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cyclic pathway of formaldehyde oxidation in pseudomonas oleovorans.operation of the dissimilatory hexulose phosphate cycle of formaldehyde oxidation in pseudomonas oleovarans has been directly confirmed. extracts of this typical facultative methylotroph catalyze the formation of 14co2 from 14c-formaldehyde. the process depends on the presence of ribose-5-phosphate, nadp or nad, and is linear in time. oxidation of formaldehyde via formate to co2 is of a minor importance in the energy metabolism of the methylotroph.197723487
[pyruvate and phosphoenolpyruvate carboxylase in methylotrophs].the activity of pyruvate and phosphoenolpyruvate carboxylases was determined in cell extracts of obligate and facultative methylotrophs which metabolized monocarbon reduced compounds via different pathways. phosphoenolpyruvate carboxylase was found to be the only enzyme responsible for the high level of co2 fixation by methylotrophs with the serine pathway (methylosinus trichosporium, hyphomicrobium vulgare, pseudomonas methylica). methylotrophs with the hexulose phosphate pathway mehylobacter c ...1979108526
fatty acid omega-hydroxylase (alkane hydroxylase) from pseudomonas oleovorans. 1978713843
physiological function of the pseudomonas putida ppg6 (pseudomonas oleovorans) alkane hydroxylase: monoterminal oxidation of alkanes and fatty acids.pseudomonas putida ppg6 is able to utilize purified n-alkanes of six to ten carbon atoms for growth. it can also grow on the primary terminal oxidation products of these alkanes and on 1-dodecanol but not on the corresponding 2-ketones or 1,6-hexanediol, adipic acid, or pimelic acid. revertible point mutants can be isolated which have simultaneously lost the ability to grow on all five n-alkane growth substrates but which can still grow on octanol or nonanol. an acetate-negative mutant defective ...1975804473
phylogenetic studies of two rubredoxins from sulfate reducing bacteria.the sequences of two rubredoxins isolated from the sulfate reducing bacteria: desulfovibrio vulgaris and desulfovibrio gigas have been elucidated. they have similar sequences but many more differences occur than would be expected from two bacteria of the same genus. of the 52 sites, only 37 are occupied by identical residues. the primary structures are compared with those of the anaerobic bacteria rubredoxins of clostridium pasteurianum, micrococcus aerogenes, pseudomonas oleovorans and peptostr ...1977864718
characterization of the omega-hydroxylase of pseudomonas oleovorans as a nonheme iron protein. 1977921275
enzymatic epoxidation: synthesis of 7,8-epoxy-1-octene, 1,2-7,8-diepoxyoctane, and 1,2-epoxyoctane by pseudomonas oleovorans.the kinetics of the enzymatic formation of 7,8-epoxy-1-octene, 1,2-7,8-diepoxyoctane, and 1,2-epoxyoctane by growing and resting cell suspensions of pseudomonas oleovorans are described. formation of 1,2-epoxyoctane occurs concurrently with exponential growth on 1-octene, providing that 1-octene is in excess. conversion of 1,7-octadiene to 7,8-epoxy-1-octene by cells growing on octane lags behind exponential growth and continues into the stationary phase, terminating upon cell death. formation o ...1976942210
stereoselective formation of diepoxides by an enzyme system of pseudomonas oleovorans. 1976993502
[new strain of methylotrophic bacteria pseudomonas oleovorans--a polysaccharide producer].a new strain of facultative-methylotrophic bacteria was isolated and identified as pseudomonas oleovorans. the culture grew on the methanol-containing medium (up to 6%). in addition to methanol, bacterial growth was provided by different organic acids, multicarbon alcohols and carbohydrates. during growth bacteria synthesized extracellular polysaccharide (up to 400 mg/ml). the compound included glucose, galactose and xylose.19761026940
bioconversions of aliphatic compounds by pseudomonas oleovorans in multiphase bioreactors: background and economic potential.pseudomonas oleovorans can grow on linear alkanes and alkenes in the hexane to dodecane range by virtue of enzymes encoded by the alk genes. by introducing selected alk genes into pseudomonas strains and by supplying alkanes in the growth medium as a bulk liquid phase, specific alkane oxidation products can be accumulated in the alkane phase. we review the genetics and enzymology of the alk system and the potential of bioconversions in two-liquid-phase bioreactors, and suggest that such systems ...19901366497
bioconversion of n-octane to octanoic acid by a recombinant escherichia coli cultured in a two-liquid phase bioreactor.the alk genes from the catabolic oct plasmid of pseudomonas oleovorans, which encode the enzymes involved in the oxidation of n-alkanes to carboxylic acids, were introduced into e. coli w3110. the resulting recombinant converts n-octane in a two-liquid phase medium into the corresponding alkanoate and excretes this compound into the aqueous phase. the rate of octanoic acid production by the recombinant e. coli is equal to or better than the alkane oxidation rate of p. oleovorans, suggesting that ...19911367010
identification, cloning and sequence analysis of the poly(3-hydroxyalkanoic acid) synthase gene of the gram-positive bacterium rhodococcus ruber.the first polyhydroxyalkanoic acid (pha) synthase gene (phbcrr) of a gram-positive bacterium was cloned from a genomic library of rhodococcus ruber in the broad-host-range plasmid vector prk404. the hybrid plasmid harboring phbcrr allowed the expression of polyhydroxybutyric acid (phb) synthase activity and restored the ability of phb synthesis in a phb-negative mutant of alcaligenes eutrophus. nucleotide sequence analysis of phbcrr revealed an open reading frame of 1686 bp starting with the rar ...19921526467
effect of nitrogen limitation on long-side-chain poly-beta-hydroxyalkanoate synthesis by pseudomonas resinovorans.pseudomonas resinovorans produced poly-beta-hydroxyalkanoates (phas) when grown on hydrocarbons but not on glucose. in a chemostat culture, the pha composition was beta-hydroxybutyrate (c4)-beta-hydroxyhexanoate (c6)-beta-hydroxyoctanoate (c8)-beta-hydroxydecanoate (c10) (1:15:75:9) on octanoate and c4-c6-c8-c10 (8:62:23:7) on hexanoic acid. contrary to the reported behavior of pseudomonas oleovorans, the pha accumulation rate increased under ammonium limitation on octanoate.19921610198
production of unsaturated polyesters by pseudomonas oleovorans.pseudomonas oleovorans was grown separately on 3-hydroxy-6-octenoic acid and 3-hydroxy-7-octenoic acid as the only carbon source and under ammonium nutrient-limiting conditions to produce storage polyesters. the polyesters produced contained mainly unsaturated c8 units. small amounts of both the saturated and the unsaturated c6 units were also present, but only about 1% of the saturated 3-hydroxyoctanoate units was detected. the polyester obtained from 3-hydroxy-6-octenoic acid, which was a mixt ...19902078535
