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localization and mapping of co2 fixation genes within two gene clusters in rhodobacter sphaeroides.two fructose 1,6-bisphosphatase structural genes (fbpa and fbpb) have been identified within two unlinked gene clusters that were previously shown to contain the rhodobacter sphaeroides sequences that code for form i and form ii ribulose 1,5-bisphosphate carboxylase-oxygenase and phosphoribulokinase. the fbpa and fbpb genes were localized to a region immediately upstream from the corresponding prka and prkb sequences and were found to be transcribed in the same direction as the phosphoribulokina ...19882834328
the kinetics of glucose-fructose oxidoreductase from zymomonas mobilis.glucose-fructose oxidoreductase operates by a classic ping-pong mechanism with a single site for all substrates: glucose, fructose, gluconolactone and sorbitol. the km values for these substrates were determined. the values of kcat are 200 s-1 and 0.8 s-1 for the forward and reverse directions respectively. the overall catalytic process consists of two half-reactions with alternate reduction of nadp+ and oxidation of nadph tightly bound to the enzyme. reduction of enzyme-nadp+ by glucose and oxi ...19883356190
expression of different levels of ethanologenic enzymes from zymomonas mobilis in recombinant strains of escherichia coli.the expression of zymomonas mobilis genes encoding pyruvate decarboxylase and alcohol dehydrogenase ii in escherichia coli converted this organism from the production of organic acids to the production of ethanol. ethanol was produced during both anaerobic and aerobic growth. the extent to which these ethanologenic enzymes were expressed correlated with the extent of ethanol production. the replacement of organic acids with ethanol as a metabolic product during aerobic and anaerobic growth resul ...198816347553
effect of intraparticle diffusion in ethanol fermentation by immobilized zymomonas mobilis. 198818584650
liquid residence time distributions in immobilized cell bioreactors.previous work has demonstrated that high ethanol productivities can be achieved using yeast or bacterial cells adsorbed onto the surface of ion exchange resin in vertical packed bed bioreactors. the present work quantitatively characterizes the overall degree of backmixing in such reactors at two scales of operation: 2.0 and 8.0 l. stimulus-response experiments, using two solvents (2,3-butanediol and 2-ethoxyethanol) as tracers, were performed to measure the liquid phase residence time distribut ...198918587958
growth inhibition of zymomonas mobilis atcc 10988 by ammonium ions. 198918588103
cloning, sequencing, and characterization of the principal acid phosphatase, the phoc+ product, from zymomonas mobilis.the zymomonas mobilis gene encoding acid phosphatase, phoc, has been cloned and sequenced. the gene spans 792 base pairs and encodes an mr 28,988 polypeptide. this protein was identified as the principal acid phosphatase activity in z. mobilis by using zymograms and was more active with magnesium ions than with zinc ions. its promoter region was similar to the -35 "pho box" region of the escherichia coli pho genes as well as the regulatory sequences for saccharomyces cerevisiae acid phosphatase ...19892914872
prokaryotic triterpenoids. a novel hopanoid from the ethanol-producing bacterium zymomonas mobilis.among the triterpenoids of the bacterium zymomonas mobilis a novel hopanoid, 32-oxobacteriohopane-33,34,35-triol beta-linked via its primary hydroxy group to glucosamine, has been isolated as a minor compound.19892640564
pyruvate decarboxylase is like acetolactate synthase (ilv2) and not like the pyruvate dehydrogenase e1 subunit.protein sequences of pyruvate decarboxylase (pdc) derived from cloned yeast (saccharomyces cerevisiae) and bacterial (zymomonas mobilis) genes were compared with each other and with sequence databases. extensive sequence similarities were found between them and with two others: cytochrome-linked pyruvate oxidase from escherichia coli and acetolactate synthase (ilvi in e. coli; ilv2 gene in s. cerevisiae). all catalyse decarboxylation of pyruvate using thiamine pyrophosphate (tpp) as cofactor. ge ...19892651151
transposable elements for efficient manipulation of a wide range of gram-negative bacteria: promoter probes and vectors for foreign genes.we describe here the construction and use of a series of modified transposons based on the insertion sequence is1. like their parent, omegon-km [fellay et al., gene 76 (1989) 215-226], these elements permit efficient insertional mutagenesis of a variety of gram-negative bacteria. the presence of a functional pbr322 origin of replication within the transposable element facilitates subsequent cloning of the mutated gene. the omegon-km system was previously shown to function in pseudomonas putida, ...19892559879
the stereospecificity of the ferrous-ion-dependent alcohol dehydrogenase from zymomonas mobilis.alcohol dehydrogenase from zymomonas mobilis has been found to transfer the pro-r hydrogen of nadh to acetaldehyde. this is the first report of the stereospecificity of a dehydrogenase in the mechanistic and structural class of fe2+-dependent alcohol dehydrogenases and offers an opportunity to expand mechanistic hypotheses relating stereospecificity, reaction mechanism and reaction thermodynamics in dehydrogenases.19892924772
modulation of alcohol dehydrogenase isoenzyme levels in zymomonas mobilis by iron and zinc.zymomonas mobilis is an unusual microorganism which utilizes both iron-containing alcohol dehydrogenase (adhii) and zinc-containing alcohol dehydrogenase (adhi) isoenzymes during fermentative growth. this organism is obligately ethanologenic, and alcohol dehydrogenase activity is essential. the activities of adhi and adhii were altered by supplementing growth medium with iron or zinc salts and by iron starvation. growth under iron-limiting conditions (chelators, minimal medium) reduced adhii act ...19892914864
similarity of escherichia coli propanediol oxidoreductase (fuco product) and an unusual alcohol dehydrogenase from zymomonas mobilis and saccharomyces cerevisiae.the gene that encodes 1,2-propanediol oxidoreductase (fuco) from escherichia coli was sequenced. the reading frame specified a protein of 383 amino acids (including the n-terminal methionine), with an aggregate molecular weight of 40,642. the induction of fuco transcription, which occurred in the presence of fucose, was confirmed by northern blot analysis. in e. coli, the primary fuco transcript was approximately 2.1 kilobases in length. the 5' end of the transcript began more than 0.7 kilobase ...19892661535
molecular analysis and nucleotide sequence of the adh1 gene encoding an nadph-dependent butanol dehydrogenase in the gram-positive anaerobe clostridium acetobutylicum.the nucleotide sequence of a 2081-bp fragment of clostridium acetobutylicum dna containing the adh1 gene was determined. the butanol dehydrogenase gene is referred to as the adh1 gene since it was shown to have activity using butanol and ethanol as substrates. the adh1 gene consisted of 1164 bp and encoded an alcohol dehydrogenase (adh) enzyme of 388 aa residues with an mr of 43,274. the adh1 gene was separated from an upstream open reading frame by an intergenic region of 354 bp. no promoter co ...19892673928
