Publications

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the relationship between the nitrogen and carbon metabolism of clostridium acetobutylicum. 193016559425
studies on bacterial phosphatases: the decomposition of phosphoric acid esters by clostridium acetobutylicum weizmann. 193316745282
studies on bacterial phosphatases: the phosphatases of clostridium acetobutylicum weizmann and propionibacterium jensenii van niel. 193316745283
the amylase of clostridium acetobutylicum. 193516559857
the activation of the butanol-acetone fermentation of carbohydrates by clostridium acetobutylicum (weizmann). 193716746380
the specific nutritive requirements of clostridium acetobutylicum (weizmann). ii. 193916747043
on the use of hydrolyzed wheat mash for the enrichment of clostridium acetobutylicum. 194316560692
the amylase and maltase of clostridium acetobutylicum. 194516747844
the inactivation of iron by 2,2'-bipyridine and its effect on riboflavin synthesis by clostridium acetobutylicum. 194521008309
determination of the effect of irradiation by x-ray on p-aminobenzoic acid, using clostridium acetobutylicum for assay. 194621023961
influence of iron concentration and attenuation on the metabolism of clostridium acetobutylicum. 194621064680
relations of strain variation and culture history to the synthesis of riboflavin by clostridium acetobutylicum in whey. 194621064681
the formation of lactic acid by clostridium acetobutylicum (weizmann). 194720240450
the maltase of clostridium acetobutylicum; its specificity range and mode of action. 195014803428
the amylase of clostridium acetobutylicum. 195214938342
[fixation of atmospheric nitrogen by granulobacter pectinovorum and bac. felsineus in flax retting]. 195214940696
triosephosphates and pyruvic acid intermediates in fermentations of pentoses by living cells of clostridium acetobutylicum. 195214945391
[occurrence of stellate forms in granulobacter pectinovorum]. 195313066046
[studies on proteolytic properties of clostridium acetobutylicum in the dynamics of fermentation]. 195313165065
[effect of reaction of the medium on the course of flax retting and on the development of bac. felsineus and on granulobacter pectinovorum in pure cultures]. 195313165067
[biosynthesis of riboflavin by clostridium acetobutylicum]. 195413190572
[iron requirement by clostridium acetobutylicum]. 195414383334
[bacteriophage of the causative agent of acetobutylic fermentation clostridium acetobutylicum]. 195613321530
[culture of clostridium pectinovorum (granulobacter pectinovorum) in anaerobic surface conditions]. 195613348110
[effect of penicillin on synthesis of acetone by clostridium acetobutylicum]. 195613394253
[role of proteolytic enzymes of clostridium acetobutylicum in aceto-butylic fermentation]. 195613407444
[not available]. 195713437487
[effect of iron on metabolism of clostridium acetobutylicum]. 195713451186
synthesis of riboflavin by microorganisms. i. the metabolic function of aspartate in the riboflavin synthesis by clostridium acetobutylicum. 195813564619
synthesis of riboflavin by microorganisms. ii. the green and violet fluorescent compounds produced in the culture filtrate of clostridium acetobutylicum. 195813588754
the amylase of clostridium acetobutylicum. ii. adsorption. 195913650514
[a study of continuous acetone butylic fermentation caused by clostridium acetobutylicum]. 196013717300
a study of the influence of hydrogen ion concentration of the culture media on the formation of acetone and butanol by clostridium pasteurianum, clostridium butylicus and clostridium acetobutylicum using sucrose as substrate ina synthetic media. 196013863960
[fermentation of calcium salts of acetic and butyric acids by clostridium acetobutylicum]. 196014425929
[raffinose fermentation with clostridium acetobutylicum]. 19666002779
[enzymatic conversion of n-butyraldehyde to n-butanol in clostridium acetobutylicum]. 19684298012
[study of the formation of n-butanol in clostridium acetobutylicum]. 19694309217
[reducation of nad linked with the presence of ferredoxin by acellular extracts of clostridium acetobutylicum]. 19704317339
the alcohol dehydrogenase of clostridium acetobutylicum. 19705500282
the ferredoxin-dependent reduction of chloramphenicol by clostridium acetobutylicum. 19715137676
oxygen and the growth and metabolism of clostridium acetobutylicum. 19714332793
effect of metronidazole on hydrogen production by clostridium acetobutylicum. 19725052040
purification and characterization of cortonase from clostridium acetobutylicum. 19725057466