hydrocarbon monooxygenase system of pseudomonas oleovorans. 19902280708
biotransformation of substituted benzoates to the corresponding cis-diols by an engineered strain of pseudomonas oleovorans producing the tol plasmid-specified enzyme toluate-1,2-dioxygenase.the conversion of substituted benzoates into 1,2-cis-dihydroxycyclohexa-3,5-diene carboxylic acids (cis-diols) was effected by using escherichia coli and pseudomonas recombinants carrying the xylxyz genes originating from the pseudomonas putida mt-2 tol plasmid, thus producing toluate-1,2-dioxygenase. pseudomonas oleovorans gpo12 recombinants readily produced meta- and para-substituted cis-diols, but were limited in their oxidation of ortho-substituted substrates.19902306096
synthesis of poly-3-hydroxyalkanoates is a common feature of fluorescent pseudomonads.the fluorescent pseudomonads are classified as a group, one characteristic of which is that they do not accumulate poly-3-hydroxybutyrate (phb) during nutrient starvation in the presence of excess carbon source. in this paper we show that prototype strains from this subclass, such as pseudomonas aeruginosa, pseudomonas putida, and pseudomonas fluorescens, do accumulate poly-3-hydroxyalkanoates (pha) when grown on fatty acids. these phas are composed of medium-chain-length (c6 to c12) 3-hydroxy f ...19892506811
alkane utilization in pseudomonas oleovorans. structure and function of the regulatory locus alkr.the oct plasmid-localized alkbac operon encodes enzymes for alkane hydroxylation and alkanol dehydrogenation. the positively controlled expression of the operon is very efficient in both pseudomonas putida and escherichia coli. two regulatory functions have been ascribed to the regulatory locus alkr: inducer recognition and transcriptional activation of the operon. we have cloned and localized the alkr locus on a 4.9-kilobase pair sali fragment. the alkr region was analyzed for translation produ ...19882843518
on the role of superoxide in reactions catalyzed by rubredoxin of pseudomonas oleovorans. 19734148231
enzymatic omega-oxidation. 3. purification and properties of rubredoxin, a component of the omega-hydroxylation system of pseudomonas oleovorans. 19684295540
cytochrome content of two pseudomonads containing mixed-function oxidase systems.the cytochrome and nonheme iron protein content of two pseudomonads, pseudomonas oleovorans and p. putida, containing mixed function oxidase systems was examined. the mixed function oxidase system of p. oleovorans and p. putida had previously been shown to be present in cells which had been grown on hexane and camphor, respectively, as energy source. the content of protoheme was found to increase significantly when the organisms were grown on the substrates for mixed function oxidation. the nonh ...19704319837
an analysis of the electron paramagnetic resonance spectrum of pseudomonas oleovorans rubredoxin. a method for determination of the liganids of ferric iron in completely rhombic sites. 19714330058
enzymatic epoxidation. i. alkene epoxidation by the -hydroxylation system of pseudomonas oleovorans. 19724341053
enzymatic omega-oxidation. iv. purification and properties of the omega-hydroxylase of pseudomonas oleovorans. 19704395379
genetic regulation of octane dissimilation plasmid in pseudomonas.the enzymes responsible for the oxidation of n-octane to octanoic acid or beyond in pseudomonas oleovorans are octane inducible and are coded by genes borne on a transmissible extrachromosomal element. the octane to octanoate enzymes induced by octane are repressed by octanol. the chromosome also carries genes coding octanol oxidation enzymes that, in contrast, are induced by octanol, not by octane. the octane plasmid has been transferred from p. oleovorans to several other fluorescent pseudomon ...19734515610
octene epoxidation by a cold-stable alkane-oxidizing isolate of pseudomonas oleovorans.the isolation of an alkane-oxidizing strain of pseudomonas oleovorans which maintains its viability at 5 c is described. this strain epoxidates 1-octene at a rate five times that of the parent strain. the most efficient substrates for induction of the epoxidase are c(7), c(8), and c(9), although c(5) to c(12) also serve as growth substrates and inducers. the greater rate may be attributed to an enhanced general stability of the cells as opposed to a modification of the enzyme system involved.19734699216
pseudomonas oleovorans hydroxylation-epoxidation system: additional strain improvements.the isolation and characterization of a strain of pseudomonas oleovorans which epoxidates 1-octene at a rate nine times that of the original strain are described. in addition, it has been confirmed that a greater amount of the mono-epoxide product is formed from 1,7-octadiene than is formed from 1-octene. 1,7-octadiene will not support growth, but will induce the enzymes required for epoxidation.19734743875
identification of the omega-hydroxylase of pseudomonas oleovorans as a nonheme iron protein requiring phospholipid for catalytic activity. 19744830742
stereoselective epoxidation of octadiene catalyzed by an enzyme system of pseudomonas oleovorans. 19744854399
metabolism of pyrimidine nucleotides in a microorganism. 3. enzymatic production of ribose-5-phosphate from uridine-5'-monophosphate by pseudomonas oleovorans.a study was made to develop a new method for the production of ribose-5-phosphate (r-5-p) from uridine-5'-monophosphate (ump) by the action of nucleotide-n-ribosidase of pseudomonas oleovorans, and a suitable medium for the formation of nucleotide-n-ribosidase was established. for the enzymatic conversion of ump to r-5-p, a cell suspension was employed as the enzyme source. although degradation of r-5-p, the desired product, occurred during the course of the enzyme reaction, it was prevented by ...19715137581
a critical analysis of kinetic data of 3-hexulosephosphate synthases. michaelis-menten or complex characteristics.investigations of the 3-hexulosephosphate synthase (hps) from different methylotrophic bacteria have revealed apparent discrepancies in kinetic behaviour. in all methanol-utilizing species investigated by us the kinetic characteristics showed intermediary plateau regions. therefore, this behaviour is assumed to be a general feature of the hps from all non-methane-utilizing methylotrophic bacteria. however, this assumption is in contrast to the results of other authors. both for methylomonas m15 ...19806775423