efficient ethanol production from glucose, lactose, and xylose by recombinant escherichia coli.lactose and all of the major sugars (glucose, xylose, arabinose, galactose, and mannose) present in cellulose and hemicellulose were converted to ethanol by recombinant escherichia coli containing plasmid-borne genes encoding the enzymes for the ethanol pathway from zymomonas mobilis. environmental tolerances, plasmid stability, expression of z. mobilis pyruvate decarboxylase, substrate range, and ethanol production (from glucose, lactose, and xylose) were compared among eight american type cult ...19892675762
differential expression of gap and pgk genes within the gap operon of zymomonas mobilis.in zymomonas mobilis, the genes encoding glyceraldehyde-3-phosphate dehydrogenase (gap) and phosphoglycerate kinase (pgk) are encoded in an operon that is transcribed from tandem promoters. the promoter-proximal gap gene is expressed at six- to ninefold higher levels than the pgk gene from chromosomal genes and from multiple copies of plasmid-borne genes. two dominant transcripts were identified. the smaller, most abundant transcript contained primarily the gap message, whereas the larger, less ...19892687242
[cloning the pyruvate decarboxylase gene of zymomonas mobilis and its expression in escherichia coli].the pyruvate decarboxylase gene of zymomonas mobilis cp4 has been cloned in escherichia coli strain tg1 cells on the puc18 vector plasmid. activity of the enzyme in the lysates of the obtained clones is about 30 units per 1 mg of protein. neither the dependence of the pyruvate decarboxylase activity on the presence of iptg or glucose in the cultivation medium nor the difference in activity of the enzyme for the clones harbouring the recombinant plasmids with the different orientation of the pyru ...19892693955
expression of zymomonas mobilis adhb (encoding alcohol dehydrogenase ii) and adhb-lacz operon fusions in recombinant z. mobilis.the zymomonas mobilis alcohol dehydrogenase ii gene (adhb) was overexpressed 7- to 14-fold on a recombinant plasmid, accompanied by a small decrease in growth rate. a fragment containing the truncated gene with promoter reduced expression from the chromosomal gene as measured immunologically and enzymatically, consistent with the presence of a trans-active regulatory factor and positive regulatory control. both the complete gene and the promoter fragment increased pyruvate decarboxylase and gluc ...19892504692
behavior of the hybrid plasmid pnsw301 in zymomonas mobilis grown in continuous culture.the stability of the plasmid pnsw301 which was formed by cointegration of the inc w r plasmid sa and the 14.5-kb pnsw1 plasmid of zymomonas mobilis zm6100 was investigated in zm6100(pnsw301) grown in continuous culture without antibiotic selection. the cointegrate plasmid, pnsw301, was found to be structurally unstable and a total reduction in the size of pnsw301 of approximately 21 kb occurred during growth in continuous culture. following a systematic study, a number of deletion derivatives of ...19902217571
determination of hopanoid levels in bacteria using high-performance liquid chromatography.a reverse-phase hplc method to detect and quantify levels of hopanoids in bacteria has been developed. chromophores have been introduced by derivatization and the levels of the c35 hopanoids and their conjugates can be measured in bacterial lipid extracts down to picomole levels. some structural variations of the complex lipids were detected after derivatization and were easily purified using the same hplc system. zymomonas mobilis and rhodospirillum rubrum extracts were examined using this syst ...19902109551
cloning of the zymomonas mobilis structural gene encoding alcohol dehydrogenase i (adha): sequence comparison and expression in escherichia coli.zymomonas mobilis ferments sugars to produce ethanol with two biochemically distinct isoenzymes of alcohol dehydrogenase. the adha gene encoding alcohol dehydrogenase i has now been sequenced and compared with the adhb gene, which encodes the second isoenzyme. the deduced amino acid sequences for these gene products exhibited no apparent homology. alcohol dehydrogenase i contained 337 amino acids, with a subunit molecular weight of 36,096. based on comparisons of primary amino acid sequences, th ...19902185223
sequence and genetic organization of a zymomonas mobilis gene cluster that encodes several enzymes of glucose metabolism.the zymomonas mobilis genes that encode glucose-6-phosphate dehydrogenase (zwf), 6-phosphogluconate dehydratase (edd), and glucokinase (glk) were cloned independently by genetic complementation of specific defects in escherichia coli metabolism. the identity of these cloned genes was confirmed by various biochemical means. nucleotide sequence analysis established that these three genes are clustered on the genome and revealed an additional open reading frame in this region that has significant a ...19902254282
analysis and stability of zymomonas mobilis atcc 10988 plasmid pzmo3.plasmid pzmo3 of zymomonas mobilis strain atcc 10988 was found to be nonhomologous either to chromosomal dna or to any other plasmids of the strains atcc 10988, ncib 11163, and cp4. it contained single sites for the restriction endonucleases sphi, bgli, and hindiii, as well as at least four sites for sau3a. its origin of replication is located within the 1.54-kb sau3a fragment as it was found that only the recombinant plasmid pds3154, which contained this fragment, showed vectorial incompatibili ...19902349282
construction of expression vectors for the gram-negative bacterium zymomonas mobilis.a set of vectors was constructed for the cloning and expression of heterologous genes in the gram-negative bacterium zymomonas mobilis under the control of the pdc promoter of z. mobilis. the vectors pptz1, pptz3, and pptz4 are based on the cryptic z. mobilis plasmid pzm02 and on parts of the escherichia coli plasmids pkk223-3 and pbr322 together with the multiple cloning site of phage m13mp18. dna fragments can be readily inserted immediately downstream from the pdc promoter at unique restricti ...19902250658
cloning and sequencing of the saca gene: characterization of a sucrase from zymomonas mobilis.the zymomonas mobilis gene (saca) encoding a protein with sucrase activity has been cloned in escherichia coli and its nucleotide sequence has been determined. potential ribosome-binding site and promoter sequences were identified in the region upstream of the gene which were homologous to e. coli and z. mobilis consensus sequences. extracts from e. coli cells, containing the saca gene, displayed a sucrose-hydrolyzing activity. however, no transfructosylation activity (exchange reaction or levan ...19902254250
activation of the lac genes of tn951 by insertion sequences from pseudomonas cepacia.we have identified three transposable gene-activating elements from pseudomonas cepacia on the basis of their abilities to increase expression of the lac genes of the broad-host-range plasmid pgc91.14 (prp1::tn951). when introduced into auxotrophic derivatives of p. cepacia 249 (atcc 17616), this plasmid failed to confer the ability to utilize lactose. the lac genes of tn951 were poorly expressed in p. cepacia and were not induced by isopropyl-beta-d-thiogalactopyranoside. lac+ variants of the p ...19902156800