study of antibacterial activity and bacteriology of latex from asclepias syriaca l.whole and fractionated latex of asclepias syriaca was tested for antimicrobial or growth-promoting activity with 16 genera and species of bacteria. latex and extracted fractions (distilled water, acetic acid, sodium bicarbonate, sulfuric acid, and ethyl ether) possessed no detectable antimicrobial activity. comparison of growth curves of selected bacteria incubated with serum and rubber fractions, as well as controls, revealed no detectable inhibition of growth, except for a slight inhibitory re ...19734790590
regulation of the nadh and nadph-ferredoxin oxidoreductases in clostridia of the butyric group.nadh and nadph-ferredoxin oxidoreductases have been studied in clostridium acetobutylicum, cl. tyrobutyricum and cl. pasteurianum. the study of the distribution and regulation of these enzymatic activities in well-defined culture conditions, reveals that the essential function of nadph-ferredoxin oxidoreductase is to produce nadph, while nadh-ferredoxin oxidoreductase can, depending on cellular conditions, produce or oxidize nadh. when these clostridia use glycolysis, regulation of the nadh-ferr ...19763218
the fermentative production of acetone-butanol by clostridium acetobutylicum.fourteen different media were used in the fermentative production of acetone-butanol. the highest total yields were achieved in medium i. potato starch and soluble starch were suitable as carbon sources. the best concentrations of potato starch and soluble starch were 500.0 and 10.0 g/l, respectively. peptone was the most favourable nitrogen source. the best concentration of peptone was 4.0 g/l. calcium carbonate in 3.6 g/l acted as buffering agent in the fermentation process. the best initial p ...197616418
study of the nadh and nadph-ferredoxin oxidoreductase activities in clostridium acetobutylicum.the nadh and nadph-ferredoxin oxidoreductase have been studied in clostridium acetobutylicum. acetyl-coa is an obligatory activator of nadh-ferredoxin reductase activity and nadh a competitive inhibitor of ferredoxin-nad+ reductase activity. these regulations are the same when c. acetoburylicum moves from 'butylic-type metabolism' to 'butyric-type metabolism'; this demonstrates that nadh-ferredoxin oxidoreductase cna, through its reversible action, meet the very different cell needs imposed by t ...197713922
microbiological production of acetone-butanol by clostridium acetobutylicum.trials succeeded in raising the efficiencies of the fermentation medium, used in the fermentative production of acetone-butanol by clostridium acetobutylicum. egyptian black strap molasses (50.0% sugars) was suitable as carbon source in the fermentation medium, and (nh4)2so4 was utilized with great success as inorganic nitrogen source. 140.0 g/l black strap molasses (about 7.0% sugars) and 3.0 g/l (nh4)2so4 were the optimum concentrations for obtaining good yields of acetone and butanol. molasse ...1978685531
bacteriocin production by clostridium acetobutylicum in an industrial fermentation process.high titers of a noninducible bacteriocin were produced by clostridium acetobutylicum in a molasses fermentation medium used for the industrial production of solvents. release of the bacteriocin towards the end of the exponential growth phase was accompanied by lysis of the culture and inhibition of the production of solvents. the producer cells were sensitive to the bacteriocin, which only affected other c. acetobutylicum strains and a clostridium felsineum strain. the thermolabile bacteriocin ...197936841
isolation and properties of reduced nicotinamide adenine dinucleotiderubredoxin oxidoreductase of clostridium acetobutylicum. 1979526302
inhibition of ribonucleic acid polymerase by a bacteriocin from bacteroides fragilis.the bacteroides fragilis bacteriocin which inhibits ribonucleic acid (rna) polymerase activity had a narrow activity spectrum in vivo and only inhibited the growth of certain b. fragilis strains. in vitro the bacteriocin was not specific and inhibited rna polymerases from widely diverse bacterial genera. rna polymerases from rifampin-resistant strains of bacteroides thetaiotaomicron and clostridium acetobutylicum were resistant to the bacteriocin in vitro. purified bacteriocin bound to partially ...19816177280
enoyl-coa hydratases from clostridium acetobutylicum and escherichia coli. 19817024731
feasible improvements of the butanol production by clostridium acetobutylicum. 19817271717
