhibition of its biosynthesis may p ...201019933361
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