| production of extracellular polysaccharide by zoogloea ramigera. | in batch cultures of zoogloea ramigera the maximum rate of exopolysaccharide synthesis occurred in a partly growth-linked process. the exopolysaccharide was attached to the cells as a capsule. the capsules were released from the cell walls after 150 h of cultivation, which caused the fermentation broth to be highly viscous. ultrasonication could be used to release capsular polysaccharide from the microbial cell walls. treatment performed after 48 to 66 h of cultivation revealed exopolysaccharide ... | 1982 | 16346138 |
| increased bacterial uptake of macromolecular substrates with fluid shear. | to investigate the effect of fluid shear on uptake rates of low-diffusivity macromolecular substrates by suspended cultures, we measured the uptake of two compounds as models of macromolecules, a protein (bovine serum albumin [bsa]) and a polysaccharide (dextran), using pure cultures of zoogloea ramigera and escherichia coli, respectively. oxygen utilization rates of stirred samples grown on bsa and dextran were 2.3 and 2.9 times higher, respectively, than those of undisturbed (still) samples. u ... | 1991 | 16348577 |
| 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 ... | 1967 | 16349712 |
| 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 ... | 2010 | 19933361 |
| 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 ... | 2010 | 19933361 |
| 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 ... | 2005 | 16151097 |
| shinella granuli gen. nov., sp. nov., and proposal of the reclassification of zoogloea ramigera atcc 19623 as shinella zoogloeoides sp. nov. | the taxonomic position of a novel bacterial strain, ch06t, isolated from an upflow anaerobic sludge blanket reactor was determined. strain ch06t was gram-negative, aerobic, motile and oxidase- and catalase-positive. a comparative 16s rrna gene sequence analysis showed a clear affiliation of strain ch06t to the alphaproteobacteria and it was most closely related to zoogloea ramigera atcc 19623 and mycoplana dimorpha iam 13154t (97.9 and 96.3% sequence similarity, respectively). the major respirat ... | 2006 | 16449455 |
| 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 ... | 2006 | 16452171 |
| 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 ... | 2006 | 16950564 |
| zoogloea oryzae sp. nov., a nitrogen-fixing bacterium isolated from rice paddy soil, and reclassification of the strain atcc 19623 as crabtreella saccharophila gen. nov., sp. nov. | two strains of free-living diazotrophs isolated from soil from a rice paddy field were characterized by using a polyphasic approach. the novel strains, a-7t and a-4, were found to be very closely related, with 99.9% 16s rrna gene sequence similarity and a dna-dna hybridization value of 89.5%, suggesting that they represent a single species. 16s rrna gene sequence analyses indicated that the two strains fell within the zoogloea lineage, with less than 96.7 % sequence similarity to other zoogloea ... | 2006 | 16514038 |
| isoprenoid biosynthesis: the evolution of two ancient and distinct pathways across genomes. | isopentenyl diphosphate (ipp) is the central intermediate in the biosynthesis of isoprenoids, the most ancient and diverse class of natural products. two distinct routes of ipp biosynthesis occur in nature: the mevalonate pathway and the recently discovered deoxyxylulose 5-phosphate (dxp) pathway. the evolutionary history of the enzymes involved in both routes and the phylogenetic distribution of their genes across genomes suggest that the mevalonate pathway is germane to archaebacteria, that th ... | 2000 | 11078528 |
| microbial community structure of activated sludge during aerobic granulation in an annular gap bioreactor. | a novel annular gap reactor was designed to create a controlled shear environment in which aerobic granular sludge could be developed. the bacterial and eukaryal community structures during two aerobic granular sludge experiments were tracked using denaturing gradient gel electrophoresis (dgge). the first granule cultivation experiment, using an organic loading rate of 1.6 kg/m3d cod, resulted in biomass that was dominated by filamentous bacteria and zoogloea ramigera colonies. a second experime ... | 2006 | 16898146 |
| amyloid-like adhesins produced by floc-forming and filamentous bacteria in activated sludge. | amyloid proteins (fimbriae or other microbial surface-associated structures) are expressed by many types of bacteria, not yet identified, in biofilms from various habitats, where they likely are of key importance to biofilm formation and biofilm properties. as these amyloids are potentially of great importance to the floc properties in activated sludge wastewater treatment plants (wwtp), the abundance of amyloid adhesins in activated sludge flocs from different wwtp and the identity of bacteria ... | 2008 | 18192426 |