carboxymethyl cellulase and cellobiase production by clostridium acetobutylicum in an industrial fermentation medium.the production of a carboxymethyl cellulase and a cellobiase by clostridium acetobutylicum was demonstrated. in liquid medium the carboxymethyl cellulase was induced by molasses, and it was not repressed by glucose. optimum carboxymethyl cellulase activity occurred at ph 4.6 and 37 degrees c.19816786219
purification and characterization of an autolysin from clostridium acetobutylicum.a proteinaceous substance with antibiotic-like activity, resembling that of a bacteriocin, was isolated from an industrial-scale acetone-butanol fermentation of clostridium acetobutylicum. the substance, purified by acetone precipitation, diethylaminoethyl cellulose chromatography, and polyacrylamide gel electrophoresis, was characterized as a glycoprotein with a molecular weight of 28,000. the glycoprotein was partially inactivated by certain protease enzymes. it had no effect on deoxyribonucle ...198116345710
autolytic activity and an autolysis-deficient mutant of clostridium acetobutylicum.the optimum conditions for autolysis and autoplast formation in clostridium acetobutylicum p262 have been defined. autolysis was optimal at ph 6.3 in 0.04 m sodium phosphate buffer, and the bacterium produced latent and active forms of an autolytic enzyme. the ability of cells to autolyze decreased sharply when cultures entered the stationary phase. autoplasts were induced by 0.25 to 0.5 m sucrose and were stable in media containing sucrose, cacl(2), and mgcl(2). a pleiotropic autolysis-deficien ...198116345906
clostridium acetobutylicum protoplast formation and regeneration.techniques and media for the production and regeneration of stable clostridium acetobutylicum protoplasts are described.198216345980
solvent production and morphological changes in clostridium acetobutylicum.the morphological and cytological changes which occurred in clostridium acetobutylicum p262 during the production of acetone, butanol, and ethanol in an industrial fermentation medium were identified and correlated with the growth and physiological changes. the swollen, cigar-shaped clostridial forms were involved in the conversion of acids to neutral solvents, and there was a correlation between the number of clostridial forms and the production of solvents. sporulation mutants which were unabl ...198216346038
autolytic activity and butanol tolerance of clostridium acetobutylicum.the effects of acetone and butanol on the growth of vegetative cells and the stability of swollen-phase bright-stationary-phase cells (clostridial forms) of clostridium acetobutylicum p262 and an autolytic deficient mutant (lyt-1) were investigated. there was little difference in the sensitivity of strain p262 and the lyt-1 mutant vegetative cells and clostridial forms to acetone. the stability of the different morphological stages was unaffected by acetone concentrations far in excess of those ...198216346145
acetone and butanol production by clostridium acetobutylicum in a synthetic medium.the effect of the component concentrations of a synthetic medium on acetone and butanol fermentation by clostridium acetobutylicum atcc 824 was investigated. cell growth was dependent on the presence of mg, fe, and k in the medium. mg and mn had deleterious effects when in excess. ammonium acetate in excess caused acid fermentation. the metabolism was composed of two phases: an acid phase and a solvent one. low concentrations of glucose allowed the first phase only. the theoretical ratio of the ...198216346149
lipid composition in the classification of the butyric acid-producing clostridia.an examination of 20 strains of butyric acid-producing clostridium species for phospholipid class compositions, plasmalogen content, and acyl and alk-l-enyl chains showed that the deoxyribonucleic acid homology groups i (clostridium butyricum) and ii (clostridium beijerinckii) could be distinguished by their lipid compositions. the phospholipids of c. butyricum strains had ethanolamine as the major nitrogenous lipid polar head-group moiety, more octadecenoate plus c19-cyclopropane than hexadecen ...19836886674
[effect of growth phase and composition of the medium on the rate of biosynthesis of nadh: rubredoxin oxidoreductase in clostridium acetobutylicum].among the three strains of clostridium acetobutylicum we investigated: nrrl 592, ncib 619 and atcc 824, only the last was shown to contain a nadh: rubredoxin oxidoreductase activity. we report that the biosynthesis rate of this enzyme fluctuated in the proportions of 1 to 50 according to the growth phase and medium composition. these variations reflect a mode of regulation adjusted to the metabolism of bacteria.19836409358
