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At least 235 records · Page 13Linked to original sources
PubMed1980

Influence of growth phase and carbon source on the content of rubredoxin in Acinetobacter calcoaceticus.

The rubredoxin content of Acinetobacter calcoaceticus in dependence on the carbon source (acetate, n-alkanes, succinate, L-malate) and on the growth phase was studied by means of a radioimmunoassay. The method used was specific for rubredoxin and Acinetobacter calcoaceticus. The formation of rubredoxin increased with time up to the end of the logarithmic phase when n-alkanes were the sole carbon source. After growth of Acinetobacter calcoaceticus on non-hydrocarbon substrates, rubredoxin was not detected.

Acinetobacter↗
PubMed1995

Carbon source nutrition of rapamycin biosynthesis in Streptomyces hygroscopicus.

Chemically-defined media were developed for rapamycin production by Streptomyces hygroscopicus. Thirty-five carbon sources were tested for their effect on production. Eight failed to support growth and seven appeared to repress or inhibit rapamycin formation. The best combination of two carbon sources were 2% fructose and 0.5% mannose. Acetate and propionate, which are known to contribute most of the carbon atoms of the lactone ring, were unsatisfactory for growth and/or rapamycin production.

Antibiotics, Antineoplastic↗
PubMed1997

Ca2+/calmodulin-binding proteins in yeast. Catabolite repression and induction by carbon sources.

Soluble calmodulin-binding proteins from Saccharomyces carlsbergensis were analyzed in cells grown on glucose, maltose and galactose as carbon source. A large number of polypeptide chains showed affinity for calmodulin by affinity chromatography and overlay techniques. Amongst these, polypeptides of 115, 67 and 45 kDa were only detected during the second exponential phase of growth on glucose or non-fermentative carbon sources, suggesting that they might be subjected to catabolite repression. Polypeptides of 195 and 22 kDa were only observed in cells grown on maltose, whereas 88 kDa polypeptide was only observed in galactose-grown cells. Among the calmodulin -binding polypeptides, eight were phosphorylated in a Ca2+/calmodulin -dependent manner (220, 200, 175, 100, 62, 55, 31 and 16 kDa). Ca2+/calmodulin dependent [gamma-32P] incorporation was dramatically decreased in yeast cells submitted to a heat treatment.

Calmodulin↗
PubMed2003

A requirement for anaerobically induced redox functions during aerobic growth of Escherichia coli with serine, glycine and leucine as carbon source.

Escherichia coli strains with mutations in 3 genes coding for redox functions--torA, nuoM and glpC--are able to grow with pyruvate as carbon source, but are not able to use a combination of serine, glycine and leucine as carbon source, unlike the parent strain which uses either. All three mutants are able to produce and activate L-serine deaminase (L-SD) when grown in glucose minimal medium, and thus should be able to convert serine to pyruvate and grow on it. We suggest that activation of L-SD involves specific chemical reactions, perhaps building an Fe-S cluster. Mutant cells can carry out the necessary reaction to activate L-SD when grown in glucose minimal medium but apparently cannot do so when grown in SGL medium.

Anaerobiosis↗
PubMed2000

Quantitative determination of metabolic fluxes during coutilization of two carbon sources: comparative analyses with Corynebacterium glutamicum during growth on acetate and/or glucose.

Growth of Corynebacterium glutamicum on mixtures of the carbon sources glucose and acetate is shown to be distinct from growth on either substrate alone. The organism showed nondiauxic growth on media containing acetate-glucose mixtures and simultaneously metabolized these substrates. Compared to those for growth on acetate or glucose alone, the consumption rates of the individual substrates were reduced during acetate-glucose cometabolism, resulting in similar total carbon consumption rates for the three conditions. By (13)C-labeling experiments with subsequent nuclear magnetic resonance analyses in combination with metabolite balancing, the in vivo activities for pathways or single enzymes in the central metabolism of C. glutamicum were quantified for growth on acetate, on glucose, and on both carbon sources. The activity of the citric acid cycle was high on acetate, intermediate on acetate plus glucose, and low on glucose, corresponding to in vivo activities of citrate synthase of 413, 219, and 111 nmol. (mg of protein)(-1). min(-1), respectively. The citric acid cycle was replenished by carboxylation of phosphoenolpyruvate (PEP) and/or pyruvate (30 nmol. [mg of protein](-1). min(-1)) during growth on glucose. Although levels of PEP carboxylase and pyruvate carboxylase during growth on acetate were similar to those for growth on glucose, anaplerosis occurred solely by the glyoxylate cycle (99 nmol. [mg of protein](-1). min(-1)). Surprisingly, the anaplerotic function was fulfilled completely by the glyoxylate cycle (50 nmol. [mg of protein](-1). min(-1)) on glucose plus acetate also. Consistent with the predictions deduced from the metabolic flux analyses, a glyoxylate cycle-deficient mutant of C. glutamicum, constructed by targeted deletion of the isocitrate lyase and malate synthase genes, exhibited impaired growth on acetate-glucose mixtures.

