Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [biosynthesis of riboflavin by clostridium acetobutylicum]. | 1954 | 13190572 | |
| [bacteriophage of the causative agent of acetobutylic fermentation clostridium acetobutylicum]. | 1956 | 13321530 | |
| [culture of clostridium pectinovorum (granulobacter pectinovorum) in anaerobic surface conditions]. | 1956 | 13348110 | |
| [effect of penicillin on synthesis of acetone by clostridium acetobutylicum]. | 1956 | 13394253 | |
| [role of proteolytic enzymes of clostridium acetobutylicum in aceto-butylic fermentation]. | 1956 | 13407444 | |
| [not available]. | 1957 | 13437487 | |
| [effect of iron on metabolism of clostridium acetobutylicum]. | 1957 | 13451186 | |
| synthesis of riboflavin by microorganisms. i. the metabolic function of aspartate in the riboflavin synthesis by clostridium acetobutylicum. | 1958 | 13564619 | |
| synthesis of riboflavin by microorganisms. ii. the green and violet fluorescent compounds produced in the culture filtrate of clostridium acetobutylicum. | 1958 | 13588754 | |
| the amylase of clostridium acetobutylicum. ii. adsorption. | 1959 | 13650514 | |
| [a study of continuous acetone butylic fermentation caused by clostridium acetobutylicum]. | 1960 | 13717300 | |
| 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. | 1960 | 13863960 | |
| [iron requirement by clostridium acetobutylicum]. | 1954 | 14383334 | |
| [fermentation of calcium salts of acetic and butyric acids by clostridium acetobutylicum]. | 1960 | 14425929 | |
| cloning, characterization, and functional expression of the klebsiella oxytoca xylodextrin utilization operon (xyntb) in escherichia coli. | escherichia coli is being developed as a biocatalyst for bulk chemical production from inexpensive carbohydrates derived from lignocellulose. potential substrates include the soluble xylodextrins (xyloside, xylooligosaccharide) and xylobiose that are produced by treatments designed to expose cellulose for subsequent enzymatic hydrolysis. adjacent genes encoding xylobiose uptake and hydrolysis were cloned from klebsiella oxytoca m5a1 and are functionally expressed in ethanologenic e. coli. the xy ... | 2003 | 14532050 |
| 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 ... | 1985 | 14541776 |
| mutagenicity of nitroaromatic degradation compounds. | the mutagenicity of 2,4-dinitrotoluene (24dnt), and 2,6-dinitrotoluene (26dnt), and their related transformation products such as hydroxylamine and amine derivatives, which are formed by clostridium acetobutylicum, were tested in crude cell extracts using salmonella typhimurium ta100. a previous publication already reported the mutagenic activities of 2,4,6-trinitrotoluene (tnt) and its related hydroxylamine derivatives in this test system. a time course of the mutagenicity during the anaerobic ... | 2003 | 14551991 |
| phylogenetic reconstruction of gram-positive organisms based on comparative sequence analysis of molecular chaperones from the ruminal microorganism ruminococcus flavefaciens fd-1. | primers designed on the basis of nucleotide sequences conserved in dnak and groel from gram-positive organisms were used to pcr amplify internal regions of the cognate genes from the anaerobic ruminal cellulolytic bacterium ruminococcus flavefaciens fd-1. genome walking was then utilized to elucidate the remainder of the sequences in addition to upstream and downstream regions. the full sequence of the gene encoding the groes protein (groes) was found directly upstream from groel. the deduced am ... | 2003 | 14568141 |
| genes malh and pagl of clostridium acetobutylicum atcc 824 encode nad+- and mn2+-dependent phospho-alpha-glucosidase(s). | the genome of clostridium acetobutylicum 824 contains two genes encoding nad+, mn2+, and dithiothreitol-dependent phospho-alpha-glucosidases that can be assigned to family 4 of the glycosylhydrolase superfamily. the two genes, designated malh (maltose 6-phosphate hydrolase) and pagl (phospho-alpha-glucosidase), respectively, reside in separate operons that also encode proteins of the phosphoenolpyruvate-dependent:sugar phosphotransferase system. c. acetobutylicum grows on a variety of alpha-link ... | 2004 | 14570887 |
| analysis of the elements of catabolite repression in clostridium acetobutylicum atcc 824. | the ptsh gene, encoding the phosphotransferase protein hpr, from clostridium acetobutylicum atcc 824 was identified from the genome sequence, cloned and shown to complement a ptsh mutant of escherichia coli. the deduced protein sequence shares significant homology with hpr proteins from other low-gc gram-positive bacteria, although the highly conserved sequence surrounding the ser-46 phosphorylation site is not well preserved in the clostridial protein. nevertheless, the hpr was phosphorylated i ... | 2003 | 14593248 |
| production of heterologous and chimeric scaffoldins by clostridium acetobutylicum atcc 824. | clostridium acetobutylicum atcc 824 converts sugars and various polysaccharides into acids and solvents. this bacterium, however, is unable to utilize cellulosic substrates, since it is able to secrete very small amounts of cellulosomes. to promote the utilization of crystalline cellulose, the strategy we chose aims at producing heterologous minicellulosomes, containing two different cellulases bound to a miniscaffoldin, in c. acetobutylicum. a first step toward this goal describes the productio ... | 2004 | 14679247 |