plasmid detection and isolation in strains of clostridium acetobutylicum and related species.twenty-one strains of clostridium acetobutylicum, c. butylicum and clostridium saccharoperbutylacetonicum were examined. seven of them contained extrachromosomal dna molecules, with a size ranging from 2.6 to more than 50 megadaltons. strain m1 carries a small plasmid of 2.6 megadaltons, ab10 at least one plasmid of 2.6 megadaltons, ab12 one plasmid of 5.2 megadaltons, ab14 and ab16 a plasmid of about 7 megadaltons and a large one of more than 50 megadaltons, ab17 carries at least one plasmid of ...19836574306
utilization of enzymatically hydrolyzed wood hemicelluloses by microorganisms for production of liquid fuels.hemicellulose-derived sugars were obtained from a variety of pretreated wood substrates such as water-soluble fractions from steam-exploded aspen, solvent-extracted aspen, and commercial xylan. these fractions were enzymatically hydrolyzed by commercial enzyme preparations and by the culture filtrates of eight highly cellulolytic fungi. the sugars released were assayed by high-pressure liquid chromatography. over 30% of the hemicellulose fractions, at a 10% substrate concentration, could be hydr ...198316346161
transformation of clostridium acetobutylicum protoplasts with bacteriophage dna.techniques for the transformation of clostridium acetobutylicum protoplasts with bacteriophage dna are described. transformation required regeneration of protoplasts and a 2-h eclipse period.198316346174
butanol production by a butanol-tolerant strain of clostridium acetobutylicum in extruded corn broth.by employing serial enrichment, a derivative of clostridium acetobutylicum atcc 824 was obtained which grew at concentrations of butanol that prevented growth of the wild-type strain. the parent strain demonstrated a negative growth rate at 15 g of butanol/liter, whereas the sa-1 mutant was still able to grow at a rate which was 66% of the uninhibited control. sa-1 produced consistently higher concentrations of butanol (from 5 to 14%) and lower concentrations of acetone (12.5 to 40%) than the wi ...198316346258
sporulation of clostridium acetobutylicum p262 in a defined medium.a defined minimal sporulation medium for clostridium acetobutylicum p262, which produces high levels of solvents, is described. the overall sporulation sequence was similar to that of other endospore-forming bacteria. however, we observed a presporulation stage, during which swollen phase-bright cells which contained large amounts of granulose formed. during sporulation, the initiation of spore coat formation occurred before the onset of cortex formation. other clostridium strains tested showed ...198316346276
selection of bacteria with favorable transport properties through porous rock for the application of microbial-enhanced oil recovery.this paper presents a bench-scale study on the transport in highly permeable porous rock of three bacterial species-bacillus subtilis, pseudomonas putida, and clostridium acetobutylicum-potentially applicable in microbial-enhanced oil recovery processes. the transport of cells during the injection of bacterial suspension and nutrient medium was simulated by a deep bed filtration model. deep bed filtration coefficients and the maximum capacity of cells in porous rock were measured. low to interme ...198316346414
effect of butanol on lipid composition and fluidity of clostridium acetobutylicum atcc 824.butanol, at sub-growth-inhibitory levels, caused a ca. 20 to 30% increase in fluidity of lipid dispersions from clostridium acetobutylicum. when grown in the presence of butanol or into stationary phase, c. acetobutylicum synthesized increased levels of saturated acyl chains at the expense of unsaturated chains.19846696415
intermediary metabolism in clostridium acetobutylicum: levels of enzymes involved in the formation of acetate and butyrate.the levels of seven intermediary enzymes involved in acetate and butyrate formation from acetyl coenzyme a in the saccharolytic anaerobe clostridium acetobutylicum were investigated as a function of time in solvent-producing batch fermentations. phosphate acetyltransferase and acetate kinase, which are known to form acetate from acetyl coenzyme a, both showed a decrease in specific activity when the organism reached the solvent formation stage. the three consecutive enzymes thiolase, beta-hydrox ...198416346566