inactivation of pyruvate decarboxylase by 3-hydroxypyruvate.pyruvate decarboxylase from zymomonas mobilis is inhibited by 3-hydroxypyruvate, which can also act as a poor substrate. while catalysing the decarboxylation of this alternative substrate, the enzyme undergoes a progressive but partial inactivation over several hours. the extent of inactivation depends upon the ph and upon the concentration of 3-hydroxypyruvate. after partial inactivation and removal of unchanged 3-hydroxypyruvate, enzymic activity recovers slowly. we suggest that inactivation r ...19902310379
differential salt-promoted chromatography for protein purification.a range of hydrophobic-type adsorbents for protein chromatography has been screened for the binding, at high salt concentrations, of 10 enzymes from a bacterial extract. adsorbents were chosen for tandem chromatography, in which the first adsorbent removed much of the protein, and the second and subsequent columns bound the desired enzymes. simple schemes for isolating zymomonas mobilis and yeast alcohol dehydrogenases are described, in which the enzymes are affinity eluted by nad+.19901368158
nucleotide sequence of the zymomonas mobilis alcohol dehydrogenase ii gene. 19902308827
immobilized cell biocatalyst activation and pseudo-steady-state behavior: model and experiment.an intrinsic, unstructured model has been utilized to describethe startup dynamics of a continuous caalginate-immobilized zymomonas mobilis (atcc 10988) fermentation. this model predicts, at least qualitatively, transients in the fermenter effluent glucose, ethanol, and biomass concentrations as well as radial gradients in immobilized-cell concentration and activity within the gelbiocatalysts. predicted intrabiocatalyst gradients in immobilized-cell specific growth rate were used to calculate th ...199018592556
a structured kinetic model for zymomonas mobilis atcc10988.the inhibitory effects of glucose and ethanol on zymomonas mobilis atcc10988 were isolated through kinetic analysis of transient batch fermentation data. growth of z. mobilis was inhibited above a glucose concentration of 80 g/l. growth was mildly inhibited by ethanol to 50 g/l, and severely inhibited above this concentration. specific rates of ethanol production and glucose uptake were essentially invariant during batch fermentation. a structured kinetic model was developed, by way of augmentat ...199018597261
a new biosensor for specific determination of glucose or fructose using an oxidoreductase of zymomonas mobilis.cells of zymomonas mobilis were permeabilized with toluene in order to utilize the enzymes, glucose-fructose oxidoreductase and gluconolactonase, inside the intact cells. permeabilized cells were immobilized in a gelatin membrane, and a whole cell enzyme electrode was constructed by fixing the membrane on ph electrode. the biosensor developed was used for specific determination of glucose or fructose by detecting the production rate of hydrogen ion. optimum conditions for biosensor response were ...199018597267
genetic modification of zymomonas mobilis.the bacterium zymomonas mobilis is a potentially useful organism for the commercial production of ethanol as it is capable of more than double the rate of alcohol production by yeast. however, industrial application of this bacterium has been restricted in part due to the disadvantages of its limited substrate range (glucose, fructose and sucrose) and by-product formation. progress in strain improvement and genetic manipulation of this ethanologen is reviewed. methodologies for gaining reproduci ...199014549608
a new biosensor for specific determination of sucrose using an oxidoreductase of zymomonas mobilis and invertase.a new biosensor for specific determination of sucrose was developed using an oxidoreductase of zymomonas mobilis and invertase. cells of z. mobilis were permeabilized with toluene in order to utilize the enzymes of glucose-fructose oxidoreductase and gluconolactonase inside the intact cells. permeabilized cells and invertase were coimmobilized in a gelatin membrane, and a whole cell enzyme electrode was constructed by fixing the membrane on a ph electrode. the production of hydrogen ion was dete ...199118600754
tubular bioreactors: case study of bioreactor performance for industrial production and scientific research.application of bioreactors is dominated by industrial production with the consequence that bioreactors also for scientific purposes are mainly used following an empiric pragmatic approach. for the sake of a breakthrough in biotechnology in general, and especially for advanced process development, a more systematic approach is emphasized here. this methodology in bioreactor performance studies is explained and the meaning clarified in a case study of a new type of tubular bioreactor. the central ...199118597337
cloning and expression in escherichia coli of mercuric ion resistance coding genes from zymomonas mobilis.from a genomic library of zymomonas mobilis prepared in escherichia coli, two clones (carrying pzh4 and pzh5) resistant to the mercuric ion were isolated. on partial restriction analysis these two clones appeared to have the same 2.9 kb insert. mercuric reductase activity was assayed from the escherichia coli clone carrying pzh5 and it was hg(2+)-inducible, nadh dependent and also required 2-mercaptoethanol for its activity. the plasmid pzh5 encoded three polypeptides, mercuric reductase (mera; ...19911367242
ethanol production by recombinant escherichia coli carrying genes from zymomonas mobilis.efficient utilization of lignocellulosic feedstocks offers an opportunity to reduce the cost of producing fuel ethanol. the fermentation performance characteristics of recombinant escherichia coli atcc 11303 carrying the "pet plasmid" (ploi297) with the lac operon controlling the expression of pyruvate decarboxylase (pdc) and alcohol dehydrogenase ii (adhb) genes cloned from zymomonas mobilis cp4 (alterthum & ingram, 1989) were assessed in batch and continuous processes with sugar mixtures desig ...19911929364
electron microscopic analysis and biochemical characterization of a novel methanol dehydrogenase from the thermotolerant bacillus sp. c1.methanol dehydrogenase from the thermotolerant bacillus sp. c1 was studied by electron microscopy and image processing. two main projections can be distinguished: one exhibits 5-fold symmetry and has a diameter of 15 nm, the other is rectangular with sides of 15 and 9 nm. subsequent image processing showed that the 5-fold view possesses mirror symmetry. the rectangular views can be divided into two separate classes, one of which has 2-fold rotational symmetry. it is concluded that methanol dehyd ...19911995642
production of beta-carotene in zymomonas mobilis and agrobacterium tumefaciens by introduction of the biosynthesis genes from erwinia uredovora.the erwinia uredovora crtb, crte, crti, and crty genes required for beta-carotene biosynthesis were introduced by conjugal transfer into an ethanol-producing bacterium, zymomonas mobilis, and a phytopathogenic bacterium, agrobacterium tumefaciens, in which no carotenoid is synthesized. the transconjugants of z. mobilis and a. tumefaciens carrying these genes appeared as yellow colonies and produced 220 and 350 micrograms of beta-carotene per g of dry weight, respectively, in the stationary phase ...19911872613