| characterization and development of two reporter gene systems for clostridium acetobutylicum. | the use of lacz from thermoanaerobacterium thermosulfurigenes (encoding beta-galactosidase) and lucb from photinus pyralis (encoding luciferase) as reporter genes in clostridium acetobutylicum was analyzed with promoters of genes required for solventogenesis and acidogenesis. both systems proved to be well suited and allowed the detection of differences in promoter strength at least up to 100-fold. the luciferase assay could be performed much faster and comes close to online measurement. reseque ... | 2004 | 14766557 |
| the maltase of clostridium acetobutylicum; its specificity range and mode of action. | 1950 | 14803428 | |
| the amylase of clostridium acetobutylicum. | 1952 | 14938342 | |
| [fixation of atmospheric nitrogen by granulobacter pectinovorum and bac. felsineus in flax retting]. | 1952 | 14940696 | |
| triosephosphates and pyruvic acid intermediates in fermentations of pentoses by living cells of clostridium acetobutylicum. | 1952 | 14945391 | |
| transcriptional analysis of spo0a overexpression in clostridium acetobutylicum and its effect on the cell's response to butanol stress. | spo0a is the regulator of stationary-phase events and is required for transcription of solvent formation genes in clostridium acetobutylicum. in order to elucidate the role of spo0a in differentiation, we performed transcriptional analysis of 824(pmspoa) (a spo0a-overexpressing c. acetobutylicum strain with enhanced sporulation) against a plasmid control strain. dna microarray data were contrasted to data from a spo0a knockout strain (sko1) that neither sporulates nor produces solvents. transcri ... | 2004 | 15028679 |
| transcriptional analysis of butanol stress and tolerance in clostridium acetobutylicum. | the effects of challenges with low (0.25%, vol/vol) and high (0.75%) concentrations of butanol on the growth, glucose metabolism, product formation, and transcriptional program of the solvent-tolerant clostridium acetobutylicum strain 824(pgroe1) and the plasmid control strain 824(psos95del) were used to study solvent tolerance and stress response. strain 824(pgroe1) was generated by groesl overexpression. the growth of 824(pgroe1) was less inhibited than that of 824(psos95del), and 824(pgroe1) ... | 2004 | 15028684 |
| continuous production of butanol by clostridium acetobutylicum immobilized in a fibrous bed bioreactor. | we explored the influence of dilution rate and ph in continuous cultures of clostridium acetobutylicum. a 200-ml fibrous bed bioreactor was used to produce high cell density and butyrate concentrations at ph 5.4 and 35degreesc. by feeding glucose and butyrate as a cosubstrate, the fermentation was maintained in the solventogenesis phase, and the optimal butanol productivity of 4.6 g/(l h) and a yield of 0.42 g/g were obtained at a dilution rate of 0.9 h-1 and ph 4.3. compared to the conventional ... | 2004 | 15054240 |
| sequencing and expression of the gene encoding the clostridium stercorarium beta-xylosidase xyl43b in escherichia coli. | the clostridium stercorarium f-9 xyl43b gene encoding the beta-xylosidase xyl43b consists of an open reading frame of 1,491 nucleotides that encodes a putative protein, classified in family 43, of 497 amino acids with a predicted molecular weight of 56,355. the deduced amino acid sequence of xyl43b has sequence similarity with beta-xylosidases from bacteriodes thetaiotaomicron (57% sequence identity), prevotella ruminicola (45%), streptomyces coelicolor (40%), and clostridium acetobutylicum (36% ... | 2004 | 15056894 |
| transcriptional organization of the clostridium acetobutylicum genome. | prokaryotic genes are frequently organized in multicistronic operons (or transcriptional units, tus), and usually the regulatory motifs for the whole tu are located upstream of the first tu gene. although the number of sequenced genomes has increased dramatically, experimental information on tu organization is extremely limited. even for organisms as extensively studied as escherichia coli and bacillus subtilis, tu annotation is far from complete. it therefore becomes imperative to rely on compu ... | 2004 | 15060177 |
| comparative analysis of gene expression among low g+c gram-positive genomes. | we present a comparative analysis of predicted highly expressed (phx) genes in the low g+c gram-positive genomes of bacillus subtilis, bacillus halodurans, listeria monocytogenes, listeria innocua, lactococcus lactis, streptococcus pyogenes, streptococcus pneumoniae, staphylococcus aureus, clostridium acetobutylicum, and clostridium perfringens. most enzymes acting in glycolysis and fermentation pathways are phx in these genomes, but not those involved in the tca cycle and respiration, suggestin ... | 2004 | 15069198 |
| analysis of orthologous hrca genes in escherichia coli and bacillus subtilis. | the hrca gene codes for a transcriptional repressor protein interacting with the circe operator thereby reducing expression of the groe operon of more than 120 bacterial species. at least in bacillus subtilis, the activity of the hrca protein is modulated by the groe chaperonin system. we amplified the hrca gene from five different bacterial species and analyzed its activity in escherichia coli and bacillus subtilis. while those from clostridium acetobutylicum and staphylococcus aureus turned ou ... | 2004 | 15109714 |