transformation of heat-treated clostridium acetobutylicum protoplasts with pub110 plasmid dna.heat treatment of clostridium acetobutylicum sa-1 protoplasts at 55 degrees c for 15 min before transformation resulted in expression in this microorganism of the kanamycin resistance determinant associated with plasmid pub110. no heat treatment, or heat treatment at 65 or 44 degrees c for various time intervals, resulted in no kanamycin resistance transformants being recovered on selective kanamycin-containing regeneration medium. dnase plate assay indicated that treatment at 55 degrees c for 1 ...198416346641
control of carbon and electron flow in clostridium acetobutylicum fermentations: utilization of carbon monoxide to inhibit hydrogen production and to enhance butanol yields.extracts prepared from non-solvent-producing cells of clostridium acetobutylicum contained methyl viologen-linked hydrogenase activity (20 u/mg of protein at 37 degrees c) but did not display carbon monoxide dehydrogenase activity. co addition readily inhibited the hydrogenase activity of cell extracts or of viable metabolizing cells. increasing the partial pressure of co (2 to 10%) in unshaken anaerobic culture tube headspaces significantly inhibited (90% inhibition at 10% co) both growth and h ...198416346643
selection of an asporogenous strain of clostridium acetobutylicum in continuous culture under phosphate limitation.based on the observation that cells of clostridium acetobutylicum unable to store granulose do not initiate sporulation, a staining procedure was developed for the detection of asporogenous mutants. by application of this procedure it was shown that an asporogenous strain of c. acetobutylicum was selected in continuous culture under phosphate limitation.198416346665
production of solvents by clostridium acetobutylicum cultures maintained at neutral ph.the formation of acetone and n-butanol by clostridium acetobutylicum ncib 8052 (atcc 824) was monitored in batch culture at 35 degrees c in a glucose (2% [wt/vol]) minimal medium maintained throughout at either ph 5.0 or 7.0. at ph 5, good solvent production was obtained in the unsupplemented medium, although addition of acetate plus butyrate (10 mm each) caused solvent production to be initiated at a lower biomass concentration. at ph 7, although a purely acidogenic fermentation was maintained ...198416346678
mutagenesis of clostridium acetobutylicum.mutagenesis of the obligate anaerobe clostridium acetobutylicum was best accomplished using agents (e.g. ethyl methane sulphonate or n-methyl-n'-nitro-n-nitrosoguanidine) which are believed to act by a direct mutagenic mechanism. other agents (e.g. u.v. radiation) whose effectiveness relies on misrepair of damaged dna via an error-prone pathway, were poor mutagens of this organism. procedures are described which readily yielded a variety of auxotrophic and other useful mutant strains of cl. acet ...19853928568
conjugal transfer of plasmid-mediated antibiotic resistance from streptococci to clostridium acetobutylicum.three broad host-range mls plasmids, pam beta 1 (em), pip501 (em, cm) and pjh4 (em, sm, km), were transferred by a conjugation-like process from streptococcus faecalis to clostridium acetobutylicum. the plasmids were stably maintained and antibiotic resistances were fully expressed in c. acetobutylicum, except for chloramphenicol resistance, which was poorly expressed, if at all. the c. acetobutylicum strains harbouring every plasmid could be used as donors in intraspecific matings with frequenc ...19853938632
regulation and butanol inhibition of d-xylose and d-glucose uptake in clostridium acetobutylicum.clostridium acetobutylicum exhibited diauxie growth in the presence of mixtures of glucose and xylose. both glucose- and xylose-grown cells had a glucose uptake activity. on the other hand, growth on xylose was associated with the induction of a xylose permease activity, which was repressed by glucose in xylose-induced cells. the rate of sugar uptake with increasing sugar concentrations showed saturation kinetics with an apparent km of 1.25 x 10(-5) m for glucose and 5 x 10(-3) m for xylose. con ...19854004220