Acetates↗
PubMed2001

Nutrient removal with methanol as a carbon source full-scale continuous inflow SBR application.

Methanol was applied to a full-scale continuous inflow SBR, as a carbon source for denitrification and possible phosphorus removal. This research was conducted at the District of Kent Wastewater Treatment Plant in Agassiz, British Columbia, Canada. This plant employs two SBR's working in parallel; one unit was used as a control, without the addition of methanol. There was no difference in the overall total nitrogen removal efficiency through methanol addition, however,the additional carbon source significantly shortened the denitrification reaction time in the existing reactor. The high nitrogen removal efficiency, with or without methanol addition, was primarily due to the advantages provided by continuous-flow SBR carbon loading. The phosphorus removal efficiency in the experimental SBR was also consistently higher than in the control SBR. The solids production from methanol addition wa s estimated to vary between 0.18 and 0.29gVSS/gCH3OH. Methanol addition also had an influence on the settling qualities of the sludge.

Carbon↗
PubMed2006

Energy metabolism of trypanosomatids: adaptation to available carbon sources.

Some development stages of the trypanosomatid protozoan parasites are well adapted to in vitro culture. They can be maintained in rich medium containing large excess of glucose and amino acids, which they use as carbon sources for ATP production. Under these growth conditions, carbon sources are converted into partially oxidized end products by so-called aerobic fermentation. Surprisingly, some species, such as the Trypanosoma brucei, Trypanosoma cruzi and Crithidia insect stages, prefer consuming glucose to amino acids, although their natural habitat is L-proline-rich. This review focuses on recent progress in understanding glucose and l-proline metabolism of insect stages, how these metabolic processes are regulated, and the rationale of the aerobic fermentation strategies developed by these parasites.

Adaptation, Physiological↗
PubMed2005

Utilization of glycerol as carbon source on the growth, pigment and lipid production in Spirulina platensis.

The ability of the cyanobacterium Spirulina platensis to utilize glycerol as the carbon source was investigated. In this work, we report on some physiological parameters that characterize the adaptive response of Spirulina platensis for the utilization of glycerol as the carbon source. A marked decrease was observed in the pigments Chlorophyll a (Chl a) and phycocyanin content of Spirulina platensis grown on glycerol medium when compared to the control. The lipid content in the glycerol-grown groups was comparable with the control, but variations were observed in the fatty acid profile of the total lipid mainly in the level of monoenes and polyenes. There was an increase in the gamma-linolenic acid (GLA) in the Neutral lipid (NL) fraction.

Bacterial Proteins↗
PubMed2002

Metabolic improvements and use of inexpensive carbon sources in microbial production of polyhydroxyalkanoates.

This paper deals with the microbial production of polyhydroxyalkanoates (PHAs), biodegradable thermoplastics which perform excellently as a material, from inexpensive renewable carbon sources. To date, with the help of genetic engineering techniques, it has become possible to design several types of PHAs with different compositions and to enhance the productivities of PHAs. In addition, molecular breeding of PHA biosynthesis enzymes has been demonstrated to improve polymer production. Mutant PHA synthases generated by an in vitro evolution technique have allowed the enhanced production and quality alteration of PHAs. Furthermore, use of inexpensive renewable carbon sources, such as plant oils, waste materials, and carbon dioxide, would be a key for a reduction in PHA production cost.

Journal Article↗
PubMed2001

Non-repressing carbon sources for alcohol oxidase (AOX1) promoter of Pichia pastoris.

The growth of Pichia pastoris in a mixture of either glycerol or glucose and methanol follows a diauxic growth, with C1 utilizing enzymes being repressed. Therefore, these carbon sources can not be used as a mixture with methanol to simultaneously grow P. pastoris and induce C1 utilizing enzymes, especially in a shake flask cultures of AOX-deficient P. pastoris. Among the alternative carbon sources tested, alanine, sorbitol, mannitol and trehalose, did not repress beta-gal production when methanol was used as an inducer in mut- strain of P. pastoris. Our results show that either one of alanine, sorbitol, mannitol or trehalose can be used as a sole carbon and energy source for P. pastoris, although the doubling time on trehalose was very long. Mut- strains growing in media containing trehalose, alanine, sorbitol and mannitol with methanol (0.5%) as an inducing agent expressed as much or higher amount of beta-gal as compared to the mut+ growing in methanol containing media.