| thermostable xylanase10b from clostridium acetobutylicum atcc824. | the clostridium acetobutylicum xylanase gene xyn10b (cap0116) was cloned from the type strain atcc 824, whose genome was recently sequenced. the nucleotide sequence of c. acetobutylicum xyn10b encodes a 318-amino acid protein. xyn10b consists of a single catalytic domain that belongs to family 10 of glycosyl hydrolases. the enzyme was purified from recombinant escherichia coli. the xyn10b enzyme was highly active toward birchwood xylan, oat-spelt xylan, and moderately active toward avicel, carbo ... | 2004 | 15252718 |
| identification of o2-induced peptides in an obligatory anaerobe, clostridium acetobutylicum. | clostridium acetobutylicum dsm792 (=atcc824), a solvent producing obligate anaerobe, grew well after a shift in growth conditions from anoxic to microoxic at the mid exponential phase. in two-dimensional gel electrophoresis, a spot migrating at 45 kda and three spots at 23 kda accumulated after 30 min of flushing with 5% o(2)/95% n(2). based on peptide mass fingerprints, the 45 kda polypeptide was determined to be np_347663 (a-type flavoprotein homologue) and the 23 kda polypeptides were determi ... | 2004 | 15280011 |
| identification and functional analysis of dtdp-glucose-4,6-dehydratase gene and its linked gene cluster in an aminoglycoside antibiotics producer of streptomyces tenebrarius h6. | streptomyces tenebrarius h6 produces a variety of aminoglycoside antibiotics, such as apramycin, tobramycin, and kanamycin b. primers were designed according to the highly conserved sequences of the dtdp-glucose-4,6-dehydratase genes, and a 0.6-kb pcr product was obtained from s. tenebrarius h6 genomic dna. with the 0.6-kb pcr product as a probe, a bamhi 7.0-kb fragment was isolated. dna sequence analysis of the 7.0-kb fragment revealed four orfs and an incomplete orf. in search of databases, th ... | 2004 | 15297914 |
| a rubrerythrin-like oxidative stress protein of clostridium acetobutylicum is encoded by a duplicated gene and identical to the heat shock protein hsp21. | comparison of the n-terminus of the heat shock protein hsp21 of clostridium acetobutylicum with proteins predicted to be encoded by the genome of this bacterium revealed that this stress protein is encoded by two almost identical open reading frames cac3597 and cac3598. these genes encode a rubrerythrin-like protein with the rubredoxin-like fes4 domain at the n-terminus and the ferritin-like diiron domain (rubrerythrin domain) at the c-terminus. thus, the order of the two putative functional dom ... | 2004 | 15336429 |
| substrate-induced production and secretion of cellulases by clostridium acetobutylicum. | clostridium acetobutylicum atcc 824 is a solventogenic bacterium that grows heterotrophically on a variety of carbohydrates, including glucose, cellobiose, xylose, and lichenan, a linear polymer of beta-1,3- and beta-1,4-linked beta-d-glucose units. c. acetobutylicum does not degrade cellulose, although its genome sequence contains several cellulase-encoding genes and a complete cellulosome cluster of cellulosome genes. in the present study, we demonstrate that a low but significant level of ind ... | 2004 | 15345405 |
| h2-producing bacterial communities from a heat-treated soil inoculum. | hydrogen gas (approximately 60% h(2)) was produced in a continuous flow bioreactor inoculated with heat-treated soil, and fed synthetic wastewater containing glucose (9.5 g l(-1)). the ph in the bioreactor was maintained at 5.5 to inhibit consumption of h(2) by methanogens. the objective of this study was to characterize bacterial communities in the reactor operated under two different hydraulic retention times (hrts of 30-h and 10-h) and temperatures (30 degrees c and 37 degrees c). at 30-h hrt ... | 2004 | 15558274 |
| intracellular butyryl phosphate and acetyl phosphate concentrations in clostridium acetobutylicum and their implications for solvent formation. | it has been suggested (l. h. harris, r. p. desai, n. e. welker, and e. t. papoutsakis, biotechnol. bioeng. 67:1-11, 2000) that butyryl phosphate (bup) is a regulator of solventogenesis in clostridium acetobutylicum. here, we determined bup and acetyl phosphate (acp) levels in fermentations of c. acetobutylicum wild type (wt), degenerate strain m5, a butyrate kinase (buk) mutant, and a phosphotransacetylase (pta) mutant. a sensitive method was developed to measure bup and acp in the same sample. ... | 2005 | 15640230 |
| spoiie regulates sporulation but does not directly affect solventogenesis in clostridium acetobutylicum atcc 824. | using gene expression reporter vectors, we examined the activity of the spoiie promoter in wild-type and spo0a-deleted strains of clostridium acetobutylicum atcc 824. in wild-type cells, the spoiie promoter is active in a transient manner during late solventogenesis, but in strain sko1, where the sporulation initiator spo0a is disrupted, no spoiie promoter activity is detectable at any stage of growth. strains 824(pmspo) and 824(passpo) were created to overexpress spoiie and to decrease spoiie e ... | 2005 | 15743939 |