| selective phospholipid methanolysis catalyzed by a weakly acidic microbial polysaccharide, zooglan. | zooglan, a weakly acidic exopolysaccharide produced by zoogloea ramigera 115, catalyzed the preferential methanolysis of phospatidylcholine compared to other phospholipids when the reaction was carried out in pure methanol at 30 degrees c. the reaction was monitored by thin-layer chromatography (tlc) as well as (1)h and (31)p nuclear magnetic resonance (nmr) spectrometry. zooglan enhanced the rate of methanolysis of dipalmitoylphosphatidylcholine (dppc) up to about 170-fold compared to controls ... | 2008 | 18439992 |
| accumulation of heavy-metal ions by zoogloea ramigera. | biomass has been produced from glucose using the organism zoogloea ramigera 115. this biomass has been used to remove copper, cadmium, and uranyl ions from water solutions. the metal uptake was studied with two different methods: either by spectrophotometric measurements on the solutions after flocculation or by potentiometric measurements with amalgam electrodes in order to follow the entire complex formation. the metal-biopolymer interaction in 0.1m naclo(4) is practically the same as when no ... | 1984 | 18551732 |
| 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 ... | 2004 | 15149283 |
| stratification of activity and bacterial community structure in biofilms grown on membranes transferring oxygen. | previous studies have shown that membrane-aerated biofilm (mab) reactors can simultaneously remove carbonaceous and nitrogenous pollutants from wastewater in a single reactor. oxygen is provided to mabs through gas-permeable membranes such that the region nearest the membrane is rich in oxygen but low in organic carbon, whereas the outer region of the biofilm is void of oxygen but rich in organic carbon. in this study, mabs were grown under similar conditions but at two different fluid velocitie ... | 2004 | 15066788 |
| 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 ... | 2007 | 17098911 |
| 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 ... | 2007 | 17098911 |
| the sulfur atoms of the substrate coa and the catalytic cysteine are required for a productive mode of substrate binding in bacterial biosynthetic thiolase, a thioester-dependent enzyme. | thioesters are more reactive than oxoesters, and thioester chemistry is important for the reaction mechanisms of many enzymes, including the members of the thiolase superfamily, which play roles in both degradative and biosynthetic pathways. in the reaction mechanism of the biosynthetic thiolase, the thioester moieties of acetyl-coa and the acetylated catalytic cysteine react with each other, forming the product acetoacetyl-coa. although a number of studies have been carried out to elucidate the ... | 2008 | 19016856 |
| 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 ... | 2009 | 19395563 |
| enzymes of the mevalonate pathway of isoprenoid biosynthesis. | the mevalonate pathway accounts for conversion of acetyl-coa to isopentenyl 5-diphosphate, the versatile precursor of polyisoprenoid metabolites and natural products. the pathway functions in most eukaryotes, archaea, and some eubacteria. only recently has much of the functional and structural basis for this metabolism been reported. the biosynthetic acetoacetyl-coa thiolase and hmg-coa synthase reactions rely on key amino acids that are different but are situated in active sites that are simila ... | 2010 | 20932952 |
| effect of temperature and cycle length on microbial competition in phb-producing sequencing batch reactor. | the impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (phb)-producing populations enriched in feast-famine sequencing batch reactors (sbrs) was investigated at temperatures of 20 °c and 30 °c, and in a cycle length range of 1-18 h. in this study, the microbial community structure of the phb-producing enrichments was found to be strongly dependent on temperature, but not on cycle length. zoogloea and plasticicumulans acidivorans dominated the sbrs operate ... | 2010 | 21107441 |
| effect of temperature and cycle length on microbial competition in phb-producing sequencing batch reactor. | the impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (phb)-producing populations enriched in feast-famine sequencing batch reactors (sbrs) was investigated at temperatures of 20 °c and 30 °c, and in a cycle length range of 1-18 h. in this study, the microbial community structure of the phb-producing enrichments was found to be strongly dependent on temperature, but not on cycle length. zoogloea and plasticicumulans acidivorans dominated the sbrs operate ... | 2010 | 21107441 |