differential levels of ferredoxin and rubredoxin in clostridium acetobutylicum.ferredoxin and rubredoxin levels have been determined in deae-cellulose treated extracts of clostridium acetobutylicum using specific enzymatic assays. in contrast to ferredoxin, the content of rubredoxin is affected by various culture conditions; it fluctuates in the proportions of 1 to 3 according to the growth phase, 1 to 8 according to the medium composition, and 1 to 40 according to the ph. highest rubredoxin level is obtained at the end of the acid phase when the cells grow in chemically d ...19854005308
transmembrane ph gradient and membrane potential in clostridium acetobutylicum during growth under acetogenic and solventogenic conditions.the proton motive force and its electrical and chemical components were determined in clostridium acetobutylicum, grown in a phosphate-limited chemostat, using [14c]dimethyloxazolidinedione and [14c]benzoic acid as transmembrane ph gradient (delta ph) probes and [14c]triphenylmethylphosphonium as a membrane potential (delta psi) indicator. the cells maintained an internal-alkaline ph gradient of approximately 0.2 at ph 6.5 and 1.5 at ph 4.5. the delta ph was essentially constant between ph 6.5 a ...19854083872
isolation and characterization of butanol-resistant mutants of clostridium acetobutylicum.in a wild-type strain of clostridium acetobutylicum isolated from soil, solvent production appeared limited by butanol toxicity. butanol-resistant mutants have been obtained which produced significantly higher solvent concentrations (about 30%) than the wild-type strain. some other physiological differences were observed between a selected resistant mutant and the wild-type strain at the level of solvent resistance and sporulation.19854091556
effects of butanol on clostridium acetobutylicum.the internal ph of clostridium acetobutylicum was determined at various stages during the growth of the organism. even in the presence of significant quantities of acetic, butyric, and lactic acids, an internal ph of 6.2 was maintained. experiments using n,n'-dicyclohexylcarbodiimide indicated that a functioning h+-atpase is necessary for internal ph control. butanol, one of the end products of the fermentation, had numerous harmful effects on c. acetobutylicum. at a concentration high enough to ...19852868690
modulation of acetone-butanol-ethanol fermentation by carbon monoxide and organic acids.metabolic modulation of acetone-butanol-ethanol fermentation by clostridium acetobutylicum with carbon monoxide (co) and organic acids is described. co, which is a known inhibitor of hydrogenase, was found to be effective in the concentration range of dissolved co corresponding to a co partial pressure of 0.1 to 0.2 atm. metabolic modulation by co was particularly effective when organic acids such as acetic and butyric acids were added to the fermentation as electron sinks. the uptake of organic ...198516346746
cellulolytic activity of clostridium acetobutylicum.clostridium acetobutylicum nrrl b527 and atcc 824 exhibited extracellular and cell-bound endoglucanase and cellobiase activities during growth in a chemically defined medium with cellobiose as the sole source of carbohydrate. for both strains, the endoglucanase was found to be mainly extracellular (70 to 90%) during growth in continuous or batch cultures with the ph maintained at 5.2, whereas the cellobiase was mainly cell associated (60 to 90%). during continuous cultivation of strain b527 with ...198516346847
immobilized clostridium acetobutylicum p262 mutants for solvent production.the production of acetone, butanol, and ethanol by two immobilized, sporulation-deficient (spo) clostridium acetobutylicum p262 mutants which were held in the solventogenic phase was investigated. the spoa2 mutant, which was an early-sporulation mutant and did not form a forespore septum, produced higher solvent yields than did the spob mutant which was a late-sporulation mutant and was blocked at a stage after forespore septum formation. the spoa2 mutant was also granulose and capsule negative. ...198516346864
xylanolytic activity of clostridium acetobutylicum.of 20 strains of clostridium spp. screened, 17 hydrolyzed larch wood xylan. two strains of clostridium acetobutylicum, nrrl b527 and atcc 824, hydrolyzed xylan but failed to grow on solid media with larch xylan as the sole carbon source; however, strain atcc 824 was subsequently found to grow on xylan under specified conditions in a chemostat. these two strains possessed cellulolytic activity and were therefore selected for further studies. in cellobiose-limited continuous cultures, strain nrrl ...198516346904