| heterologous production, assembly, and secretion of a minicellulosome by clostridium acetobutylicum atcc 824. | the gene man5k encoding the mannanase man5k from clostridium cellulolyticum was cloned alone or as an operon with the gene cipc1 encoding a truncated scaffoldin (minicipc1) of the same origin in the solventogenic clostridium acetobutylicum. the expression of the heterologous gene(s) was under the control of a weakened thiolase promoter pthl. the recombinant strains of the solventogenic bacterium were both found to secrete active man5k in the range of milligrams per liter. in the case of the stra ... | 2005 | 15746321 |
| characterization of thermostable xyn10a enzyme from mesophilic clostridium acetobutylicum atcc 824. | a thermostable xylanase gene, xyn10a (cap0053), was cloned from clostridium acetobutylicum atcc 824. the nucleotide sequence of the c. acetobutylicum xyn10a gene encoded a 318-amino-acid, single-domain, family 10 xylanase, xyn10a, with a molecular mass of 34 kda. xyn10a exhibited extremely high (92%) amino acid sequence identity with xyn10b (cap0116) of this strain and had 42% and 32% identity with the catalytic domains of rhodothermus marinus xylanase i and thermoascus aurantiacus xylanase i, r ... | 2005 | 15765251 |
| analyses of enzyme ii gene mutants for sugar transport and heterologous expression of fructokinase gene in corynebacterium glutamicum atcc 13032. | corynebacterium glutamicum atcc 13032 has four enzyme ii (eii) genes of the phosphotransferase system in its genome encoding transporters for sucrose, glucose, fructose, and an unidentified eii. to analyze the function of these eii genes, they were inactivated via homologous recombination and the resulting mutants characterized for sugar utilization. whereas the sucrose eii was the only transport system for sucrose in c. glutamicum, fructose and glucose were each transported by a second transpor ... | 2005 | 15766777 |
| functional organization of a single nif cluster in the mesophilic archaeon methanosarcina mazei strain gö1. | the mesophilic methanogenic archaeon methanosarcina mazei strain gö1 is able to utilize molecular nitrogen (n2) as its sole nitrogen source. we have identified and characterized a single nitrogen fixation (nif) gene cluster in m. mazei gö1 with an approximate length of 9 kbp. sequence analysis revealed seven genes with sequence similarities to nifh, nifi1, nifi2, nifd, nifk, nife and nifn, similar to other diazotrophic methanogens and certain bacteria such as clostridium acetobutylicum, with the ... | 2002 | 15803652 |
| expression of abrb310 and sinr, and effects of decreased abrb310 expression on the transition from acidogenesis to solventogenesis, in clostridium acetobutylicum atcc 824. | the transcription factors sinr and abrb are involved in the control of sporulation initiation in bacillus subtilis. we identified a single homologue to sinr and three highly similar homologues to abrb, designated abrb310, abrb1941, and abrb3647, in clostridium acetobutylicum atcc 824. using reporter vectors, we showed that the promoters of abrb1941 and abrb3647 were not active under the growth conditions tested. the abrb310 promoter was strongly active throughout growth and exhibited a transient ... | 2005 | 15812030 |
| secretory production of biologically active rat interleukin-2 by clostridium acetobutylicum dsm792 as a tool for anti-tumor treatment. | the search for effective means of selectively delivering high therapeutic doses of anti-cancer agents to tumors has explored a variety of systems in the last decade. the ability of intravenously injected clostridial spores to infiltrate and thence selectively germinate in the hypoxic regions of solid tumors is exquisitely specific, making this system an interesting addition to the anti-cancer therapy arsenal. to increase the number of therapeutic proteins potentially useful for cancer treatment ... | 2005 | 15869963 |
| homologous and heterologous overexpression in clostridium acetobutylicum and characterization of purified clostridial and algal fe-only hydrogenases with high specific activities. | clostridium acetobutylicum atcc 824 was selected for the homologous overexpression of its fe-only hydrogenase and for the heterologous expressions of the chlamydomonas reinhardtii and scenedesmus obliquus hyda1 fe-only hydrogenases. the three strep tag ii-tagged fe-only hydrogenases were isolated with high specific activities by two-step column chromatography. the purified algal hydrogenases evolve hydrogen with rates of around 700 micromol h(2) min(-1) mg(-1), while hyda from c. acetobutylicum ... | 2005 | 15870373 |
| genomic analysis of the protein secretion systems in clostridium acetobutylicum atcc 824. | consistent information about protein secretion in gram-positive bacteria is essentially restricted to the model organism bacillus subtilis. among genome-sequenced clostridia, clostridium acetobutylicum has been the most extensively studied from a physiological point of view and is the organism for which the largest variety of molecular biology tools have been developed. following in silico analyses, both secreted proteins and protein secretion systems were identified. the tat (twin arginine tran ... | 2005 | 15950297 |