content and composition of hopanoids in zymomonas mobilis under various growth conditions.by using a new method for quantification of the different hopanoid derivatives, a total hopanoid content of about 30 mg/g (dry cell weight) was observed in zymomonas mobilis. this value is the highest reported for bacteria so far. the major hopanoids in z. mobilis were the ether and glycosidic derivatives of tetrahydroxy-bacteriohopane, constituting about 41 and 49% of the total hopanoids. tetrahydroxybacteriohopane itself, diplopterol, and hopene made up about 6, 3, and 1%, respectively. only m ...19911885538
cloning, characterization, and nucleotide sequence analysis of a zymomonas mobilis phosphoglucose isomerase gene that is subject to carbon source-dependent regulation.the zymomonas mobilis gene encoding phosphoglucose isomerase (pgi) was cloned by genetic complementation of an escherichia coli pgi mutant. an enzyme assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis confirmed the presence of excess amounts of phosphoglucose isomerase in e. coli clones carrying the z. mobilis pgi gene. the pgi gene is present in only one copy on the z. mobilis genome. nucleotide sequence analysis of the pgi region revealed an open reading frame of 1,524 bp prec ...19911708765
segmental message stabilization as a mechanism for differential expression from the zymomonas mobilis gap operon.in zymomonas mobilis, three- to fourfold more glyceraldehyde-3-phosphate dehydrogenase protein than phosphoglycerate kinase is needed for glycolysis because of differences in catalytic efficiency. consistent with this requirement, higher levels of glyceraldehyde-3-phosphate dehydrogenase were observed with two-dimensional polyacrylamide gel electrophoresis. the genes encoding these enzymes (gap and pgk, respectively) form a bicistronic operon, and some form of regulation is required to provide t ...19911702780
metabolic engineering of klebsiella oxytoca m5a1 for ethanol production from xylose and glucose.the efficient diversion of pyruvate from normal fermentative pathways to ethanol production in klebsiella oxytoca m5a1 requires the expression of zymomonas mobilis genes encoding both pyruvate decarboxylase and alcohol dehydrogenase. final ethanol concentrations obtained with the best recombinant, strain m5a1 (ploi555), were in excess of 40 g/liter with an efficiency of 0.48 g of ethanol (xylose) and 0.50 g of ethanol (glucose) per g of sugar, as compared with a theoretical maximum of 0.51 g of ...19911746941
cloning, characterization and expression of the zymononas mobilis eda gene that encodes 2-keto-3-deoxy-6-phosphogluconate aldolase of the entner-doudoroff pathway.the eda gene that encodes 2-keto-3-deoxy-6-phosphogluconate aldolase of the entner-doudoroff pathway was cloned from zymomonas mobilis by genetic complementation of an escherichia coli mutant. the gene is present in a single copy on the z. mobilis genome and is not tightly linked to the edd gene. nucleotide sequence analysis of the eda region revealed that the structural gene is 627 bp long and capable of encoding a protein of 208 amino acids with a deduced molecular weight of 21,505. the eda ge ...19911809834
cloning, sequencing, and characterization of the intracellular invertase gene from zymomonas mobilis.the structural gene for the intracellular invertase e1 of zymomonas mobilis strain z6c was cloned in a 2.25-kb dna fragment on push11, and expressed in escherichia coli hb101. the enzyme produced by the e. coli carrying push11 was purified about 1,122 fold to homogenicity with a yield of 4%. the molecular weight and substrate specificity of the enzyme were identical with those of the intracellular invertase e1 from z. mobilis. the nucleotides of the cloned dna were sequenced; they included an op ...19911368686
the use of multifunctional adsorbents to purify membrane-bound phosphatases from zymomonas mobilis. purification of acid phosphatase, alkaline phosphatase and atpase.the purification of detergent-solubilized membrane-bound phosphatases from zymomonas mobilis using novel adsorbents is described. the prepared adsorbents have a hydrophobic core with functional groups attached. these functional groups may either increase or decrease the hydrophobicity of the adsorbent, or participate in other forms of interactions. adsorption of acid phosphatase (acp), alkaline phosphatase (alp) and atpase to these adsorbents was salt-promoted. desorption was achieved by decreas ...19911368773
membrane-associated atpase from zymomonas mobilis; purification and characterization.the major atpase (adenosinetriphosphatase, ec 3.6.1.3) activity present in the membrane of zymomonas mobilis has been isolated, using a novel combination of multifunctional hydrophobic adsorbents. on subjecting the preparation to gel filtration, activity was lost, but could be restored by reconstituting fractions from the column. subunit composition of the fractions indicated that the zymomonas mobilis atpase is of the f0f1 type, and so is probably involved in proton pumping. the contribution of ...19911832963
genetic improvement of escherichia coli for ethanol production: chromosomal integration of zymomonas mobilis genes encoding pyruvate decarboxylase and alcohol dehydrogenase ii.zymomonas mobilis genes for pyruvate decarboxylase (pdc) and alcohol dehydrogenase ii (adhb) were integrated into the escherichia coli chromosome within or near the pyruvate formate-lyase gene (pfl). integration improved the stability of the z. mobilis genes in e. coli, but further selection was required to increase expression. spontaneous mutants were selected for resistance to high level of chloramphenicol that also expressed high levels of the z. mobilis genes. analogous mutants were selected ...19912059047
expression of an l-alanine dehydrogenase gene in zymomonas mobilis and excretion of l-alanine.an approach to broaden the product range of the ethanologenic, gram-negative bacterium zymomonas mobilis by means of genetic engineering is presented. gene alad for l-alanine dehydrogenase (ec 1.4.1.1.) from bacillus sphaericus was cloned and introduced into z. mobilis. under the control of the strong promoter of the pyruvate decarboxylase (pdc) gene, the enzyme was expressed up to a specific activity of nearly 1 mu mol . min -1 . mg of protein -1 in recombinant cells. as a results of this high ...19911854197
gel electrophoretic analysis of zymomonas mobilis glycolytic and fermentative enzymes: identification of alcohol dehydrogenase ii as a stress protein.the 13 major enzymes which compose the glycolytic and fermentative pathways in zymomonas mobilis are particularly abundant and represent one-half of the soluble protein in exponential-phase cells. one- and two-dimensional polyacrylamide gel electrophoresis maps were developed for 12 of these enzymes. assignments were made by comigration with purified proteins, comparison with overexpressed genes in recombinant strains, and western blots (immunoblots). although most glycolytic enzymes appeared re ...19911917831
molecular cloning of the gene for indolepyruvate decarboxylase from enterobacter cloacae.although indole-3-acetic acid (iaa) is a well-known plant hormone, the main iaa biosynthetic pathway from l-tryptophan (trp) via indole-3-pyruvic acid (ipya) has yet to be elucidated. previous studies have suggested that iaa is produced by enterobacter cloacae isolated from the rhizosphere of cucumbers and its biosynthetic pathway may possibly be the same as that in plants. to elucidate this pathway, the iaa biosynthetic gene was isolated from a genomic library of e. cloacae by assaying for the ...19912034209