Journal Article↗
PubMedDate not supplied

Enhancement of biodegradation of phenol and a nongrowth substrate 4-chlorophenol by medium augmentation with conventional carbon sources.

The enhancement of biodegradation of phenol and 4-chlorophenol (4-cp) as a cometabolised compound by Pseudomonas putida ATCC 49451 was accomplished by augmenting the medium with conventional carbon sources such as sodium glutamate and glucose. Compared with phenol as the sole carbon source, the addition of 1 gl(-1) sodium glutamate increased the toxicity tolerance of cells toward 4-cp and significantly improved the biodegradation rates of both phenol and 4-cp even when the initial concentration of 4-cp was as high as 200 mgl(-1). On the other hand, supplementation of glucose caused a significant drop in the medium pH from 7.2 to 4.3 resulting in a reduction of degradation rate, leaving a considerable amount of 4-cp undegraded when the initial concentration of 4-cp was higher than 100 mgl(-1). By regulating the pH of the medium, however, enhancement of degradation rates of phenol and 4-cp in the presence of glucose was achieved with a concomitant complete degradation of phenol and 4-cp.

Biodegradation, Environmental↗
PubMed1989

3-nitrobenzenesulfonate, 3-aminobenzenesulfonate, and 4-aminobenzenesulfonate as sole carbon sources for bacteria.

Aerobic, carbon-limited, enrichment cultures containing 3-aminobenzenesulfonate or 3-nitrobenzenesulfonate as the sole source of carbon and energy yielded growth and complete substrate disappearance. Pure cultures of putative pseudomonads were isolated which utilized these compounds quantitatively. Degradation was compared with that of 2- and 4-aminobenzenesulfonate.

Journal Article↗
PubMed1998

The influence of carbon source on the level and composition of ceramides of the Candida lipolytica yeast.

Candida lipolytica yeast was grown batchwise on two different carbon sources, glucose and n-hexadecane. Free ceramides were quantitatively isolated from sphingolipid fractions of total lipids by a combination of column chromatography and preparative thin-layer chromatography. Their composition, after acid methanolysis, was analysed by gas-liquid chromatography. The ceramide content accounted for 2.6% of the total cell lipids in hexadecane-grown cells, which was 1.5 times higher than in glucose-grown cells. The fatty acid composition of ceramides was characterized by the predominance of fatty acids shorter than 20 carbon atoms and by high concentrations of fatty acids with 16 carbon atoms after growth on both carbon sources. The dominant fatty acid was hydroxylated 16:0 in the glucose-grown cells and 16:0 in the hexadecane-grown cells. The striking finding was the low degree of fatty acid hydroxylation and relatively high proportion of odd-numbered fatty acids in ceramide of the n-hexadecane-grown cells. The ceramides contained an unusual long-chain base composition. In hexadecane-grown cells more than 60% of the long-chain bases were C19 phytosphingosine. In glucose-grown cells more than one-half of the total long-chain bases were tetrahydroxy bases, 4,5-dihydroxysphinganine and 4,5-dihydroxyeicosasphinganine.

Alkanes↗
PubMed1986

Electron transfer flavoprotein from Methylophilus methylotrophus: properties, comparison with other electron transfer flavoproteins, and regulation of expression by carbon source.

When grown on methylated amines as a carbon source, Methylophilus methylotrophus synthesizes an electron transfer flavoprotein (ETF) which is the natural electron acceptor of trimethylamine dehydrogenase. It is composed of two dissimilar subunits of 38,000 and 42,000 daltons and 1 mol of flavin adenine dinucleotide. It was reduced by trimethylamine dehydrogenase to a stable anionic semiquinone form, which could not be converted, either enzymatically or chemically, to the fully reduced dihydroquinone. This ETF exhibited spectral properties which were nearly identical to ETFs from bacterium W3A1, Paracoccus denitrificans, and pig liver mitochondria. M. methylotrophus ETF cross-reacted immunologically and enzymatically with the ETF of bacterium W3A1 but not with the other two ETFs. In M. methylotrophus and bacterium W3A1, ETF and trimethylamine dehydrogenase were each expressed during growth on trimethylamine and were each absent during growth on methanol.

Animals↗
PubMed2000

Production of polyesters consisting of medium chain length 3-hydroxyalkanoic acids by Pseudomonas mendocina 0806 from various carbon sources.