| biosynthesis of poly (3-mercaptopropionate) and poly (3-mercaptopropionate-co-3-hydroxybutyrate) with recombinant escherichia coli. | polythioesters newly emerged as a type of novel polymer and they have showed great potential for application in industries. in this study, genes of butyrate kinase (buk) and phosphotransbutyrylase (ptb) from clostridium acetobutylicum, and poly (3-hydroxybutyrate) (phb) synthase gene from thiocapsa pfennigii were used for construction of a metabolic pathway to synthesize the polythioesters. when 3-mercaptopropionate and 3-hydroxybutyrate were fed, poly (3-mercaptopropoinate) [poly (3mp)] and pol ... | 2003 | 15966321 |
| genetic characterization of the beta-glucuronidase enzyme from a human intestinal bacterium, ruminococcus gnavus. | beta-glucuronidase activity (encoded by the gus gene) has been characterized for the first time from ruminococcus gnavus e1, an anaerobic bacterium belonging to the dominant human gut microbiota. beta-glucuronidase activity plays a major role in the generation of toxic and carcinogenic metabolites in the large intestine, as well as in the absorption and enterohepatic circulation of many aglycone residues with protective effects, such as lignans, flavonoids, ceramide and glycyrrhetinic acid, that ... | 2005 | 16000722 |
| metabolic engineering of clostridium acetobutylicum for the industrial production of 1,3-propanediol from glycerol. | clostridium butyricum is to our knowledge the best natural 1,3-propanediol producer from glycerol and the only microorganism identified so far to use a coenzyme b12-independent glycerol dehydratase. however, to develop an economical process of 1,3-propanediol production, it would be necessary to improve the strain by a metabolic engineering approach. unfortunately, no genetic tools are currently available for c. butyricum and all our efforts to develop them have been so far unsuccessful. to obta ... | 2005 | 16095939 |
| biochemical characterization of trinitrotoluene transforming oxygen-insensitive nitroreductases from clostridium acetobutylicum atcc 824. | the genes that encode oxygen-insensitive nitroreductases from clostridium acetobutylicum possessing 2,4,6-trinitrotoluene (tnt) transformation activity were cloned, sequenced and characterized. the gene products nita (mw 31 kda) and nitb (mw 23 kda) were purified to homogeneity. the nita and nitb are oxygen-insensitive nitroreductases comprised of a single nitroreductase domain. nita and nitb enzymes show spectral characteristics similar to flavoproteins. the biochemical characteristics of nita ... | 2005 | 16187099 |
| transcriptional program of early sporulation and stationary-phase events in clostridium acetobutylicum. | dna microarray analysis of clostridium acetobutylicum was used to examine the genomic-scale gene expression changes during the shift from exponential-phase growth and acidogenesis to stationary phase and solventogenesis. self-organizing maps were used to identify novel expression patterns of functional gene classes, including aromatic and branched-chain amino acid synthesis, ribosomal proteins, cobalt and iron transporters, cobalamin biosynthesis, and lipid biosynthesis. the majority of psol1 me ... | 2005 | 16199581 |
| electrotransformation of clostridium paraputrificum m-21 with some plasmids. | clostridium paraputrificum m-21 was transformed with several shuttle plasmids constructed for clostridium acetobutylicum-escherichia coli and clostridium perfringens-e. coli by electroporation. the clostridium stercorarium xylanase gene xyn10b was successfully expressed in c. paraputrificum m-21 and the expressed protein did not suffer from proteolysis by host protease(s). this system will provide us with a genetic tool for genetic and metabolic engineering of this bacterium. | 2003 | 16233526 |
| proteome analysis and comparison of clostridium acetobutylicum atcc 824 and spo0a strain variants. | the proteomic profiles of several clostridium acetobutylicum strains were compared by two-dimensional gel electrophoresis and mass spectroscopy. the proteomic profile of c. acetobutylicum wild type strain atcc 824 with and without a commonly used control plasmid and with a spo0a overexpression plasmid pmspoa was compared. a total of 2,081 protein spots were analyzed; 23 proteins were chosen to be identified of which 18 were unique and 5 were proteins located in more than one location. the protei ... | 2006 | 16308714 |
| a wide host-range metagenomic library from a waste water treatment plant yields a novel alcohol/aldehyde dehydrogenase. | using dna obtained from the metagenome of an anaerobic digestor in a waste water treatment plant, we constructed a gene library cloned in the wide host-range cosmid plafr3. one cosmid enabled rhizobium leguminosarum to grow on ethanol as sole carbon and energy source, this being due to the presence of a gene, termed adhemeta. the adhemeta protein most closely resembles the adhe alcohol dehydrogenase of clostridium acetobutylicum, where it catalyses the formation of ethanol and butanol in a two-s ... | 2005 | 16309390 |