pyruvate decarboxylase from zymomonas mobilis. structure and re-activation of apoenzyme by the cofactors thiamin diphosphate and magnesium ion.to study the mechanism of re-activation of zymomonas mobilis pyruvate decarboxylase apoenzyme by its cofactors thiamin diphosphate and mg2+, cofactor-free enzyme was prepared by dialysis against 1 mm-dipicolinic acid at ph 8.2. this apoenzyme was then used in a series of experiments that included determination of: (a) the affinity towards one cofactor when the other was present at saturating concentrations; (b) cofactor-binding rates by measuring the quenching of tryptophan fluorescence on the a ...19912049073
batch fermentation kinetics of sugar beet molasses by zymomonas mobilis.a new osmotolerant mutant strain of zymomonas mobilis was successfully used for ethanol production from beet molasses. addition of magnesium sulfate to hydrolyzed molasses allowed repeated growth without the need of yeast extract addition. the kinetics and yields parameters of fermentation on media with different molasses concentrations were calculated. the anabolic parameters (specific growth rate, mu, and biomass yield, y(x/s)) were inhibited at elevated molasses concentrations while the catab ...199118600764
effect of alteration of the acetic acid synthesis pathway on the fermentation pattern of escherichia coli.the glucose metabolism of an escherichia coli strain bearing mutations abolishing both acetyl phosphotransferase (pta) and acetate kinase (ack) activities was studied under aerobic and anaerobic conditions. these studies were conducted in a complex medium with the mutant carrying no plasmid, the mutant carrying the common cloning vector puc19, and the mutant carrying a plasmid bearing the "pet" operon that encodes zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase activities. the ...199118600733
continuous production of gluconic acid and sorbitol from jerusalem artichoke and glucose using an oxidoreductase of zymomonas mobilis and inulinase.gluconic acid and sorbitol were simultaneously produced from glucose and jerusalem artichoke using a glucose-fructose oxidoreductase of zymomonas mobilis and inulinase. inulinase was immobilized on chitin by cross-linking with glutaraldehyde. cells of z. mobilis permeabilized with toluene were coimmobilized with chitin-immobilized inulinase in alginate beads. the optimum amounts of both chitin-immobilized inulinase and permeabilized cells for coimmobilization were determined, and operational con ...199218600950
effects of substitution of aspartate-440 and tryptophan-487 in the thiamin diphosphate binding region of pyruvate decarboxylase from zymomonas mobilis.a tryptophan residue at position 487 in zymomonas mobilis pyruvate decarboxylase was altered to leucine by site-directed mutagenesis. this modified z. mobilis pyruvate decarboxylase was active when expressed in escherichia coli and had unchanged kinetics towards pyruvate. the enzyme showed a decreased affinity for the cofactors with the half-saturating concentrations increasing from 0.64 to 9.0 microm for thiamin diphosphate and from 4.21 to 45 microm for mg2+. unlike the wild-type enzyme, there ...19921730299
the entner-doudoroff pathway: history, physiology and molecular biology.the entner-doudoroff pathway is now known to be very widely distributed in nature. biochemical and physiological studies show that the entner-doudoroff pathway can operate in a linear and catabolic mode, in a 'cyclic' mode, in a modified mode involving non-phosphorylated intermediates, or in alternative modes involving c1 metabolism and anabolism. molecular and genetic analyses of the entner-doudoroff pathway in zymomonas mobilis, escherichia coli and pseudomonas aeruginosa have led to an improv ...19921389313
isolation and characterization of the gene encoding gluconolactonase from zymomonas mobilis.the gene encoding the enzyme gluconolactonase (d-glucono-delta-lactone lactonohydrolase, ec 3.1.1.17) has been isolated from a recombinant library of genomic zymomonas mobilis dna, by detection of enzyme activity in recombinant clones. the gene encoded a protein of 320 amino acids, which is processed to the mature enzyme of 285 amino acids (31079 da) by cleavage at an ala-ala bond, as determined from n-terminal sequencing of the purified enzyme. a minor sequence commencing at amino acid 6 is sug ...19921482681
characterization of zymomonas mobilis alkaline phosphatase activity in escherichia coli.zymomonas mobilis phoa gene encoding alkaline phosphatase was expressed in escherichia coli cc118 carrying the recombinant plasmid pzap1. the ph optimum for this enzyme was 9.0 and showed a peak activity at 42 degrees c. this enzyme required zn2+ for its catalytic activity; however, mg2+ or ca2+ significantly affected the activity. this enzyme was found to be ethanolabile, and ethanol inhibition was reversed by addition of zn2+. kinetics of z. mobilis alkaline phosphatase production in e. coli c ...19921369189
cloning and expression in escherichia coli of a phoa gene encoding a phosphate-irrepressible alkaline phosphatase of zymomonas mobilis.the zymomonas mobilis phoa gene, encoding a phosphate-irrepressible alkaline phosphatase (zapase), was cloned and its expression was studied in phoa mutants of escherichia coli. the zapase was recovered in the soluble fraction of e. coli. the enzyme was synthesized constitutively and its synthesis not repressed by phosphate, unlike the phoa gene of e. coli. the phoa gene of z. mobilis was mutagenized by mini mu pr13 and the mutated gene crossed into z. mobilis in order to obtain phoa mutants by ...19921459397
broad host range plasmids carrying the escherichia coli lactose and galactose operons.we have developed a number of broad-host-range plasmids that allow the expression of the escherichia coli lac operon from any cloned promoter, and the creation of 'in phase' fusions between lacz and other cloned genes. in a second series of constructions, the e. coli gal operon has been cloned into the broad-host-range vector and a plasmid carrying both the e. coli gal and lac genes is described. these plasmids have been transferred into pseudomonas aeruginosa and zymomonas mobilis and their eff ...19921526459
cloning, sequence analysis, and expression of the structural gene encoding glucose-fructose oxidoreductase from zymomonas mobilis.the gene encoding glucose-fructose oxidoreductase (gfo) from zymomonas mobilis was cloned in escherichia coli and sequenced. an open reading frame of 439 amino acids encoded a protein of 49 kda. a leader sequence of 52 amino acids preceded the n-terminal sequence of the enzyme, indicating cleavage of the precursor protein at an ala-ala site to give rise to an active form of the enzyme of 43 kda. processing of the glucose-fructose oxidoreductase leader sequence, although not complete, was demonst ...19921537789
purification and characterization of pyruvate decarboxylase from sarcina ventriculi.pyruvate decarboxylase from the obligate anaerobe sarcina ventriculi was purified eightfold. the subunit mr was 57,000 +/- 3000 as estimated from sds-page, and the native mr estimated by gel filtration on a superose 6 column was 240,000, indicating that the enzyme is a tetramer. the mr values are comparable to those for pyruvate decarboxylase from zymomonas mobilis and saccharomyces cerevisiae, which are also tetrameric enzymes. the enzyme was oxygen stable, and had a ph optimum within the range ...19921588311