| detection and prevention of enhanced biological phosphorus removal deterioration caused by zoogloea overabundance. | a sequencing batch reactor was operated in the conventional anaerobic-aerobic mode for enhanced biological phosphorus removal using acetate as the sole substrate. despite the nutrients concentrations in the influent being high enough to satisfy the biological requirements, zoogloea ramigera managed to grow in the system until it had negative effects on the process performance. the excess of exocellular polymeric material produced by this microorganism contributed to a viscous bulking phenomenon ... | 2008 | 18610543 |
| formation of se (0) nanoparticles by duganella sp. and agrobacterium sp. isolated from se-laden soil of north-east punjab, india. | selenium (se) is an essential trace element, but is toxic at high concentrations. depending upon the geological background, the land use or on anthropogenic pollution, different amounts of se may be present in soil. its toxicity is related to the oxyanions selenate and selenite as they are water soluble and bioavailable. microorganisms play an important role in se transformations in soil and its cycling in the environment by transforming water-soluble oxyanions into water insoluble, non-toxic el ... | 2012 | 22607265 |
| structural classification and properties of ketoacyl synthases. | ketoacyl synthases (kss) catalyze condensing reactions combining acyl-coa or acyl-acyl carrier protein (acp) with malonyl-coa to form 3-ketoacyl-coa, or with malonyl-acp to form 3-ketoacyl-acp. in each case the resulting acyl chain is two carbon atoms longer than before, and co(2) and either coa or acp are formed. kss also join other activated molecules in the polyketide synthesis cycle. our classification of kss by their primary and tertiary structures instead of by their substrates and the rea ... | 2011 | 21830247 |
| fractal dimensions and porosities of zoogloea ramigera and saccharomyces cerevisae aggregates. | the fractal nature microbial aggregates is a function of the type of microorganism and mixing conditions used to develop aggregates. we determined fractal dimensions from length-projected area (d(2)) and length-number scaling (d(3)) relationships. aggregates of zoogloea ramigera developed in rotating test tubes were both surface and mass fractals, with fractal dimensions of d(2) = 1.69 +/- 0.11 and d(3)= 1.79 +/- 0.28 (+/-standard deviation), respectively. when we grew this bacteria in a bench-t ... | 1991 | 18600775 |
| expression, identification and purification of dictyostelium acetoacetyl-coa thiolase expressed in escherichia coli. | acetoacetyl-coa thiolase (at) is an enzyme that catalyses the coa-dependent thiolytic cleavage of acetoacetyl-coa to yield 2 molecules of acetyl-coa, or the reverse condensation reaction. a full-length cdna clone pbsgt-3, which has homology to known thiolases, was isolated from dictyostelium cdna library. expression of the protein encoded in pbsgt-3 in escherichia coli, its thiolase enzyme activity, and the amino acid sequence homology search revealed that pbsgt-3 encodes an at. the recombinant ... | 2010 | 21209787 |
| coenzyme a-free activity, crystal structure, and rational engineering of a promiscuous β-ketoacyl thiolase from ralstonia eutropha. | thiolases catalyze the formation of carbon-carbon bonds in diverse biosynthetic pathways. the promiscuous β-ketoacyl thiolase b of ralstonia eutropha (rebktb) has been utilized in the in vivo conversion of coenzyme a (coa)-linked precursors such as acetyl-coa and glycolyl-coa into β-hydroxy acids, including the pharmaceutically-important 3,4-dihydroxybutyric acid. such thiolases could serve as powerful carbon-carbon bond-forming biocatalysts in vitro if handles less costly than coa were employab ... | 2015 | 26494979 |
| recovery of humic-reducing bacteria from a diversity of environments. | to evaluate which microorganisms might be responsible for microbial reduction of humic substances in sedimentary environments, humic-reducing bacteria were isolated from a variety of sediment types. these included lake sediments, pristine and contaminated wetland sediments, and marine sediments. in each of the sediment types, all of the humic reducers recovered with acetate as the electron donor and the humic substance analog, 2,6-anthraquinone disulfonate (aqds), as the electron acceptor were m ... | 1998 | 9546186 |
| expression, identification and purification of dictyostelium acetoacetyl-coa thiolase expressed in escherichia coli. | acetoacetyl-coa thiolase (at) is an enzyme that catalyses the coa-dependent thiolytic cleavage of acetoacetyl-coa to yield 2 molecules of acetyl-coa, or the reverse condensation reaction. a full-length cdna clone pbsgt-3, which has homology to known thiolases, was isolated from dictyostelium cdna library. expression of the protein encoded in pbsgt-3 in escherichia coli, its thiolase enzyme activity, and the amino acid sequence homology search revealed that pbsgt-3 encodes an at. the recombinant ... | 2010 | 21209787 |