| adaptive responses to oxygen stress in obligatory anaerobes clostridium acetobutylicum and clostridium aminovalericum. | clostridium acetobutylicum and clostridium aminovalericum, both obligatory anaerobes, grow normally after growth conditions are changed from anoxic to microoxic, where the cells consume oxygen proficiently. in c. aminovalericum, a gene encoding a previously characterized h2o-forming nadh oxidase, designated noxa, was cloned and sequenced. the expression of noxa was strongly upregulated within 10 min after the growth conditions were altered to a microoxic state, indicating that c. aminovalericum ... | 2005 | 16332833 |
| 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 ... | 1981 | 16345710 |
| 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 ... | 1981 | 16345906 |
| clostridium acetobutylicum protoplast formation and regeneration. | techniques and media for the production and regeneration of stable clostridium acetobutylicum protoplasts are described. | 1982 | 16345980 |
| 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 ... | 1982 | 16346038 |
| 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 ... | 1982 | 16346145 |
| 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 ... | 1982 | 16346149 |
| 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 ... | 1983 | 16346161 |
| 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. | 1983 | 16346174 |
| 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 ... | 1983 | 16346258 |
| 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 ... | 1983 | 16346276 |
| 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 ... | 1983 | 16346414 |
| 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 ... | 1984 | 16346566 |
| 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 ... | 1984 | 16346641 |
| 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 ... | 1984 | 16346643 |
| 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. | 1984 | 16346665 |
| 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 ... | 1984 | 16346678 |
| 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 ... | 1985 | 16346746 |
| 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 ... | 1985 | 16346847 |
| 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. ... | 1985 | 16346864 |
| 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 ... | 1985 | 16346904 |
| phosphotransferase activity in clostridium acetobutylicum from acidogenic and solventogenic phases of growth. | clostridium acetobutylicum cells, when energized with fructose, transported and phosphorylated the glucose analog 2-deoxyglucose by a phosphoenolpyruvate-dependent phosphotransferase (pt) system. butanol up to 2% did not inhibit pt activity, although its chaotropic effect on the cell membrane caused cellular phosphoenolpyruvate and the 2-deoxyglucose-6-phosphate to leak out. cells harvested from the solventogenic phase of batch growth had a significantly lower pt activity than did cells from the ... | 1986 | 16347058 |
| influence of external ph and fermentation products on clostridium acetobutylicum intracellular ph and cellular distribution of fermentation products. | clostridium acetobutylicum atcc 824 cells harvested from a phosphate-limited chemostat culture maintained at ph 4.5 had intracellular concentrations of acetate, butyrate, and butanol which were 13-, 7-, and 1.3-fold higher, respectively, than the corresponding extracellular concentrations. cells from a culture grown at ph 6.5 had intracellular concentrations of acetate and butyrate which were only 2.2-fold higher than the respective external concentrations. the highest intracellular concentratio ... | 1986 | 16347081 |
| nutritional factors affecting the ratio of solvents produced by clostridium acetobutylicum. | fermentation of whey by clostridium acetobutylicum yielded butanol and acetone in a ratio of approximately 100:1. this ratio amounted to only 2:1 in synthetic media with glucose, lactose, or glucose plus galactose as substrates. removal of citrate from whey and addition of minerals resulted in an increase in the amount of acetone produced. experiments carried out in a chemostat with a low-phosphate synthetic medium revealed that the butanol/acetone ratio could be increased from 2:1 to 3.8:1 by c ... | 1986 | 16347104 |
| characterization, biosynthesis, and regulation of granulose in clostridium acetobutylicum. | synthesis of granulose was investigated in 15 solvent-producing clostridium strains. only one of the strains did not produce granulose. the structure of granulose in clostridium acetobutylicum p262 consisted of a high-molecular-weight polyglucan containing only (1-->4) linked d-glucopyranose units. biosynthesis of granulose in c. acetobutylicum p262 was dependent on adpglucose pyrophosphorylase, and granulose synthase and mutants defective in granulose accumulation lacked either one or both enzy ... | 1986 | 16347108 |
| intracellular conditions required for initiation of solvent production by clostridium acetobutylicum. | we investigated the intracellular physiological conditions associated with the induction of butanol-producing enzymes in clostridium acetobutylicum. during the acidogenic phase of growth, the internal ph decreased in parallel with the decrease in the external ph, but the internal ph did not go below 5.5 throughout batch growth. butanol was found to dissipate the proton motive force of fermenting c. acetobutylicum cells by decreasing the transmembrane ph gradient, whereas the membrane potential w ... | 1986 | 16347119 |