[regulation of citrate synthase in facultative methylotrophic bacteria].commonly the tca cycle fulfils an anabolic and a catabolic function in case of aerobic chemoorganoheterotrophic nutrition. in methylotrophic growth the tca cycle is dispensable as a bioenergetic pathway. this is reflected by properties of citrate synthase in facultative methylotrophic bacteria. two citrate synthases, a "chemoorganoheterotrophic" one, which is inhibited by nadh (or atp in acetobacter mb 58), and a "methylotrophic" one, which is not or less affected by energy indicators, were foun ...19836880250
genetics of alkane oxidation by pseudomonas oleovorans.many pseudomonads are able to use linear alkanes as sole carbon and energy source. the genetics and enzymology of alkane metabolism have been investigated in depth for pseudomonas oleovorans, which is able to oxidize c5-c12 n-alkanes by virtue of two gene regions, localized on the oct-plasmid. the so-called alk-genes have been cloned in plafr1, and were subsequent analyzed using minicell expression experiments, dna sequencing and deletion analysis. this has led to the identification and characte ...19947532480
dissociation and interaction of individual components of a degradative plasmid aggregate in pseudomonas.the transfer of the oct plasmid from pseudomonas oleovorans to pseudomonas putida strain ppgl results in the acquisition of three independent replicons: oct, factor k, and the mer plasmid. oct is a nontransmissible plasmid harboring genes that code for the enzymes responsible for the degradation of n-octane. factor k is a transfer plasmid capable of mobilizing oct as well as chromosomal genes but incapable of enhancing transfer frequencies of other transmissible plasmids such as cam, sal, or rp- ...19744530312
cloning and sequencing of a 36-kb region of the bacillus subtilis genome between the gnt and iol operons.within the framework of an international project for the sequencing of the entire bacillus subtilis genome, a 36-kb chromosome segment, which covers the region between the gnt and iol operons, has been cloned and sequenced. this region (36447 bp) contains 33 complete open reading frames (orfs; genes) including the four gnt genes and one partial gene. a homology search for the products of the 33 complete orfs revealed significant homology to known proteins in 16 of them such as tetracycline resis ...19957584049
enzymatic epoxidation. ii. comparison between the epoxidation and hydroxylation reactions catalyzed by the -hydroxylation system of pseudomonas oleovorans. 19734348547
two genes encoding proteins with similarities to rubredoxin and rubredoxin reductase are required for conversion of dodecane to lauric acid in acinetobacter calcoaceticus adp1.mutants of acinetobacter calcoaceticus adp1 unable to grow on dodecane, but retaining the ability to grow on lauric acid were isolated after ethylmethanesulphonate (ems) treatment. this growth deficiency was complemented by a clone from a gene library constructed from chromosomal dna of the wild-type strain. the complementing dna mapped in a gene encoding a polypeptide with homology to rubredoxins. the deduced putative rubredoxin amino acid sequence is more similar to related proteins from gram- ...19957670642
quantitative determination of intracellular depolymerase activity in pseudomonas oleovorans inclusions containing poly-3-hydroxyalkanoates with long alkyl substituents.research regarding the accurate, quantitative degradation of novel poly-3-hydroxyalkanoates has been restricted by the absence of an appropriate monitoring technique. the calibration of a gas chromatograph to poly-3-hydroxyoctanoate reveals a linear relationship between the area under gas chromatograph tracings and polymer weight. with this new method, poly-3-hydroxy-octanoate granules isolated from pseudomonas oleovorans, which were incubated at 30 degrees c in an alkaline buffer, exhibited a l ...19947794414
epoxidation of 1,7-octadiene by pseudomonas oleovorans: fermentation in the presence of cyclohexane.a very efficient conversion of 1,7-octadiene to 7,8-epoxy-1-octene and 1,2-7,8-diepoxyoctane was achieved by incorporating a high concentration of cyclohexane into the conventional fermentation medium. in the presence of cyclohexane, a 90-ml% conversion of substrate to product was accomplished within 72 h, compared with an 18,5-mol% conversion in the absence of cyclohexane. furthermore, the products were simultaneously separated and concentrated in the organic phase.1977889327
preparation and properties of immobilized rubredoxin.rubredoxin, one of the three protein components of the epoxidation/hydroxylation system of pseudomonas oleovorans was immobilized by attachment to cnbr-activated agarose (sepharose 4b). since this represents the first reported example of the preparation of a water-insoluble derivative of an enzyme of this type, the electron transfer and physical properties of the conjugate were examined in order to allow comparison with those of the soluble enzyme. immobilized rubredoxin exhibits all of the majo ...1977849934
assessment of the biodegradation potential of psychrotrophic microorganisms.bioremediation of polluted temperate and cold temperature environments may require the activity of psychrotrophic bacteria, because their low temperature growth range parallels the ambient temperatures encountered in these environments. in the present study, 135 psychrotrophic microorganisms isolated from a variety of ecosystems in canada were examined for their ability to mineralize 14c-labelled toluene, naphthalene, dodecane, hexadecane, 2-chlorobiphenyl, and pentachlorophenol. a number of the ...19968742353
[purification and properties of 3-hexulosephosphate synthase from facultative methylotroph pseudomonas oleovorans].3-hexulosephosphate synthase (hps), the key enzyme of the hexulosephosphate cycle of formaldehyde fixation, was isolated from facultative methylotroph pseudomonas oleovorans. enzyme was purified 100-fold. the purification procedure involved fractionation with ammonium sulfate, gel-filtration on sephadex g-150 and chromatography on deae-sephadex a-50. the purified enzyme gave single band on analytical polyacrylamide gel electrophoresis. optimal conditions for activity of hps are: ph 7,0, temperat ...1978656502
[methanol metabolism by pseudomonas oleovorans].a typical facultative methylotroph pseudomonas oleovorans oxidizes methanol to formaldehyde by a specific dehydrogenase which is active towards phenazine metosulphate. direct oxidation of formalydehyde to co2 via formiate is a minor pathway because the activities of dehydrogenases of formaldehyde and formiate are lwo. most formaldehyde molecules are involved in the hexulose phosphate cycle, which is confirmed by a high activity of hexulose phosphate synthase. formaldehyde is oxidized to co2 in t ...1977560617