| 454 pyrosequencing reveals bacterial diversity of activated sludge from 14 sewage treatment plants. | activated sludge (as) contains highly complex microbial communities. in this study, pcr-based 454 pyrosequencing was applied to investigate the bacterial communities of as samples from 14 sewage treatment plants of asia (mainland china, hong kong, and singapore), and north america (canada and the united states). a total of 259 k effective sequences of 16s rrna gene v4 region were obtained from these as samples. these sequences revealed huge amount of operational taxonomic units (otus) in as, tha ... | 2011 | 22170428 |
| cultivation of denitrifying bacteria: optimization of isolation conditions and diversity study. | an evolutionary algorithm was applied to study the complex interactions between medium parameters and their effects on the isolation of denitrifying bacteria, both in number and in diversity. growth media with a ph of 7 and a nitrogen concentration of 3 mm, supplemented with 1 ml of vitamin solution but not with sodium chloride or riboflavin, were the most successful for the isolation of denitrifiers from activated sludge. the use of ethanol or succinate as a carbon source and a molar c/n ratio ... | 2006 | 16597968 |
| 454 pyrosequencing reveals bacterial diversity of activated sludge from 14 sewage treatment plants. | activated sludge (as) contains highly complex microbial communities. in this study, pcr-based 454 pyrosequencing was applied to investigate the bacterial communities of as samples from 14 sewage treatment plants of asia (mainland china, hong kong, and singapore), and north america (canada and the united states). a total of 259 k effective sequences of 16s rrna gene v4 region were obtained from these as samples. these sequences revealed huge amount of operational taxonomic units (otus) in as, tha ... | 2011 | 22170428 |
| 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 ... | 1984 | 18551736 |
| 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 ... | 1990 | 18592492 |
| group ii intron protein localization and insertion sites are affected by polyphosphate. | mobile group ii introns consist of a catalytic intron rna and an intron-encoded protein with reverse transcriptase activity, which act together in a ribonucleoprotein particle to promote dna integration during intron mobility. previously, we found that the lactococcus lactis ll.ltrb intron-encoded protein (ltra) expressed alone or with the intron rna to form ribonucleoprotein particles localizes to bacterial cellular poles, potentially accounting for the intron's preferential insertion in the or ... | 2008 | 18593213 |
| electroactivity of phototrophic river biofilms and constitutive cultivable bacteria. | electroactivity is a property of microorganisms assembled in biofilms that has been highlighted in a variety of environments. this characteristic was assessed for phototrophic river biofilms at the community scale and at the bacterial population scale. at the community scale, electroactivity was evaluated on stainless steel and copper alloy coupons used both as biofilm colonization supports and as working electrodes. at the population scale, the ability of environmental bacterial strains to cata ... | 2011 | 21642402 |
| propionate oxidation by and methanol inhibition of anaerobic ammonium-oxidizing bacteria. | anaerobic ammonium oxidation (anammox) is a recently discovered microbial pathway and a cost-effective way to remove ammonium from wastewater. anammox bacteria have been described as obligate chemolithoautotrophs. however, many chemolithoautotrophs (i.e., nitrifiers) can use organic compounds as a supplementary carbon source. in this study, the effect of organic compounds on anammox bacteria was investigated. it was shown that alcohols inhibited anammox bacteria, while organic acids were convert ... | 2005 | 15691967 |
| identification of the viridicatumtoxin and griseofulvin gene clusters from penicillium aethiopicum. | penicillium aethiopicum produces two structurally interesting and biologically active polyketides: the tetracycline-like viridicatumtoxin 1 and the classic antifungal agent griseofulvin 2. here, we report the concurrent discovery of the two corresponding biosynthetic gene clusters (vrt and gsf) by 454 shotgun sequencing. gene deletions confirmed that two nonreducing pkss (nrpkss), vrta and gsfa, are required for the biosynthesis of 1 and 2, respectively. both pkss share similar domain architectu ... | 2010 | 20534346 |