| cloning, expression, and purification of glutamine synthetase from clostridium acetobutylicum. | a glutamine synthetase (gs) gene, glna, from the gram-positive obligate anaerobe clostridium acetobutylicum was cloned on recombinant plasmid phz200 and enabled escherichia coli glna deletion mutants to utilize (nh(4))(2)so(4) as a sole source of nitrogen. the cloned c. acetobutylicum gene was expressed from a regulatory region contained within the cloned dna fragment. glna expression was subject to nitrogen regulation in e. coli. this cloned glna dna did not enable an e. coli glna ntrb ntrc del ... | 1986 | 16347143 |
| production of 1,3-propanediol from glycerol by clostridium acetobutylicum and other clostridium species. | glycerol was fermented with the production of 1,3-propanediol as the major fermentation product by four strains of clostridium acetobutylicum, six of c. butylicum, two of c. beijerinckii, one of c. kainantoi, and three of c. butyricum. 1,3-propanediol was identified by its retention times in gas chromatography and high-pressure liquid chromatography and by its mass spectrum. during growth of c. butylicum b593 in a chemostat culture at ph 6.5, 61% of the glycerol fermented was converted to 1,3-pr ... | 1987 | 16347311 |
| purification and characterization of two endoxylanases from clostridium acetobutylicum atcc 824. | two endoxylanases produced by c. acetobutylicum atcc 824 were purified to homogeneity by column chromatography. xylanase a, which has a molecular weight of 65,000, hydrolyzed larchwood xylan randomly, yielding xylohexaose, xylopentaose, xylotetraose, xylotriose, and xylobiose as end products. xylanase b, which has a molecular weight of 29,000, also hydrolyzed xylan randomly, giving xylotriose and xylobiose as end products. xylanase a hydrolyzed carboxymethyl cellulose with a higher specific acti ... | 1987 | 16347312 |
| isolation and some properties of a beta-d-xylosidase from clostridium acetobutylicum atcc 824. | a beta-d-xylosidase from c. acetobutylicum atcc 824 was purified by column chromatography on cm-sepharose, hydroxylapatite, phenyl sepharose, and sephadex g-200. the enzyme had an apparent molecular weight of 224,000 as estimated by gel filtration. sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the enzyme consisted of two subunits of 85,000 and one subunit of 63,000 daltons. it exhibited optimal activity at ph 6.0 to 6.5 and 45 degrees c. the enzyme had an isoelectric poin ... | 1987 | 16347313 |
| membrane h conductance of clostridium thermoaceticum and clostridium acetobutylicum: evidence for electrogenic na/h antiport in clostridium thermoaceticum. | h conductance in de-energized cells of clostridium thermoaceticum and clostridium acetobutylicum was determined from the rate of realkalinization of the medium after an acid pulse. in both organisms, cell membrane proton permeability was increased by fermentation end products and ionophores. in c. thermoaceticum, h conductance was increased by na ions compared with k as counterions. in these cells, addition of na, but not k, elicited efflux of h; h efflux was stimulated by scn and decreased by v ... | 1987 | 16347322 |
| altered electron flow in continuous cultures of clostridium acetobutylicum induced by viologen dyes. | the physiological response of clostridium acetobutylicum to methyl and benzyl viologen was investigated. viologen dyes at low concentrations (at levels of parts per million [micrograms per milliliter]) caused significant metabolic shifts. altered electron flow appeared to direct carbon flow from acid to alcohol production accompanied by decreased hydrogen evolution. reducing equivalents normally released as free hydrogen were directed toward formation of nadh which, in turn, resulted in increase ... | 1987 | 16347357 |
| role of chemotaxis in solvent production by clostridium acetobutylicum. | the motility of clostridium acetobutylicum has been investigated during a typical batch fermentation process for solvent production. the motility is characterized by "runs" during the early phase of sugar utilization and acid production, but this changes to "tumbles" during the onset of solventogenesis. sugars and undissociated acetic and butyric acids have been shown to be attractants for the bacterium, while acetone, butanol, ethanol, and dissociated acetate and butyrate are repellents. it is ... | 1987 | 16347417 |
| a technique for predicting the solvent-producing ability of clostridium acetobutylicum. | changes in colony morphology were associated with the degeneration of solvent-producing strains of clostridium acetobutylicum. the most efficient solvent-producing strains gave rise exclusively to colonies with dense centers containing large numbers of spores. many outgrowths of various morphologies developed from the perimeter of such colonies after several days of incubation. the most degenerate cultures did not produce solvents and gave rise to large diffuse colonies that did not contain spor ... | 1987 | 16347466 |
| clostridium acetobutylicum mutants that produce butyraldehyde and altered quantities of solvents. | spontaneous mutants of clostridium acetobutylicum nrrl b643 that were resistant to allyl alcohol (aa) were selected and characterized. these mutants contained 10- to 100-fold reduced activities of butanol and ethanol alcohol dehydrogenase. the aa mutants formed two groups and produced no ethanol. type 1 aa mutants produced significant amounts of a new solvent, butyraldehyde, and contained normal levels of the coenzyme a-dependent butyraldehyde dehydrogenase (bad). type 2 aa mutants produced no s ... | 1987 | 16347493 |