rubredoxin/rubredoxin reductase of pseudomonas oleovorans: a model system for investigating interprotein electron transfer. 19968878991
kinetic properties of the purified 3-hexulosephosphate synthase from pseudomonas oleovorans.the kinetic characteristics of the purified 3-hexulosephosphate synthase from the facultative methylotroph pseudomonas oleovorans were investigated. it could be demonstrated that the dependence of the reaction rate on the rib(ul)ose-5-phosphate as well as the formaldehyde concentration has a complex shape with the appearence of plateau and trough regions. the shape of the curve is changed in dependence on the fixed level of the second substrate. multiple forms of the 3-hexulosephosphate synthase ...1979538957
controlled and functional expression of the pseudomonas oleovorans alkane utilizing system in pseudomonas putida and escherichia coli.the oct plasmid encodes enzymes for alkane hydroxylation and alkanol dehydrogenation. structural components are encoded on the 7.5-kilobase pair alkbac operon, whereas positive regulatory components are encoded by alkr. we have constructed plasmids containing fusions of cloned alkbac and alkr dna and used these fusion plasmids to study the functional expression of the alkbac operon and the regulatory locus alkr in pseudomonas putida and in escherichia coli. growth on alkanes requires a functiona ...19872826430
the pseudomonas oleovorans alkbac operon encodes two structurally related rubredoxins and an aldehyde dehydrogenase.the pseudomonas oleovorans alkbac operon encodes seven proteins, of which at least three are involved in alkane hydroxylase (alkba) and alkanol dehydrogenase (alkc) activities. we have determined the nucleotide sequence of the 2.5-kilobase pair alka region and analyzed the role of its translation products in alkane oxidation. the alka region contains three coding sequences, encoding two related rubredoxins (alkf and alkg) of 14- and 18-kda molecular mass and a 52-kda aldehyde dehydrogenase (alkh ...19892647719
effects of protein calorie malnutrition on tuberculosis in mice.infectious diseases and malnutrition represent major burdens afflicting millions of people in developing countries. both conditions affect individuals in industrialized nations, particularly the aged, the hiv-infected, and people with chronic diseases. while malnutrition is known to induce a state of immunodeficiency, the mechanisms responsible for compromised antimicrobial resistance in malnourished hosts remain obscure. in the present study, mice fed a 2% protein diet and developing protein ca ...19968962145
the pseudomonas oleovorans alkane hydroxylase gene. sequence and expression.we have identified and sequenced the pseudomonas oct plasmid-encoded alkane hydroxylase gene (alkb) and its promoter. the transcription initiation site of the alkbac mrna was determined by nuclease s1 mapping. a putative interaction site with rna-polymerase was identified based on homology of the alk promoter with other pseudomonas promoters. the alkb gene encodes a 401-amino acid polypeptide which, despite an unusual codon composition, can be expressed at high levels in escherichia coli and pse ...19892647718
metabolism of poly(3-hydroxyalkanoates) (phas) by pseudomonas oleovorans. identification and sequences of genes and function of the encoded proteins in the synthesis and degradation of pha.pseudomonas oleovorans accumulates poly(3-hydroxyalkanoates) (phas) after growth on medium chain length hydrocarbons. large amounts of this polyester are synthesized when cells are grown under nitrogen-limiting conditions. when nitrogen is resupplied in the medium, the accumulated pha is degraded. in this paper, we describe mutants which are defective in the synthesis or in the degradation of pha. these mutants were used to select dna fragments which encode pha polymerases and a pha depolymerase ...19911989978
biosynthesis and characterization of hydroxybutyrate-hydroxycaproate copolymers.most polyhydroxyalkanoates (phas) reported to date fall into one of two broad classes: either hydroxybutyrate-hydroxyvalerate copolymers (typified by the pha produced by alcaligenes eutrophus), or hydroxyoctanoate-rich heteropolymers (typified by the pha produced by pseudomonas oleovorans). few reports of copolymers rich in hydroxybutyrate (hb), but containing a minor proportion of a co-monomer with a higher carbon number than valerate, have appeared. here we report on the biosynthesis and chara ...19957547720
oxidation of 1-alkenes to 1,2-epoxyalkanes by pseudomonas oleovorans.resting cells of pseudomonas oleovorans po-1r that had been grown on octane oxidized 1-alkenes containing 6 to 12 carbon atoms and 1,7-octadiene to their corresponding 1,2-epoxides. the microorganism was capable of growing on 1-octene but not on 1,7-octadiene as a sole carbon source. the optimal temperature, ph, and 1-octene concentration for 1,2-epoxyoctane production by the resting cells were 34 to 40 c, ph 7 to 8, and 1.5 mg of 1-octene per ml, respectively. epoxide concentration reached a ma ...19734726833
structural effects on the reactivity of substrates and inhibitors in the epoxidation system of pseudomonas oleovorans.the epoxidation reaction catalyzed by an enzyme system of pseudomonas oleovorans exhibits a substrate specificity different from that expected on the basis of chemical reactivity in non-enzymatic epoxidation reactions. cyclic and internal olefins, aromatic compounds and styrene are not epoxidated. the reactivity of straight chain diolefins is maximal for octadiene and falls off rapidly as the carbon chain is shortened, but decreases only slightly as the chain is lengthened. in contrast, methyl g ...19751174548
development and characterization of a whole-cell bioluminescent sensor for bioavailable middle-chain alkanes in contaminated groundwater samples.a microbial whole-cell biosensor was developed, and its potential to measure water-dissolved concentrations of middle-chain-length alkanes and some related compounds by bioluminescence was characterized. the biosensor strain escherichia coli dh5 alpha(pgec74, pjama7) carried the regulatory gene alks from pseudomonas oleovorans and a transcriptional fusion of palkb from the same strain with the promoterless luciferase luxab genes from vibrio harveyi on two separately introduced plasmids. in stand ...19979327569