acetone-butanol fermentation and its variants.recent intensive research on the acetone-butanol-ethanol and the isopropanol-butanol-ethanol fermentation has increased the basic understanding of these processes substantially. metabolic investigations on clostridium acetobutylicum, and clostridium beijerinkii show that enzyme activities necessary for solvent production are induced only in solvent-producing cells. although produced, or added, acetic and butyric acid have significant effects on the metabolic activities, the transition from acid ...198514541776
the effect of ph on nitrogen supply, cell lysis, and solvent production in fermentations of clostridium acetobutylicum.in batch fermentations of c. acetobutylicum, with 5 g/l yeast extract and 50mm glucose, the ratio of ammonium to glucose affected solvent production when the ph was left to vary uncontrolled from 4.5 to 3.65. high solvent production was observed for a low ratio. when the ph was controlled at 4.5, only acids were produced for all ratio values. at a low ammonium-to-glucose ratio, solvents were produced when the ph was controlled at 3.7. acids only were produced for a low ratio value at ph 4.0 or f ...198518553724
importance of agitation in acetone-butanol fermentation.the specific rates of anaerobic solvent production by clostridium acetobutylicum increased with increasing fermentor impeller speed from 190 to 340 rpm (n(re) = 3.93 x 10(4)). the maximum values were 5.54, 3.85, and 0.8 mmol/h . g cell for butanol, acetone, and ethanol, respectively. corresponding rates for respective gases produced were 11.60 and 15.88 mmol/h . g cell for h(2) and co(2). further increases in agitation speed resulted in generally decreasing specific production rates to the point ...198518553818
cloning and expression of clostridium acetobutylicum endoglucanase, cellobiase and amino acid biosynthesis genes in escherichia coli.clostridium acetobutylicum p262 endoglucanase and cellobiase genes, cloned on a 4.9 kb dna fragment in the recombinant plasmid phz100, were expressed from their own promoter in escherichia coli. active carboxymethylcellulase and cellobiase enzymes were produced, but there was no degradation of avicel. the endoglucanase activities observed in cell extracts of e. coli hb101(phz100) differed in their ph and temperature optima from those previously reported for c. acetobutylicum p270. complementatio ...19863021896
amino acid sequence of the pyruvate and the glyoxylate active-site lysine peptide of escherichia coli 2-keto-4-hydroxyglutarate aldolase.pure 2-keto-4-hydroxyglutarate aldolase of escherichia coli, a "lysine-type" trimeric enzyme which has the unique properties of forming an "abortive" schiff-base intermediate with glyoxylate (the aldehydic product/substrate) and of showing strong beta-decarboxylase activity toward oxalacetate, binds any one of its substrates (2-keto-4-hydroxyglutarate, pyruvate, or glyoxylate) in a competitive manner. to determine whether the substrates bind at the same or different (juxta-positioned) sites and ...19863090043
[role of acetate and butyrate in the induction of nadh: rubredoxin oxidoreductase in clostridium acetobutylicum].study of the biosynthesis of nadh: rubredoxin oxidoreductase in resting cells of clostridium acetobutylicum shows that this enzyme is synthesized at a maximal rate in the presence of acetic acid at a concentration of 3 g . l-1 and at ph 4.8. protons do not play any role in this biosynthesis since no induction is observed in a medium without acetate for the same values of ph. butyric acid at a concentration of 0.5 g . l-1 gives 50% induction and formic acid, isobutyric acid and propionic acid hav ...19863091091
cloning of clostridium acetobutylicum genes and their expression in escherichia coli and bacillus subtilis.dna from clostridium acetobutylicum abkn8 was partially digested with sau3a and the fragments obtained were inserted into the unique bamhi site of the cloning vector phv33. the recombinant plasmids were used to transform escherichia coli hb101 with selection for ampicillin resistance. a collection of ampicillin-resistant, tetracycline-sensitive clones representative of the clostridium acetobutylicum genome was made. the clones were shown to carry recombinant plasmids each containing an insert of ...19863093821
gene transfer, recombination and gene cloning in clostridium acetobutylicum.although clostridium acetobutylicum has been used for over 70 years for the industrial production of solvents, it is only recently that studies on the genetics of this organism have been initiated. recent advances in the development of genetic transfer systems as well as the cloning and expression of genes from this organism in escherichia coli are reviewed.19863153137