| effect of butanol challenge and temperature on lipid composition and membrane fluidity of butanol-tolerant clostridium acetobutylicum. | the effect of butanol challenge (0, 1.0, 1.5% [vol/vol]) and growth temperature (22, 37, 42 degrees c) on the membrane composition and fluidity of clostridium acetobutylicum atcc 824 and a butanol-tolerant mutant, sa-2, was examined in chemically defined medium. growth of strain atcc 824 into the stationary phase coincided with a gradual increase in the percent saturated to percent unsaturated (su) fatty acid ratio. when challenged with butanol at 22 and 37 degrees c, atcc 824 demonstrated an im ... | 1987 | 16347502 |
| cloning and expression of a clostridium acetobutylicum alcohol dehydrogenase gene in escherichia coli. | an alcohol dehydrogenase (adh) gene from clostridium acetobutylicum was cloned on a recombinant plasmid, pcadh100. escherichia coli hb101, and an allyl alcohol-resistant mutant, hb101-adh1, containing this plasmid were unable to grow aerobically or anaerobically on agar media containing sublethal concentrations of allyl alcohol. e. coli hb101 and hb101-adh1 transformed with the plasmid pcadh100 produced increased levels of ethanol when grown anaerobically under alkaline conditions in the absence ... | 1988 | 16347579 |
| enhancement of butanol formation by clostridium acetobutylicum in the presence of decanol-oleyl alcohol mixed extractants. | extractive fermentation has been proposed to enhance the productivity of fermentations that are end product inhibited. unfortunately, good extractants for butanol, such as decanol, are toxic to clostridium acetobutylicum. the use of mixed extractants, namely, mixtures of toxic and nontoxic coextractants, was proposed to circumvent this toxicity. decanol appeared to inhibit butanol formation by c. acetobutylicum when present in a mixed extractant that also contained oleyl alcohol. however, mainte ... | 1988 | 16347676 |
| stress- and growth phase-associated proteins of clostridium acetobutylicum. | the response of clostridium acetobutylicum atcc 4259 to the stresses produced by a temperature upshift from 28 degrees c to 45 degrees c and by exposure of the organisms to 0.1% n-butanol or to air was examined by analysis of pulse-labeled proteins. the stress response was the induction of the synthesis of a number of proteins, some of which were elicited by the three forms of stress. eleven heat shock proteins were identified by two-dimensional electrophoresis, as were two proteins whose synthe ... | 1988 | 16347709 |
| thiolase from clostridium acetobutylicum atcc 824 and its role in the synthesis of acids and solvents. | thiolase (acetyl-coenzyme a [coa] acetyltransferase, e.c. 2.3.1.19) from clostridium acetobutylicum atcc 824 has been purified 70-fold to homogeneity. unlike the thiolase in clostridium pasteurianum, this thiolase has high relative activity throughout the physiological range of internal ph of 5.5 to 7.0, indicating that change in internal ph during acid production is not an important factor in the regulation of this thiolase. in the condensation direction, the thiolase is inhibited by micromolar ... | 1988 | 16347774 |
| isolation and characterization of mutants of clostridium acetobutylicum atcc 824 deficient in acetoacetyl-coenzyme a:acetate/butyrate:coenzyme a-transferase (ec 2.8.3.9) and in other solvent pathway enzymes. | mutants of clostridium acetobutylicum atcc 824 exhibiting resistance to 2-bromobutyrate or rifampin were isolated after nitrosoguanidine treatment. mutants were screened for solvent production by using an automated alcohol test system. isolates were analyzed for levels of butanol, ethanol, acetone, butyrate, acetate, and acetoin in stationary-phase batch cultures. the specific activities of nadh- and nadph-dependent butanol dehydrogenase and butyraldehyde dehydrogenase as well as those of acetoa ... | 1989 | 16347898 |
| electron spin resonance analysis of the effect of butanol on the membrane fluidity of intact cells of clostridium acetobutylicum. | analysis of electron spin resonance spectra of 5-doxyl stearic acid in aqueous suspensions of clostridium acetobutylicum atcc 824 and the butanol-tolerant sa-2 derivative during a small-scale fermentation at three different butanol challenge levels indicated that the sa-2 strain is able to respond to the physical fluidizing effect of high (1.5%) butanol challenge by reducing its membrane fluidity at 12 and 30 h. the wild-type 824 strain was unable to so respond when challenged at the 1.5% level. | 1989 | 16348040 |
| direct selection of clostridium acetobutylicum fermentation mutants by a proton suicide method. | clostridium acetobutylicum atcc 10132 mutants altered in acetic acid synthesis or in the shift to solventogenesis were directly selected by a proton suicide method after mutagenic treatment, by using bromide and bromate as selective agents. the mutants were characterized according to their solvent and acid production. on the selection plates they differed in colony phenotype from the parent strain. | 1990 | 16348133 |