recombinant two-iron rubredoxin of pseudomonas oleovorans: overexpression, purification and characterization by optical, cd and 113cd nmr spectroscopies.the gene (alk g) encoding the two-iron rubredoxin of pseudomonas oleovorans was amplified from genomic dna by pcr and subcloned into the expression vector pkk223-3. the vector directed the high-level production of rubredoxin in escherichia coli. a simple three-step procedure was used to purify recombinant rubredoxin in the 1fe form. 1fe-rubredoxin was readily converted to the 2fe, apoprotein and cadmium forms after precipitation with trichloroacetic acid and resolubilization in the presence or a ...19979359843
dna sequence determination and functional characterization of the oct-plasmid-encoded alkjkl genes of pseudomonas oleovorans.the alkbfghjkl and alkst operons encode enzymes that allow pseudomonas putida (oleovorans) to metabolize alkanes. in this paper we report the nucleotide sequence of a 4592 bp region of the alkbfghjkl operon encoding the alkj, alkk and alkl polypeptides. the alkj gene encodes a protein of 59 kilodaltons. the predicted amino acid sequence shows significant homology with four flavin proteins: choline dehydrogenase, a glucose dehydrogenase and two oxidases. alkj is membrane-bound and converts alipha ...19921453953
expression and characterization of (r)-specific enoyl coenzyme a hydratase involved in polyhydroxyalkanoate biosynthesis by aeromonas caviae.complementation analysis of a polyhydroxyalkanoate (pha)-negative mutant of aeromonas caviae proved that orf3 in the pha locus (a 402-bp gene located downstream of the pha synthase gene) participates in pha biosynthesis on alkanoic acids, and the orf3 gene is here referred to as phaj(ac). escherichia coli bl21(de3) carrying phaj(ac). under the control of the t7 promoter overexpressed enoyl coenzyme a (enoyl-coa) hydratase, which was purified by one-step anion-exchange chromatography. the n-termi ...19989457873
alkane hydroxylase from acinetobacter sp. strain adp1 is encoded by alkm and belongs to a new family of bacterial integral-membrane hydrocarbon hydroxylases.degradation of long-chain alkanes by acinetobacter sp. strain adp1 involves rubredoxin and rubredoxin reductase. we complemented a mutant deficient in alkane utilization and sequenced four open reading frames (orfs) on the complementing dna. each of these orfs was disrupted by insertional mutagenesis on the chromosome. as determined from sequence comparisons, orf1 and orf4 seem to encode a rotamase of the ppic type and an acyl coenzyme a dehydrogenase, respectively. disruption of these orfs does ...19989546151
a gene cluster encoding steps in conversion of naphthalene to gentisate in pseudomonas sp. strain u2.pseudomonas sp. strain u2 was isolated from oil-contaminated soil in venezuela by selective enrichment on naphthalene as the sole carbon source. the genes for naphthalene dioxygenase were cloned from the plasmid dna of strain u2 on an 8.3-kb bamhi fragment. the genes for the naphthalene dioxygenase genes nagaa (for ferredoxin reductase), nagab (for ferredoxin), and nagac and nagad (for the large and small subunits of dioxygenase, respectively) were located by southern hybridizations and by nucle ...19989573207
towards a biocatalyst for (s)-styrene oxide production: characterization of the styrene degradation pathway of pseudomonas sp. strain vlb120.in order to design a biocatalyst for the production of optically pure styrene oxide, an important building block in organic synthesis, the metabolic pathway and molecular biology of styrene degradation in pseudomonas sp. strain vlb120 was investigated. a 5.7-kb xhoi fragment, which contained on the same strand of dna six genes involved in styrene degradation, was isolated from a gene library of this organism in escherichia coli by screening for indigo formation. t7 rna polymerase expression expe ...19989603811
efflux pumps involved in toluene tolerance in pseudomonas putida dot-t1e.the basic mechanisms underlying solvent tolerance in pseudomonas putida dot-t1e are efflux pumps that remove the solvent from bacterial cell membranes. the solvent-tolerant p. putida dot-t1e grows in the presence of high concentrations (e.g., 1% [vol/vol]) of toluene and octanol. growth of p. putida dot-t1e cells in lb in the presence of toluene supplied via the gas phase has a clear effect on cell survival: the sudden addition of 0.3% (vol/vol) toluene to p. putida dot-t1e pregrown with toluene ...19989642183
biodegradation of variable-chain-length alkanes at low temperatures by a psychrotrophic rhodococcus sp.the psychorotrophic rhodococcus sp. strain q15 was examined for its ability to degrade individual n-alkanes and diesel fuel at low temperatures, and its alkane catabolic pathway was investigated by biochemical and genetic techniques. at 0 and 5 degrees c, q15 mineralized the short-chain alkanes dodecane and hexadecane to a greater extent than that observed for the long-chain alkanes octacosane and dotriacontane. q15 utilized a broad range of aliphatics (c10 to c21 alkanes, branched alkanes, and ...19989647833
oxygen activating nonheme iron enzymes.the past year has witnessed significant advances in the study of oxygen-activating nonheme iron enzymes. thirteen crystal structures of substrate and substrate analog complexes of protocatechuate 3, 4-dioxygenase have revealed intimate details about changes at the enzyme active site during catalysis. crystallographic data have established a 2-his-1-carboxylate facial triad as a structural motif common to a number of mononuclear nonheme iron enzymes, including isopenicillin n synthase, tyrosine h ...19989667935
bacterial polyesters containing branched poly(beta-hydroxyalkanoate) units.pseudomonas oleovorans was grown on mixtures of methyloctanoates with n-octanoate. polymers were also obtained from organisms grown on pure 7-methyloctanoate, but not from pure 5- or 6-methyloctanoate. the polyesters obtained from 7-methyloctanoate and from its mixtures with n-octanoate contained units with the methyl branches in the pendant group, as did the copolymers from the mixtures of 5- and 6-methyloctanoate with n-octanoate. the methyl branched repeating units contained two diastereomers ...19902078536
the regulated outer membrane protein omp21 from comamonas acidovorans is identified as a member of a new family of eight-stranded beta-sheet proteins by its sequence and properties.omp21, a minor outer membrane protein of the soil bacterium comamonas acidovorans, was purified from a spontaneous mutant lacking a surface layer and long-chain lipopolysaccharide. omp21 synthesis is enhanced by oxygen depletion, and the protein has a variable electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis due to its heat-modifiable behavior. the structural gene omp21 encodes a precursor of 204 amino acids with a putative signal peptide of 21 amino acids. m ...19989683466