| a genomic perspective on a new bacterial genus and species from the alcaligenaceae family, basilea psittacipulmonis. | a novel gram-negative, non-haemolytic, non-motile, rod-shaped bacterium was discovered in the lungs of a dead parakeet (melopsittacus undulatus) that was kept in captivity in a petshop in basel, switzerland. the organism is described with a chemotaxonomic profile and the nearly complete genome sequence obtained through the assembly of short sequence reads. | 2014 | 24581117 |
| life and death of deep-sea vents: bacterial diversity and ecosystem succession on inactive hydrothermal sulfides. | hydrothermal chimneys are a globally dispersed habitat on the seafloor associated with mid-ocean ridge (mor) spreading centers. active, hot, venting sulfide structures from mors have been examined for microbial diversity and ecology since their discovery in the mid-1970s, and recent work has also begun to explore the microbiology of inactive sulfides--structures that persist for decades to millennia and form moderate to massive deposits at and below the seafloor. here we used tag pyrosequencing ... | 2012 | 22275502 |
| purification and characterization of olea from xanthomonas campestris and demonstration of a non-decarboxylative claisen condensation reaction. | olea catalyzes the condensation of fatty acyl groups in the first step of bacterial long-chain olefin biosynthesis, but the mechanism of the condensation reaction is controversial. in this study, olea from xanthomonas campestris was expressed in escherichia coli and purified to homogeneity. the purified protein was shown to be active with fatty acyl-coa substrates that ranged from c(8) to c(16) in length. with limiting myristoyl-coa (c(14)), 1 mol of the free coenzyme a was released/mol of myris ... | 2011 | 21266575 |
| assessment of bacterial and structural dynamics in aerobic granular biofilms. | aerobic granular sludge (ags) is based on self-granulated flocs forming mobile biofilms with a gel-like consistence. bacterial and structural dynamics from flocs to granules were followed in anaerobic-aerobic sequencing batch reactors (sbr) fed with synthetic wastewater, namely a bubble column (bc-sbr) operated under wash-out conditions for fast granulation, and two stirred-tank enrichments of accumulibacter (pao-sbr) and competibacter (gao-sbr) operated at steady-state. in the bc-sbr, granules ... | 2013 | 23847600 |
| cloning, expression, purification, crystallization and x-ray crystallographic analysis of β-ketothiolase b from ralstonia eutropha h16. | polyhydroxyalkanoates are linear polyesters that are produced by bacterial fermentation and are used as biodegradable bioplastics. β-ketothiolase b (bktb) from ralstonia eutropha (rebktb) is a key enzyme for the production of various types of copolymers by catalyzing the condensation reactions of acetyl-coa with propionyl-coa and butyryl-coa. the rebktb protein was crystallized using the hanging-drop vapour-diffusion method in the presence of 25% polyethylene glycol 3350, 0.1 m bis-tris ph 6.5, ... | 2014 | 24598917 |
| functional characterization of thiolase-encoding genes from xanthophyllomyces dendrorhous and their effects on carotenoid synthesis. | the basidiomycetous yeast xanthophyllomyces dendrorhous has been described as a potential biofactory for terpenoid-derived compounds due to its ability to synthesize astaxanthin. functional knowledge of the genes involved in terpenoid synthesis would create opportunities to enhance carotenoid production. a thiolase enzyme catalyzes the first step in terpenoid synthesis. | 2016 | 27871246 |
| increasing the production of (r)-3-hydroxybutyrate in recombinant escherichia coli by improved cofactor supply. | in a recently discovered microorganism, halomonas boliviensis, polyhydroxybutyrate production was extensive and in contrast to other phb producers, contained a set of alleles for the enzymes of this pathway. also the monomer, (r)-3-hydroxybutyrate (3hb), possesses features that are interesting for commercial production, in particular the synthesis of fine chemicals with chiral specificity. production with a halophilic organism is however not without serious drawbacks, wherefore it was desirable ... | 2016 | 27245326 |
| performance assessment of full-scale wastewater treatment plants based on seasonal variability of microbial communities via high-throughput sequencing. | microbial communities of activated sludge (as) play a key role in the performance of wastewater treatment processes. however, seasonal variability of microbial population in varying as-based processes has been poorly correlated with operation of full-scale wastewater treatment systems (wwtss). in this paper, significant seasonal variability of as microbial communities in eight wwtss located in the city of guangzhou were revealed in terms of 16s rrna-based miseq sequencing. furthermore, variation ... | 2016 | 27049964 |