molecular characterization of the entner-doudoroff pathway in escherichia coli: sequence analysis and localization of promoters for the edd-eda operon.the nucleotide sequence of the entire escherichia coli edd-eda region that encodes the enzymes of the entner-doudoroff pathway was determined. the edd structural gene begins 236 bases downstream of zwf. the eda structural gene begins 34 bases downstream of edd. the edd reading frame is 1,809 bases long and encodes the 602-amino-acid, 64,446-da protein 6-phosphogluconate dehydratase. the deduced primary amino acid sequences of the e. coli and zymomonas mobilis dehydratase enzymes are highly conse ...19921624451
ethanol production from cellobiose, amorphous cellulose, and crystalline cellulose by recombinant klebsiella oxytoca containing chromosomally integrated zymomonas mobilis genes for ethanol production and plasmids expressing thermostable cellulase genes from clostridium thermocellum.the zymomonas mobilis genes for ethanol production have been integrated into the chromosome of klebsiella oxytoca m5a1. the best of these constructs, strain p2, produced ethanol efficiently from cellobiose in addition to monomeric sugars. utilization of cellobiose and cellotriose by this strain eliminated the requirement for external beta-glucosidase and reduced the amount of commercial cellulase needed to ferment solka floc sw40 (primarily crystalline cellulose). the addition of plasmids encodi ...19921637151
artificial neural networks in bioprocess state estimation.the application of artificial neural networks to the estimation and prediction of bioprocess variables is presented in this paper. a neural network methodology is discussed, which uses environmental and physiological information available from on-line sensors, to estimate concentration of species in the bioreactor. two case studies are presented, both based on the ethanol production by zymomonas mobilis. an efficient optimization algorithm which reduces the number of iterations required for conv ...19921636477
inhibition of transketolase and pyruvate decarboxylase by omeprazole.omeprazole inhibited two thiamin diphosphate-dependent enzymes, pyruvate decarboxylase (ec 4.1.1.1, pdc) from zymomonas mobilis and transketolase (ec 2.2.1.1, tk) from human erythrocytes. inhibition of pdc was competitive with the coenzyme with a ki value of 42 +/- 3 microm, whereas inhibition of tk was complex.19921632833
effect of acetic acid on xylose conversion to ethanol by genetically engineered e. coli.efficient utilization of the pentosan fraction of hemicellulose from lignocellulosic feedstocks offers an opportunity to increase the yield and to reduce the cost of producing fuel ethanol. during prehydrolysis (acid hydrolysis or autohydrolysis of hemicellulose), acetic acid is formed as a consequence of the deacetylation of the acetylated moiety of hemicellulose. recombinant escherichia coli b (atcc 11303), carrying the plasmid plo1297 with pyruvate decarboxylase and alcohol dehydrogenase ii g ...19921622203
cloning and characterization of a gene from bacillus stearothermophilus var. non-diastaticus encoding a glycerol dehydrogenase.a 4.1-kb ecori fragment which includes the gene (glda) encoding a glycerol dehydrogenase (g1dh; ec 1.1.1.6; glycerol:nad oxidoreductase) from bacillus stearothermophilus var. non-diastaticus has been cloned by virtue of its ability to restore glycerol utilisation to escherichia coli glycerol kinase (glpk) and glycerol-3-phosphate dehydrogenase (glpd) mutants. sequencing suggests that the glda gene is likely to be monocistronic and encodes a protein of 39450 da. the deduced amino acid composition ...19921339360
purification and primary structure of pyruvate decarboxylase from zymomonas mobilis.pyruvate decarboxylase (e.c. 4.1.1.1), the key enzyme in the glycolytic pathway to ethanol, was isolated in gram amounts from zymomonas mobilis for structural studies. the primary structure was determined by automated edman degradation and compared with that deduced from the dna sequence of the structural gene, previously published by two groups (a. d. neale, r. k. scopes, r. e. h. wettenhall, and n. j. hoogenraad, 1987, nucleic acids res. 15, 1753-1761; m. reynen, and h. sahm, 1988, j. bacterio ...19921586459
changes in the fluorescence of bound nucleotide during the reaction catalysed by glucose-fructose oxidoreductase from zymomonas mobilis.the reduction of gluconolactone by glucose-fructose oxidoreductase containing tightly bound nadph (enzyme-nadph) is biphasic in nucleotide fluorescence. the initial rapid decrease, which represents quenching of the fluorescence by bound lactone, is followed by a slower decrease which corresponds to the change in absorbance. at low glucose concentrations, the oxidation of glucose by enzyme-nadp+ involves a single first-order process with similar rate constants in fluorescence and absorbance. at h ...19921572370
the polycistronic mrna of the zymomonas mobilis glf-zwf-edd-glk operon is subject to complex transcript processing.the full-length 6.14-kb polycistronic glf-zwf-edd-glk mrna from zymomonas mobilis appears to be processed by endonucleolytic cleavage, resulting in the formation of several discrete transcripts. northern analysis and transcript mapping revealed that the processed transcripts correspond to functional mono-, di-, or tricistronic messages. the relative abundance of the gene-specific, functional messages was measured. expression of zwf and edd correlated well with functional message levels. dispropo ...19921569014
the zymomonas mobilis glf, zwf, edd, and glk genes form an operon: localization of the promoter and identification of a conserved sequence in the regulatory region.the zymomonas mobilis genes that encode the glucose-facilitated diffusion transporter (glf), glucose-6-phosphate dehydrogenase (zwf), 6-phosphogluconate dehydratase (edd), and glucokinase (glk) are clustered on the genome. the data presented here firmly establish that the glf, zwf, edd, and glk genes form an operon, in that order. the four genes of the operon are cotranscribed on a 6.14-kb mrna. the site of transcriptional initiation for the polycistronic message was mapped by primer extension a ...19921569013
molecular characterization of the zymomonas mobilis enolase (eno) gene.the zymomonas mobilis gene encoding enolase was cloned by genetic complementation of an escherichia coli eno mutant. an enzyme assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis confirmed the overexpression of enolase in e. coli clones carrying the z. mobilis eno gene. the eno gene is present in a single copy of the z. mobilis genome. nucleotide sequence analysis of the eno region revealed an open reading frame of 1,293 bp that encodes a protein of 428 amino acids with a predict ...19921400207
coordination of expression of zymomonas mobilis glycolytic and fermentative enzymes: a simple hypothesis based on mrna stability.although zymomonas mobilis is prototrophic, glycolytic and fermentative enzymes (ethanologenic enzymes) constitute over half of the cytoplasmic protein. in this study, transcript stability, functional message pools, and the abundance of cytoplasmic products were compared for genes encoding eight of these essential enzymes. the transcripts of all were very stable, with half-lives ranging from 8 to 18 min. this transcript stability is proposed as an important feature in z. mobilis that may disting ...19921400196