purification and characterization of the coniferyl aldehyde dehydrogenase from pseudomonas sp. strain hr199 and molecular characterization of the gene.the coniferyl aldehyde dehydrogenase (caldh) of pseudomonas sp. strain hr199 (dsm7063), which catalyzes the nad+-dependent oxidation of coniferyl aldehyde to ferulic acid and which is induced during growth with eugenol as the carbon source, was purified and characterized. the native protein exhibited an apparent molecular mass of 86,000 +/- 5,000 da, and the subunit mass was 49.5 +/- 2.5 kda, indicating an alpha2 structure of the native enzyme. the optimal oxidation of coniferyl aldehyde to feru ...19989721273
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
topology of the membrane-bound alkane hydroxylase of pseudomonas oleovorans.the pseudomonas oleovorans alkane hydroxylase is an integral cytoplasmic membrane protein that is expressed and active in both escherichia coli and p. oleovorans. its primary sequence contains eight hydrophobic stretches that could span the membrane as alpha-helices. the topology of alkane hydroxylase was studied in e. coli using protein fusions linking different amino-terminal fragments of the alkane hydroxylase (alkb) to alkaline phosphatase (phoa) and to beta-galactosidase (lacz). four alkb-p ...19921315749
a new metabolic link between fatty acid de novo synthesis and polyhydroxyalkanoic acid synthesis. the phag gene from pseudomonas putida kt2440 encodes a 3-hydroxyacyl-acyl carrier protein-coenzyme a transferase.to investigate the metabolic link between fatty acid de novo synthesis and polyhydroxyalkanoic acid (pha) synthesis, we isolated mutants of pseudomonas putida kt2440 deficient in this metabolic route. the gene phag was cloned by phenotypic complementation of these mutants; it encoded a protein of 295 amino acids with a molecular mass of 33,876 da, and the amino acid sequence exhibited 44% amino acid identity to the primary structure of the rhla gene product, which is involved in the rhamnolipid ...19989727022
carbon-source-dependent expression of the palkb promoter from the pseudomonas oleovorans alkane degradation pathway.pseudomonas oleovorans gpo1 can metabolize medium-chain-length alkanes by means of an enzymatic system whose induction is regulated by the alks protein. in the presence of alkanes, alks activates the expression of promoter palkb, from which most of the genes of the pathway are transcribed. in addition, expression of the first enzyme of the pathway, alkane hydroxylase, is known to be influenced by the carbon source present in the growth medium, indicating the existence of an additional overimpose ...19989748457
[purification and properties of glucose-6-phosphate and 6-phosphogluconate dehydrogenases from pseudomonas oleovorans].the glucose-6-phosphate and 6-phosphogluconate dehydrogenases i. e. enzymes of dissimilatory hexulose phosphate cycle, were isolated from the cells of the facultative methylotrophic bacterium pseudomonas oleovorans. the purification procedure included protein fractionation by ammonium sulfate, gel-filtration through sephacryl s-200 and chromatography on deae bio-gel a and phosphocellulose, resulting in a 400-fold purification of the enzyme. during analytical disc-electrophoresis in polyacrylamid ...19807236789
molecular characterization of an n-alkane-degrading bacterial community and identification of a new species, acinetobacter venetianus.twenty-five bacterial strains isolated from the venice lagoon and implicated in the degradation of n-alkanes, n-alkanols, n-alkanals and n-alkanoates were characterized in molecular and physiological terms. the isolates were grouped by amplified ribosomal dna restriction analysis (ardra) into seven clusters, corresponding to seven species, six of which were identified on the basis of 16s rdna sequencing. genetic variability among strains was shown by random amplified polymorphic dna (rapd). only ...19979765804
a novel heat-stable lipolytic enzyme from sulfolobus acidocaldarius dsm 639 displaying similarity to polyhydroxyalkanoate depolymerases.a fragment of genomic dna from sulfolobus acidocaldarius dsm 639 encoding a lipolytic enzyme was cloned and sequenced. the 314-amino acid polypeptide displays a maximum sequence similarity (43%) to a putative polyhydroxyalkanoate depolymerase from pseudomonas oleovorans and contains the pentapeptide g-x1-s-x2-g which is typical of serine hydrolases. the protein is highly thermostable and is able to hydrolyse a variety of lipid substrates thus providing a promising tool for potential biotechnolog ...19989785454
enzymatic omega-oxidation. v. forms of pseudomonas oleovorans rubredoxin containing one or two iron atoms: structure and function in omega-hydroxylation. 19715542691
expression of alkane hydroxylase from acinetobacter sp. strain adp1 is induced by a broad range of n-alkanes and requires the transcriptional activator alkr.in acinetobacter sp. strain adp1, alkane degradation depends on at least five essential genes. rubab and xcpr are constitutively transcribed. here we describe inducible transcription of alkm, which strictly depends on the presence of the transcriptional activator alkr. alkr itself is expressed at a low level, while a chromosomally located alkm::lacz fusion is inducible by middle-chain-length alkanes from heptane to undecane, which do not support growth of adp1, and by long-chain-length alkanes f ...19989811637
the alkane oxidation system of pseudomonas oleovorans: induction of the alk genes in escherichia coli w3110 (pgec47) affects membrane biogenesis and results in overexpression of alkane hydroxylase in a distinct cytoplasmic membrane subfraction.the alkane hydroxylase system of pseudomonas oleovorans, which catalyses the initial oxidation of aliphatic substrates, is encoded by three genes. one of the gene products, the alkane hydroxylase alkb, is an integral cytoplasmic membrane protein. induction leads to the synthesis of 1.5-2% alkb relative to the total cell protein, both in p. oleovorans and in recombinant escherichia coli dh1. we present a study on the induction and localization of the alkane hydroxylase in e. coli w3110, which app ...19938361351
cloning of the alcaligenes latus polyhydroxyalkanoate biosynthesis genes and use of these genes for enhanced production of poly(3-hydroxybutyrate) in escherichia coli.polyhydroxyalkanoates (phas) are microbial polyesters that can be used as completely biodegradable polymers, but the high production cost prevents their use in a wide range of applications. recombinant escherichia coli strains harboring the ralstonia eutropha pha biosynthesis genes have been reported to have several advantages as pha producers compared with wild-type pha-producing bacteria. however, the pha productivity (amount of pha produced per unit volume per unit time) obtained with these r ...19989835580