[formation and regeneration of protoplasts of a native strain of clostridium acetobutylicum].a procedure was optimized for the formation and regeneration of protoplasts in a clostridium acetobutylicum strain isolated from cassava roots in misiones, argentina. the regeneration frequency was calculated as the ratio of regenerants (colony forming units on regeneration plates minus colony forming units from osmotically resistant cells) per initial cell number (colony forming units before protoplast formation). the percentage regeneration varied from 10 to 15%.19863685381
saccharification of concentrated brewing bagasse slurries with dilute sulfuric acid for producing acetone-butanol by clostridium acetobutylicum.a comprehensive kinetic study of the acid hydrolysis of concentrated brewing bagasse slurries was performed. the use of the simple series reaction model was found to be suitable when a "heterogeneous correction" (pseudosubstrate-inhibition) is taken into account in slurries with low liquid-to-biomass ratios. rate constants are shown to be dependent not only on temperature and acid concentration but essentially also on the initial biomass concentration. actual rate constants, activation energies, ...198618553872
the acetone butanol fermentation on glucose and xylose. i. regulation and kinetics in batch cultures.the kinetics in batch culture of the acetone butanol fermentation by clostridium acetobutylicum is compared on glucose, xylose, and mixtures of both sugars. the fastest initial growth and transition from an acid to a solvent metabolism occurs on glucose, with a final 62 g/l glucose conversion. on xylose, an initial slower growth rate and a longer metabolic transition result in higher cellular and acids concentration, thus in a level of fermented sugar limited to 47 g/l. batch fermentations on mi ...198618555310
the acetone butanol fermentation on glucose and xylose. ii. regulation and kinetics in fed-batch cultures.the kinetics in fed-batch cultures of acetone butanol fermentation by clostridium acetobutylicum is compared on glucose, xylose, and mixtures of both sugars. the final conversion yield of sugars into solvents always increases with the sugar feeding rate. at low feeding rates, the sugar concentration in the medium becomes limiting, which results in a slower cellular growth, a slower metabolic transition from an acid to a solvent fermentation and, thus, a higher accumulation of acids. it is only a ...198618555311
the release of fermentable carbohydrate from peat by steam explosion and its use in the microbial production of solvents.steam treatment of peat at 200 degrees c for 3 min, followed by instantaneous decompression (steam explosion), solubilized up to 28% of the dry matter. seventy-five percent of the solubilized material was carbohydrate, 33% of which was composed of mono- and disaccharides, including galactose, glucose, xylose, mannose, arabinose, and cellobiose, in order of decreasing concentration. the solubilized materials served as the sole source of carbohydrate for growth and solvent production by clostridiu ...198618555312
mathematical model of a batch acetone-butanol fermentation.a mathematical model for the batch culture of clostridium acetobutylicum was formulated using experimental data for anaerobic solvent production. the model summarizes biochemical as well as physiological aspects of growth and metabolite synthesis by the production strain. the key fermentation rates are expressed and evaluated with regard to substrate consumption and butanol end-product inhibitory effects. parametric sensitivity analysis of the batch process model was carried out, indicating the ...198618555322
systems analysis of the culture physiology in acetone-butanol fermentation.the pronounced differences in performance of a strain of clostridium acetobutylicum atcc 824 were analyzed by the method of systems analysis. the mechanism for cellular transport of substrate (glucose), solvents, and acids was studied and mathematically formulated. the systems analysis approach in the treatment of data from culture experiments pointed out the cell membrane malfunction indicated by its altered permeability and reflected in the altered number of active sugar transport sites. exper ...198618561223
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