mechanism of glutamate uptake in zymomonas mobilis.the energetics of the anaerobic gram-negative bacterium zymomonas mobilis, a well-known ethanol-producing organism, is based solely on synthesis of 1 mol of atp per mol of glucose by the entner-doudoroff pathway. when grown in the presence of glucose as a carbon and energy source, z. mobilis had a cytosolic atp content of 3.5 to 4 mm. because of effective ph homeostasis, the components of the proton motive force strongly depended on the external ph. at ph 5.5, i.e., around the optimal ph for gro ...19921332937
immunocytochemical localization of glycolytic and fermentative enzymes in zymomonas mobilis.gold-labeled antibodies were used to examine the subcellular locations of 11 glycolytic and fermentative enzymes in zymomonas mobilis. glucose-fructose oxidoreductase was clearly localized in the periplasmic region. phosphogluconate lactonase and alcohol dehydrogenase i were concentrated in the cytoplasm near the plasma membrane. the eight remaining enzymes were more evenly distributed within the cytoplasmic matrix. selected enzyme pairs were labeled on opposite sides of the same thin section to ...19921320611
effective diffusivity of galactose in calcium alginate gels containing immobilized zymomonas mobilis.the effective diffusivity of galactose was measured for calcium alginate gel membranes containing immobilized live zymomonas mobilis cells at concentrations ranging from 0 to 150 g dry wt/l of gel. since galactose is not taken up by living z. mobilis organisms, the diffusion of this representative six-carbon sugar could be studied independently of sugar consumption. various immobilized biomass loadings were achieved by two different techniques: addition of biomass at known concentrations to the ...19921368005
cloning and expression in escherichia coli of an alkaline phosphatase (phoa) gene from zymomonas mobilis.an alkaline phosphatase (phoa) gene from zymomonas mobilis was isolated in escherichia coli cc118 by use of the plasmid bluescript ks+. the origin of the 6.4-kb dna fragment in pzap1 from the chromosome of z. mobilis was confirmed by southern blotting and hybridization studies. the z. mobilis phoa gene was localized at one end of the chromosomal insert on plasmid pzap1. the z. mobilis phoa gene was expressed from its own promoter in e. coli, and the enzyme was localized to the periplasmic space. ...19921369200
cloning and molecular characterization of the dna ligase gene (lig) from zymomonas mobilis.the zymomonas mobilis lig gene that encodes dna ligase was cloned from a cosmid library and identified by genetic complementation of a conditional-lethal escherichia coli dna ligase mutant. nucleotide sequence analysis of the z. mobilis lig region indicated that the gene is 2196 bp long, encoding a protein with a deduced molecular mass of 82,089. the primary amino acid sequence of the z. mobilis ligase is 48% identical to the e. coli enzyme. two genes located upstream of lig were identified as t ...19921526462
use of the tac promoter and laciq for the controlled expression of zymomonas mobilis fermentative genes in escherichia coli and zymomonas mobilis.the zymomonas mobilis genes encoding alcohol dehydrogenase i (adha), alcohol dehydrogenase ii (adhb), and pyruvate decarboxylase (pdc) were overexpressed in escherichia coli and z. mobilis by using a broad-host-range vector containing the tac promoter and the laciq repressor gene. maximal iptg (isopropyl-beta-d-thiogalactopyranoside) induction of these plasmid-borne genes in z. mobilis resulted in a 35-fold increase in alcohol dehydrogenase i activity, a 16.7-fold increase in alcohol dehydrogena ...19921429459
cloning, sequencing, and expression of the zymomonas mobilis fructokinase gene and structural comparison of the enzyme with other hexose kinases.the frk gene encoding the enzyme fructokinase (fructose 6-phosphotransferase [ec 2.7.1.4]) from zymomonas mobilis has been isolated on a partial taqi digest fragment of the genome and sequenced. an open reading frame of 906 bp corresponding to 302 amino acids was identified on a 3-kbp taqi fragment. the deduced amino acid sequence corresponds to the first 20 amino acids (including an n-terminal methionine) determined by amino acid sequencing of the purified protein. the 118 bp preceding the meth ...19921317376
fermentation of sweet whey by ethanologenic escherichia coli.whey, an abundant byproduct of the dairy industry, contains large amounts of protein and lactose which could be used for fuel ethanol production. we have investigated a new organism as a candidate for such fermentations: recombinant escherichia coli containing the genes encoding the ethanol pathway from zymomonas mobilis. the highest level of ethanol achieved, 68 g/l, was produced after 108 hours in luria broth containing 140 g lactose/l. fermentations of lower lactose concentrations were comple ...199218601042
influence of expression of the pet operon on intracellular metabolic fluxes of escherichia coli.fermentation patterns of escherichia coli hb101 carrying plasmids expressing cloned genes of zymomonas mobilis pyruvate decarboxylase (pdc) and alcohol dehydrogenase li (adh) were determined in glucose-limited complex medium in ph-controlled anaerobic batch cultivations. time profiles of glucose, dry cell weight, succinate, formate, acetate, and ethanol were determined, as were the activities of adh and pdc. fluxes through the central carbon pathways were calculated for each construct utilizing ...199218600887
transport and intracellular accumulation of acetaldehyde in saccharomyces cerevisiae.the rate of acetaldehyde efflux from yeast cells and its intracellular concentration were studied in the light of recent suggestions that acetaldehyde inhibition may be an important factor in yeast ethanol fermentations. when the medium surrounding cells containing ethanol and acetaldehyde was suddenly diluted, the rate of efflux of acetaldehyde was slow relative to the rate of ethanol efflux, suggesting that acetaldehyde, unlike ethanol, may accumulate intracellularly. intracellular acetaldehyd ...199318609643
zymomonas mobilis research in the pernambuco federal university. 19937764199
an allosterically insensitive class of cyclohexadienyl dehydrogenase from zymomonas mobilis.the key enzyme of tyrosine biosynthesis in many gram-negative prokaryotes is cyclohexadienyl dehydrogenase. the zymomonas mobilis gene (tyrc) coding for this enzyme was cloned in escherichia coli by complementation of a tyrosine auxotroph. the tyrc gene was 882 bp long, encoding a protein with a calculated molecular mass of 32086 da. the z. mobilis cyclohexadienyl dehydrogenase expressed in e. coli was purified to electrophoretic homogeneity. the subunit molecular mass of the purified enzyme was ...19937916685
isoprenoid biosynthesis in bacteria: two different pathways?the biosynthesis of isopentenylpyrophosphate, a central intermediate of isoprenoid formation, was investigated in six different bacterial organisms. cell-free extracts of myxococcus fulvus, staphylococcus carnosus, lactobacillus plantarum and halobacterium cutirubrum converted [14c]acetyl-coa or [14c]hydroxymethylglutaryl-coa to [14c]mevalonic acid. furthermore, [14c]mevalonic acid, [14c]mevalonate-5-phosphate and [14c]mevalonate-5-pyrophosphate were metabolized to [14c]isopentenylpyrophosphate. ...19938405922