cloning and molecular analysis of the poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyalkanoate) biosynthesis genes in pseudomonas sp. strain 61-3.two types of polyhydroxyalkanoate (pha) biosynthesis gene loci (phb and pha) of pseudomonas sp. strain 61-3, which produces a blend of poly(3-hydroxybutyrate) [p(3hb)] homopolymer and a random copolymer (poly(3-hydroxybutyrate-co-3-hydroxyalkanoate) [p(3hb-co-3ha]) consisting of 3ha units of 4 to 12 carbon atoms, were cloned and analyzed at the molecular level. in the phb locus, three open reading frames encoding polyhydroxybutyrate (phb) synthase (phbcps), beta-ketothiolase (phbaps), and nadph- ...19989851987
microbial desulfurization of a crude oil middle-distillate fraction: analysis of the extent of sulfur removal and the effect of removal on remaining sulfur.rhodococcus sp. strain ecrd-1 was evaluated for its ability to desulfurize a 232 to 343 degrees c middle-distillate (diesel range) fraction of oregon basin (ob) crude oil. ob oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. gas chromatography (gc), flame ionization detection, and gc sulfur chemiluminesce detection analysis were used to qualitatively evaluate ...19999872778
transport of octanoate by pseudomonas oleovorans.the properties of a system for octanoate transport in pseudomonas oleovarans are described. transport is inducible and energy dependent, shows saturation kinetics, and concentrates against a gradient. optimal transport is at ph 6.0 and 28 c. apparent k(m) and v(max) values are, respectively, 7.0 mum octanoate and 0.68 nmol of octanoate transported per min per mg (dry mass) of cells. fatty acids from c(7) to c(12) are competitive inhibitors, whereas alkanes, alkenes, and esters of the same carbon ...19734745429
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
phaf, a polyhydroxyalkanoate-granule-associated protein of pseudomonas oleovorans gpo1 involved in the regulatory expression system for pha genes.the phac1 gene codes for the medium-chain-length polyhydroxyalkanoate (mcl pha) synthase of pseudomonas oleovorans gpo1, which produces mcl pha when grown in an excess of carbon source and under nitrogen limitation. in this work, we have demonstrated, by constructing a recombinant p. oleovorans strain carrying a phac1::lacz reporter system, that the phac1 gene is expressed efficiently in the presence of octanoic acid while its expression is repressed when glucose or citrate is used as the carbon ...19999922249
screening, nucleotide sequence, and biochemical characterization of an esterase from pseudomonas fluorescens with high activity towards lactones.a genomic library of pseudomonas fluorescens dsm 50106 in a lambdaresiii phage vector was screened in escherichia coli k-12 for esterase activity by using alpha-naphthyl acetate and fast blue rr. a 3.2-kb dna fragment was subcloned from an esterase-positive clone and completely sequenced. esterase estf1 was encoded by a 999-bp open reading frame (orf) and exhibited significant amino acid sequence identity with members of the serine hydrolase family. the deduced amino acid sequences of two other ...19999925571
production of medium-chain-length poly(3-hydroxyalkanoates) from gluconate by recombinant escherichia coli.it was shown recently that recombinant escherichia coli, defective in the beta-oxidation cycle and harboring a medium-chain-length (mcl) poly(3-hydroxyalkanoate) (pha) polymerase-encoding gene of pseudomonas, is able to produce mcl pha from fatty acids but not from sugars or gluconate (s. langenbach, b. h. a. rehm, and a. steinbüchel, fems microbiol. lett. 150:303-309, 1997; q. ren, ph.d. thesis, eth zürich, zürich, switzerland, 1997). in this study, we report the formation of mcl pha from gluco ...19999925580
isolation and characterization of a mycobacterium species capable of degrading three- and four-ring aromatic and aliphatic hydrocarbons.mycobacterium sp. strain ch1 was isolated from polycyclic aromatic hydrocarbon (pah)-contaminated freshwater sediments and identified by analysis of 16s rdna sequences. strain ch1 was capable of mineralizing three- and four-ring pahs including phenanthrene, pyrene, and fluoranthene. in addition, strain ch1 could utilize phenanthrene or pyrene as a sole carbon and energy source. a lag phase of at least 3 days was observed during pyrene mineralization. this lag phase decreased to less than 1 day w ...19999925581
analysis of 4-phosphopantetheinylation of polyhydroxybutyrate synthase from ralstonia eutropha: generation of beta-alanine auxotrophic tn5 mutants and cloning of the pand gene region.the postulated posttranslational modification of the polyhydroxybutyrate (pha) synthase from ralstonia eutropha by 4-phosphopantetheine was investigated. four beta-alanine auxotrophic tn5-induced mutants of r. eutropha hf39 were isolated, and two insertions were mapped in an open reading frame with strong similarity to the pand gene from escherichia coli, encoding l-aspartate-1-decarboxylase (ec 4.1.1.15), whereas two other insertions were mapped in an open reading frame (orf) with strong simila ...199910049372
the palkbfghjkl promoter is under carbon catabolite repression control in pseudomonas oleovorans but not in escherichia coli alk+ recombinants.the alk genes are located on the oct plasmid of pseudomonas oleovorans and encode an inducible pathway for the utilization of n-alkanes as carbon and energy sources. we have investigated the influence of alternative carbon sources on the induction of this pathway in p. oleovorans and escherichia coli alk+ recombinants. in doing so, we confirmed earlier reports that induction of alkane hydroxylase activity in pseudomonads is subject to carbon catabolite repression. specifically, synthesis of the ...199910049394
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
role of the alternative sigma factor sigmas in expression of the alks regulator of the pseudomonas oleovorans alkane degradation pathway.the alks protein activates transcription from the palkb promoter, allowing the expression of a number of genes required for the assimilation of alkanes in pseudomonas oleovorans. we have identified the promoter from which the alks gene is transcribed, palks, and analyzed its expression under different conditions and genetic backgrounds. transcription from palks was very low during the exponential phase of growth and increased considerably when cells reached the stationary phase. the palks -10 re ...199910074066