Pseudomonas mendocina strain 0806 was isolated from oil-contaminated soil and found to produce polyesters consisting of medium chain length 3-hydroxyalkanoates (mclPHAs). The monomers of mclPHAs contained even numbers of carbon atoms, such as 3-hydroxyhexanoate (HHx or C6), 3-hydroxyoctanoate (HO or C8), and/or 3-hydroxydecanoate (HD or C10) as major components when grown on many carbon sources unrelated to their monomeric structures, such as glucose, citric acid, and carbon sources related to their monomeric structures, such as myristic acid, octanoate, or oleic acid. On the other hand, PHA containing both even and odd numbers of hydroxyalkanoates (HA) monomers was synthesized when the strain was grown on tridecanoic acid. The molar ratio of carbon to nitrogen (C/N) had a significant effect on PHA composition: the strain produced PHAs containing 97-99% of HD monomer when grown in a glucose ammonium sulfate medium of C/N<20, and 20% HO, and 80% of the HD monomer when growth was conducted in media containing C/N>40. It was demonstrated that the HO/HD ratio in the polymers remained constant in media with a constant C/N ratio, regardless of the glucose concentration. Up to 3.6 g/L cell dry weight containing 45% of PHAs was produced when the strain was grown for 48 h in a medium containing 20 g/L glucose with a C/N ratio of 40.

Glucose↗
PubMed2005

[Bioflocculant producing capability by two strains of Bacillus sp. in diversified carbon sources].

Two strains of Bacillus sp. F2 and F6 could produce bioflocculants with high flocculating effects by pure culture and mixed culture. Many kinds of carbon sources could be utilized. Organic compound which molecular weight under 200 such as saccharide, alcoholic aldehyde, ester and organic acid were favorable for producing bioflocculant. And some low-cost biomass scrap could be used as good carbon sources for industrialized production of bioflocculants, such as waste beet molasses, cellulose's fermentation residue and sewage of hydrogen producing reactor.

Bacillus↗
PubMed2005

Effect of different carbon sources on endochitinase production by Colletotrichum gloeosporioides.

The present work analyzes the production of endochitinase by Colletotrichum gloeosporioides, a phytopathogenic fungus, using six different carbon sources and two pH values. For quantitative assay of endochitinase activity in solution, the synthetic substrate 4-methylumbelliferyl-beta-D-N,N',N"-triacetylchitotrioside was used. The major productions were obtained at pH 7.0 and 9.0, when colloidal chitin and glucose were used, whereas xylose and lactose were not good carbon sources. When testing different concentrations of colloidal chitin, glucose and glucosamine, colloidal chitin 0.5% was the best substrate, giving values of 2.4 U at the fifth day. When using glucose, best production occurred at 0.3% concentration, after 5 days growth, with values of 1.31 U. Endochitinase production was markedly decreased in high levels of glucose and in all glucosamine concentrations tested. SDS-PAGE co-polymerized with glycol-chitin analysis showed three major activity bands of 200, 100, and 95 kDa, when incubated at 50 degrees C.

Carbon↗
PubMed2004

Quantifying carbon sources for de novo lipogenesis in wild-type and IRS-1 knockout brown adipocytes.

Studies were conducted to evaluate the flux of various carbon sources to lipogenesis during brown adipocyte differentiation. (13)C labeling and isotopomer spectral analysis quantified the contribution of metabolites to de novo lipogenesis in wild-type (WT) and insulin receptor substrate-1 knockout (KO) brown adipocytes. Both glucose (Glc) and glutamine (Gln) provided substantial fractions of the lipogenic acetyl CoA for both WT and KO cells in standard media, together contributing 60%. Adding acetoacetate (AcAc; 10 mM) to the medium resulted in a large flux of AcAc to lipid, representing 70% of the lipogenic acetyl CoA and decreasing the contribution of Glc plus Gln to 30%. For WT cells, the fractional synthesis of new fatty acids during 4 days of differentiation was 80% of the total. Similarly, 80% of the lipidic glycerol was derived from Glc in the medium; Gln was not a precursor for glycerol. When Gln was removed from the medium, the contribution of Glc to fatty acid synthesis doubled, replacing most of the contribution of Gln and maintaining total lipogenesis. Conversely, removal of Glc dramatically decreased lipogenesis. These results indicate that Glc's distinct role in lipid synthesis during differentiation cannot be replaced by other carbon sources, consistent with the role of Glc supplying NADPH and/or glycerol for triglyceride synthesis.

Acetoacetates↗