| flocculation-related gene identification by whole-genome sequencing of thauera aminoaromatica mz1t floc-defective mutants. | thauera aminoaromatica mz1t, a floc-forming bacterium isolated from an industrial activated-sludge wastewater treatment plant, overproduces exopolysaccharide (eps), leading to viscous bulking. this phenomenon results in poor sludge settling and dewatering during the clarification process. to identify genes responsible for bacterial flocculation, a whole-genome phenotypic-sequencing technique was applied. genomic dna of mz1t flocculation-deficient mutants was subjected to massively parallel seque ... | 2016 | 26712552 |
| microbial structure and nitrogen compound conversions in aerobic granular sludge reactors with non-aeration phases and acetate pulse feeding. | a technological system was developed for efficient nitrogen removal from real digester supernatant in a single reactor with shortened aeration to increase the economical aspects of wastewater treatment. the supernatant (600 mg tkn/l, low cod/n ratio of 2.2) was treated in batch reactors with aerobic granules (gsbrs) to test how one, two, or three non-aeration phases and acetate pulse feeding in the cycle affect the morphological and microbial properties of biomass. introduction of one non-aerati ... | 2016 | 27662853 |
| fada5 a thiolase from mycobacterium tuberculosis: a steroid-binding pocket reveals the potential for drug development against tuberculosis. | with the exception of hiv, tuberculosis (tb) is the leading cause of mortality among infectious diseases. the urgent need to develop new antitubercular drugs is apparent due to the increasing number of drug-resistant mycobacterium tuberculosis (mtb) strains. proteins involved in cholesterol import and metabolism have recently been discovered as potent targets against tb. fada5, a thiolase from mtb, is catalyzing the last step of the β-oxidation reaction of the cholesterol side-chain degradation ... | 2014 | 25482540 |
| fada5 a thiolase from mycobacterium tuberculosis: a steroid-binding pocket reveals the potential for drug development against tuberculosis. | with the exception of hiv, tuberculosis (tb) is the leading cause of mortality among infectious diseases. the urgent need to develop new antitubercular drugs is apparent due to the increasing number of drug-resistant mycobacterium tuberculosis (mtb) strains. proteins involved in cholesterol import and metabolism have recently been discovered as potent targets against tb. fada5, a thiolase from mtb, is catalyzing the last step of the β-oxidation reaction of the cholesterol side-chain degradation ... | 2014 | 25482540 |
| haloarchaeal-type β-ketothiolases involved in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesis in haloferax mediterranei. | the key enzymes for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (phbv) biosynthesis in haloarchaea have been identified except the β-ketothiolase(s), which condense two acetyl coenzyme a (acetyl-coa) molecules to acetoacetyl-coa, or one acetyl-coa and one propionyl-coa to 3-ketovaleryl-coa. whole-genome analysis has revealed eight potential β-ketothiolase genes in the haloarchaeon haloferax mediterranei, among which the phbv-specific bktb and phaa were identified by gene knockout and complement ... | 2013 | 23793631 |
| changes in microbial community structure in the wake of hurricanes katrina and rita. | hurricanes have the potential to alter the structures of coastal ecosystems and generate pathogen-laden floodwaters thatthreaten public health. to examine the impact of hurricanes on urban systems, we compared microbial community structures in samples collected after hurricane katrina and before and after hurricane rita. we extracted environmental dna and sequenced small-subunit rrna (ssu rrna) gene clone libraries to survey microbial communities in floodwater, water, and sediment samples collec ... | 2008 | 19174873 |
| the sterol carrier protein 2/3-oxoacyl-coa thiolase (scpx) is involved in cholesterol uptake in the midgut of spodoptera litura: gene cloning, expression, localization and functional analyses. | sterol carrier protein-2/3-oxoacyl-coa thiolase (scpx) gene has been suggested to be involved in absorption and transport of cholesterol. cholesterol is a membrane component and is a precursor of ecdysteroids, but cannot be synthesized de novo in insects. however, a direct association between scpx gene expression, cholesterol absorption and development in lepidopteran insects remains to be experimentally demonstrated. | 2009 | 19912624 |
| pyrosequencing analysis of bacterial diversity in 14 wastewater treatment systems in china. | to determine if there is a core microbial community in the microbial populations of different wastewater treatment plants (wwtps) and to investigate the effects of wastewater characteristics, operational parameters, and geographic locations on microbial communities, activated sludge samples were collected from 14 wastewater treatment systems located in 4 cities in china. high-throughput pyrosequencing was used to examine the 16s rrna genes of bacteria in the wastewater treatment systems. our res ... | 2012 | 22843531 |