classification of rhizomonas suberifaciens, an unnamed rhizomonas species, and sphingomonas spp. in rrna superfamily iv.thermal melting profiles of hybrids between 3h-labeled rrna of rhizomonas suberifaciens, the causal agent of corky root of lettuce, and chromosomal dnas from 27 species of gram-negative bacteria indicated that the genus rhizomonas belongs to superfamily iv of de ley. on the basis of the melting temperatures of dna hybrids with rrnas from the type strains of r. suberifaciens, sphingomonas paucimobilis, and sphingomonas capsulata, rhizomonas strains constitute a separate branch in superfamily iv, ...19938427800
purification and characterization of an oxygen-labile, nad-dependent alcohol dehydrogenase from desulfovibrio gigas.a nad-dependent, oxygen-labile alcohol dehydrogenase was purified from desulfovibrio gigas. it was decameric, with subunits of m(r) 43,000. the best substrates were ethanol (km, 0.15 mm) and 1-propanol (km, 0.28 mm). n-terminal amino acid sequence analysis showed that the enzyme belongs to the same family of alcohol dehydrogenases as zymomonas mobilis adh2 and bacillus methanolicus mdh.19938491707
cloning and expression in escherichia coli of the dnak gene of zymomonas mobilis.the dnak protein of zymomonas mobilis (dnakz) was identified and found to be 80% identical to the dnak protein of escherichia coli on the basis of the sequence of the n-terminal 21 amino acids. the dnakz gene was cloned and found to be expressed in a thermosensitive dnak mutant of escherichia coli. expression of the foreign gene restored a thermoresistant phenotype but failed to modulate the heat shock response in e. coli.19938491740
zymomonas mobilis cell viability: measurement method comparison.comparison of three different cell viability methods: slide count, plate count and methylene blue staining techniques, applied on zymomonas mobilis cultures, was performed. the slide technique proved to be faster and more accurate than the plate count method, and both of them far more reliable than the standard methylene blue method which constantly overestimated the zymomonas cell viability. the slide technique is advantageous also because it gives information on the cell morphology changes, no ...19937506015
cloning, sequencing, and expression of the zymomonas mobilis phosphoglycerate mutase gene (pgm) in escherichia coli.phosphoglycerate mutase is an essential glycolytic enzyme for zymomonas mobilis, catalyzing the reversible interconversion of 3-phosphoglycerate and 2-phosphoglycerate. the pgm gene encoding this enzyme was cloned on a 5.2-kbp dna fragment and expressed in escherichia coli. recombinants were identified by using antibodies directed against purified z. mobilis phosphoglycerate mutase. the pgm gene contains a canonical ribosome-binding site, a biased pattern of codon usage, a long upstream untransl ...19938320209
the aroq-encoded monofunctional chorismate mutase (cm-f) protein is a periplasmic enzyme in erwinia herbicola.enteric bacteria possess two species of chorismate mutase which exist as catalytic domains on the amino termini of the bifunctional phea and tyra proteins. in addition, some of these organisms possess a third chorismate mutase, cm-f, which exists as a small monofunctional protein. the cm-f gene (denoted aroq) from erwinia herbicola was cloned and sequenced for the first time. a strategy for selection by functional complementation in a chorismate mutase-free escherichia coli background was devise ...19938335631
mutational analysis of segmental stabilization of transcripts from the zymomonas mobilis gap-pgk operon.in zymomonas mobilis, the genes encoding glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase are transcribed together from the gap-pgk operon. however, higher levels of the former enzyme are present in the cytoplasm because of increased stability of a 5' segment containing the gap coding region. this segment is bounded by an upstream untranslated region which can be folded into many stem-loop structures and a prominent intercistronic stem-loop. mutations eliminating a proposed s ...19938468293
isoprenoid biosynthesis in bacteria: a novel pathway for the early steps leading to isopentenyl diphosphate.incorporation of 13c-labelled glucose, acetate, pyruvate or erythrose allowed the determination of the origin of the carbon atoms of triterpenoids of the hopane series and/or of the ubiquinones from several bacteria (zymomonas mobilis, methylobacterium fujisawaense, escherichia coli and alicyclobacillus acidoterrestris) confirmed our earlier results obtained by incorporation of 13c-labelled acetate into the hopanoids of other bacteria and led to the identification of a novel biosynthetic route f ...19938240251
zymobacter palmae gen. nov., sp. nov., a new ethanol-fermenting peritrichous bacterium isolated from palm sap.zymobacter palmae gen. nov., sp. nov. was proposed for a new ethanol-fermenting bacterium that was isolated from palm sap in okinawa prefecture, japan. the bacterium is gram-negative, facultatively anaerobic, catalase-positive, oxidase-negative, nonsporeforming and peritrichously flagellated. it requires nicotinic acid for growth. it ferments hexoses, alpha-linked di- and tri-saccharides, and sugar alcohols (fructose, galactose, glucose, mannose, maltose, melibiose, saccharose, raffinose, mannit ...19938257279
nucleotide sequence of levansucrase gene (levu) of zymomonas mobilis zm1 (atcc10988).the extracellular levansucrase gene (levu) was cloned from the genomic dna of zymomonas mobilis zm1 and the nucleotide sequence of the levu structural gene was determined. the 3.1 kb ecorv-polylinker fusion dna fragment containing the levu gene had an open reading frame of 1272 bps and the deduced amino acid sequence was 423 residues long with a molecular weight of 46,725. although this protein exhibited little similarity with other known levansucrases, several well-conserved regions were observ ...19938318541
isolation, characterization and sequence analysis of the scrk gene encoding fructokinase of streptococcus mutans.a gene encoding an atp-dependent fructokinase from streptococcus mutans gs-5 was identified within a 2 kb dna fragment immediately downstream from the scra gene. the gene cloned in escherichia coli also expressed mannokinase activity. insertional inactivation of this gene in s. mutans markedly decreased both fructokinase and mannokinase activities. nucleotide sequence analysis of the 2 kb fragment revealed an orf starting 199 bp downstream from the scra gene, preceded by potential ribosome-bindi ...19938336109
glucose-fructose oxidoreductase, a periplasmic enzyme of zymomonas mobilis, is active in its precursor form.glucose-fructose oxidoreductase (gfor) is a periplasmic enzyme of the ethanologenic, gram-negative bacterium zymomonas mobilis. it contains tightly bound nadp+ as cofactor. in z. mobilis gfor-recombinant strains, a precursor form of gfor was accumulated. to assay the pregfor for its nadp(h) content and enzymatic activity, it was purified from an overproducing strain. using sds-page, the precursor subunit size was determined to approximately 45 kda (compared with a 40 kda subunit size for the mat ...19938472911
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