solubilization of the overexpressed integral membrane protein alkane monooxygenase of the recombinant escherichia coli w3110[pgec47].the integral membrane-bound alkane monooxygenase (alkb) from pseudomonas oleovorans has been overexpressed in the recombinant escherichia coli strain w3110[pgec47] and expression levels of 10 to 15% relative to the total cell protein were reached. the amount of phospholipids in induced cells is about 3-fold higher compared to the wild-type and alkb has been shown to be located in small membrane vesicles. we present here a study on the solubilization of these alkb containing membrane vesicles by ...19947841178
determinants for overproduction of the pseudomonas oleovorans cytoplasmic membrane protein alkane hydroxylase in alk+ escherichia coli w3110.the pseudomonas oleovorans alkb gene is expressed in alk+ escherichia coli w3110 to 10 to 15% of the total cell protein, which is exceptional for a (foreign) cytoplasmic membrane protein. in other e. coli recombinants such as alk+ hb101, alkb constitutes 2 to 3% of the total protein. in this study, we have investigated which factors determine the expression level of alkb in alk+ w3110. in particular, we have investigated the role of alkb-induced stimulation of phospholipid synthesis. blocking ph ...19979006031
reduction of cell lysate viscosity during processing of poly(3-hydroxyalkanoates) by chromosomal integration of the staphylococcal nuclease gene in pseudomonas putida.poly(3-hydroxyalkanoates) (phas) are biodegradable thermoplastics which are accumulated by many bacterial species in the form of intracellular granules and which are thought to serve as reserves of carbon and energy. pseudomonas putida accumulates a polyester, composed of medium-side-chain 3-hydroxyalkanoic acids, which has excellent film-forming properties. industrial processing of pha involves purification of the pha granules from high-cell-density cultures. after the fermentation process, cel ...199910103246
nahw, a novel, inducible salicylate hydroxylase involved in mineralization of naphthalene by pseudomonas stutzeri an10.two genes, nahg and nahw, encoding two independent salicylate 1-hydroxylases have been identified in the naphthalene-degrading strain pseudomonas stutzeri an10. while nahg resides in the same transcriptional unit as the meta-cleavage pathway genes, forming the naphthalene degradation lower pathway, nahw is situated outside but in close proximity to this transcriptional unit. the nahg and nahw genes of p. stutzeri an10 are induced and expressed upon incubation with salicylate, and the enzymes tha ...199910197990
a novel aromatic-ring-hydroxylating dioxygenase from the diterpenoid-degrading bacterium pseudomonas abietaniphila bkme-9.pseudomonas abietaniphila bkme-9 is able to degrade dehydroabietic acid (dha) via ring hydroxylation by a novel dioxygenase. the dita1, dita2, and dita3 genes, which encode the alpha and beta subunits of the oxygenase and the ferredoxin of the diterpenoid dioxygenase, respectively, were isolated and sequenced. the ferredoxin gene is 9. 2 kb upstream of the oxygenase genes and 872 bp upstream of a putative meta ring cleavage dioxygenase gene, ditc. a tn5 insertion in the alpha subunit gene, dita1 ...199910217753
adhesion of acinetobacter venetianus to diesel fuel droplets studied with in situ electrochemical and molecular probesthe adhesion of a recently described species, acinetobacter venetianus ve-c3 (f. di cello, m. pepi, f. baldi, and r. fani, res. microbiol. 148:237-249, 1997), to diesel fuel (a mixture of c12 to c28 n-alkanes) and n-hexadecane was studied and compared to that of acinetobacter sp. strain rag-1, which is known to excrete the emulsifying lipopolysaccharide, emulsan. oxygen consumption rates, biomass, cell hydrophobicity, electrophoretic mobility, and zeta potential were measured for the two strains ...199910223998
isolation and characterization of the cis-trans-unsaturated fatty acid isomerase of pseudomonas oleovorans gpo12.pseudomonas oleovorans contains an isomerase which catalyzes the cis-trans conversion of the abundant unsaturated membrane fatty acids 9-cis-hexadecenoic acid (palmitoleic acid) and 11-cis-octadecenoic acid (vaccenic acid). we purified the isomerase from the periplasmic fraction of pseudomonas oleovorans. the molecular mass of the enzyme was estimated to be 80 kda under denaturing conditions and 70 kda under native conditions, suggesting a monomeric structure of the active enzyme. n-terminal seq ...199910322030
an alkane-responsive expression system for the production of fine chemicalsmembrane-located monooxygenase systems, such as the pseudomonas putida mt-2-derived xylene oxygenase, are attractive for challenging transformations of apolar compounds, including enantiospecific epoxidations, but are difficult to synthesize at levels that are useful for application to biotechnological processes. in order to construct efficient biocatalysis strains, we utilized the alkane-responsive regulatory system of the oct plasmid-located alk genes of pseudomonas oleovorans gpo1, a very att ...199910347009
type 2 nadh dehydrogenases in the cyanobacterium synechocystis sp. strain pcc 6803 are involved in regulation rather than respiration.analysis of the genome of synechocystis sp. strain pcc 6803 reveals three open reading frames (slr0851, slr1743, and sll1484) that may code for type 2 nad(p)h dehydrogenases (ndh-2). the sequence similarity between the translated open reading frames and ndh-2s from other organisms is low, generally not exceeding 30% identity. however, nad(p)h and flavin adenine dinucleotide binding motifs are conserved in all three putative ndh-2s in synechocystis sp. strain pcc 6803. the three open reading fram ...199910383967
physiological adaptations involved in alkane assimilation at a low temperature by rhodococcus sp. strain q15.we examined physiological adaptations which allow the psychrotroph rhodococcus sp. strain q15 to assimilate alkanes at a low temperature (alkanes are contaminants which are generally insoluble and/or solid at low temperatures). during growth at 5 degrees c on hexadecane or diesel fuel, strain q15 produced a cell surface-associated biosurfactant(s) and, compared to glucose-acetate-grown cells, exhibited increased cell surface hydrophobicity. a transmission electron microscopy examination of strai ...199910388690
isolation and characterization of a sulfate-reducing bacterium that anaerobically degrades alkanes.an alkane-degrading, sulfate-reducing bacterial strain, ak-01, was isolated from an estuarine sediment with a history of chronic petroleum contamination. the bacterium is a short, nonmotile, non-spore-forming, gram-negative rod. it is mesophilic and grows optimally at ph 6.9 to 7.0 and at an nacl concentration of 1%. formate, fatty acids (c4 to c16) and hydrogen were readily utilized as electron donors. sulfate, sulfite, and thiosulfate were used as electron acceptors, but sulfur, nitrite, and n ...199910388691
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