| 3-hydroxybutyrate oligomer hydrolase and 3-hydroxybutyrate dehydrogenase participate in intracellular polyhydroxybutyrate and polyhydroxyvalerate degradation in paracoccus denitrificans. | genes encoding 3-hydroxybutyrate oligomer hydrolase (phazc) and 3-hydroxybutyrate dehydrogenase (hbd) were isolated from paracoccus denitrificans. phazc and hbd were overproduced as his-tagged proteins in escherichia coli and purified by affinity and gel filtration chromatography. purified his-tagged proteins had molecular masses of 31 kda and 120 kda (a tetramer of 29-kda subunits). the his-tagged phazc hydrolyzed not only 3-hydroxybutyrate oligomers but also 3-hydroxyvalerate oligomers. the hi ... | 2014 | 24271169 |
| crystal structure of a monomeric thiolase-like protein type 1 (tlp1) from mycobacterium smegmatis. | an analysis of the mycobacterium smegmatis genome suggests that it codes for several thiolases and thiolase-like proteins. thiolases are an important family of enzymes that are involved in fatty acid metabolism. they occur as either dimers or tetramers. thiolases catalyze the claisen condensation of two acetyl-coenzyme a molecules in the synthetic direction and the thiolytic cleavage of 3-ketoacyl-coenzyme a molecules in the degradative direction. some of the m. smegmatis genes have been annotat ... | 2012 | 22844533 |
| redox-switch regulatory mechanism of thiolase from clostridium acetobutylicum. | thiolase is the first enzyme catalysing the condensation of two acetyl-coenzyme a (coa) molecules to form acetoacetyl-coa in a dedicated pathway towards the biosynthesis of n-butanol, an important solvent and biofuel. here we elucidate the crystal structure of clostridium acetobutylicum thiolase (cathl) in its reduced/oxidized states. cathl, unlike those from other aerobic bacteria such as escherichia coli and zoogloea ramegera, is regulated by the redox-switch modulation through reversible disu ... | 2015 | 26391388 |
| impacts of different nanoparticles on functional bacterial community in activated sludge. | rapidly developing industry raises concerns about the environmental impacts of nanoparticles, but the effects of inorganic nanoparticles on functional bacterial community in wastewater treatment remain unclear. the discriminated effects of silver nanoparticles (ag-np) and zinc oxide nanoparticles (zno-np) in a simulated sequencing batch reactor (sbr) system were therefore evaluated by the rna-based terminal restricted fragment length polymorphism (t-rflp), 16s rcdna gene clone library and real-t ... | 2014 | 24280055 |
| the crystal structure of human mitochondrial 3-ketoacyl-coa thiolase (t1): insight into the reaction mechanism of its thiolase and thioesterase activities. | crystal structures of human mitochondrial 3-ketoacyl-coa thiolase (ht1) in the apo form and in complex with coa have been determined at 2.0 å resolution. the structures confirm the tetrameric quaternary structure of this degradative thiolase. the active site is surprisingly similar to the active site of the zoogloea ramigera biosynthetic tetrameric thiolase (pdb entries 1dm3 and 1m1o) and different from the active site of the peroxisomal dimeric degradative thiolase (pdb entries 1afw and 2iik). ... | 2014 | 25478839 |
| zoogloea oleivorans sp. nov., a floc-forming, petroleum hydrocarbon-degrading bacterium isolated from biofilm. | a floc-forming, gram-stain-negative, petroleum hydrocarbon-degrading bacterial strain, designated buc(t), was isolated from a petroleum hydrocarbon-contaminated site in hungary. phylogenetic analysis based on 16s rrna gene sequences revealed that strain buc(t) formed a distinct phyletic lineage within the genus zoogloea. its closest relative was found to be zoogloea caeni emb43(t) (97.2% 16s rrna gene sequence similarity) followed by zoogloea oryzae a-7(t) (95.9%), zoogloea ramigera atcc 19544(t ... | 2015 | 25342113 |
| crystal structure and biochemical characterization of beta-keto thiolase b from polyhydroxyalkanoate-producing bacterium ralstonia eutropha h16. | rebktb is a β-keto thiolase from ralstonia eutropha h16 that catalyzes condensation reactions between acetyl-coa with acyl-coa molecules that contains different numbers of carbon atoms, such as acetyl-coa, propionyl-coa, and butyryl-coa, to produce valuable bioproducts, such as polyhydroxybutyrate, polyhydroxybutyrate-hydroxyvalerate, and hexanoate. we solved a crystal structure of rebktb at 2.3å, and the overall structure has a similar fold to that of type ii biosynthetic thiolases, such as phb ... | 2014 | 24462871 |