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  • Polymer and Materials Science  (4)
  • Acetyl-phosphate  (1)
  • 1
    ISSN: 1432-072X
    Keywords: Key wordsCorynebacterium glutamicum ; Acetate ; metabolism ; Acetate kinase ; Phosphotransacetylase ; Isocitrate lyase ; Malate synthase ; Acetyl-CoA ; Acetyl-phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the amino-acid-producing microorganism Corynebacterium glutamicum, the specific activities of the acetate-activating enzymes acetate kinase and phosphotransacetylase and those of the glyoxylate cycle enzymes isocitrate lyase and malate synthase were found to be high when the cells were grown on acetate (0.8, 2.9, 2.1, and 1.8 U/mg protein, respectively). When the cells were grown on glucose or on other carbon sources such as lactate, succinate, or glutamate, the specific activities were two- to fourfold (acetate kinase and phosphotransacetylase) and 45- to 100-fold (isocitrate lyase and malate synthase) lower, indicating that the synthesis of the four enzymes is regulated by acetate in the growth medium. A comparative Northern (RNA) analysis of the C. glutamicum isocitrate lyase and malate synthase genes (aceA and aceB) and transcriptional cat fusion experiments revealed that aceA and aceB are transcribed as 1.6- and 2.7-kb monocistronic messages, respectively, and that the regulation of isocitrate lyase and malate synthase synthesis is exerted at the level of transcription from the respective promoters. Surprisingly, C. glutamicum mutants defective in either acetate kinase or phosphotransacetylase showed low specific activities of the other three enzymes (phosphotransacetylase, isocitrate lyase, and malate synthase or acetate kinase, isocitrate lyase, and malate synthase, respectively) irrespective of the presence or absence of acetate in the medium. This result and a correlation of a high intracellular acetyl coenzyme A concentration with high specific activities of isocitrate lyase, malate synthase, acetate kinase, and phosphotransacetylase suggest that acetyl coenzyme A or a derivative thereof may be a physiological trigger for the genetic regulation of enzymes involved in acetate metabolism of C. glutamicum.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 59 (1987), S. 695-700 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Ethanol production with bacteria. Strains of Saccharomyces cerevisiae have mostly been used for the production of ethanol from sugar by yeasts. Recently it was shown that the bacterium Zymomonas mobilis has some advantages compared to yeast for the production of industrial alcohol. Compared to traditional yeast fermentation, ethanol yield is about 5% higher than with yeast, since less sugar is incorporated into cell material by this bacterium. Like yeast, Zymomonas mobilis has remarkably high ethanol tolerance which enables the bacterium to produce ethanol concentrations of more than 13 vol.-% from sugar solutions of appropriate concentration. Investigations of the spectrum of lipids present have shown that this bacterium contains large quantities of hopanoids which are presumably of significance for the stabilization of cell membranes in the presence of ethanol. Since the cost of the sugar greatly influences the profitability fraction formed in the production of glucose syrup from wheat flour was investigated. It was shown that after enzymatic saccharification of this waste starch the glucose was efficiently fermented to ethanol by Zymomonas mobilis. It is planned to broaden the substrate spectrum of Zymomonas mobilis by gene cloning techniques so that in future pentoses, e. g. xylose or arabinose, can also be fermented to ethanol by this organism.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 63 (1991), S. 1238-1240 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 53 (1981), S. 854-863 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Description / Table of Contents: Biology of methane formation. It has long been known that methane is produced in nature where organic compounds are degraded by microorganisms under anaerobic conditions. On an industrial scale, this process has been used for more than 50 years in the stabilization of sewage sludge from municipal waste water treatment plants. Recently it could be demonstrated that at least three different groups of bacteria are involved in the degradation of organic material into methane and CO2. Hydrolytic and fermentative bacteria first degrade the organic compounds into various alcohols, fatty acids, hydrogen and CO2. The second group of bacteria convert these metabolites into acetic acid, hydrogen, and CO2, which are then utilized by the methanogenic bacteria to produce methane and CO2.
    Notes: Es ist seit langem bekannt, daß überall in der Natur, wo organisches Material unter anaeroben Bedingungen mikrobiell abgebaut wird, Methan entsteht. Diese Fähigkeit anaerober Bakterien, organische Substanzen zu Methan und Kohlendioxid abzubauen, wird im großtechnischen Maßstab seit über 50 Jahren zur Stabilisierung von Klärschlamm genutzt. In jüngster Zeit konnte nachgewiesen werden, daß bei diesem Prozeß mindestens drei verschiedene Gruppen von Bakterien beteiligt sind. Bei dieser Abbau- bzw. Nahrungskette werden zunächst die verschiedenen organischen Verbindungen zu niedrigen Alkoholen, Fettsäuren, Wasserstoff und Kohlendioxid von einer Bakteriengruppe abgebaut. Die zweite Mikroorganismen-Gruppe setzt diese Alkohole, Säuren etc. weiter zu Essigsäure, Wasserstoff und Kohlendioxid um, welche dann von den Methan-Bakterien als Substrat verwertet und in Methan und Kohlendioxid (Biogas) umgewandelt werden.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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