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Aufnahme und Oxidation von Monosacchariden bei Acinetobacter calcoaceticus
Author(s) -
Kleber H.P.,
Haferburg D.,
Asperger O.,
Schmidt M.,
Aurich H.
Publication year - 1984
Publication title -
zeitschrift für allgemeine mikrobiologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0044-2208
DOI - 10.1002/jobm.19840241006
Subject(s) - acinetobacter calcoaceticus , biochemistry , chemistry , monosaccharide , fructose , galactose , cyanide , dehydrogenase , enzyme , acinetobacter , organic chemistry , antibiotics
Acinetobacter calcoaceticus 69‐V is not able to grow on carbohydrates or its derivatives and to use them as sole carbon sources. On the other hand, the partial oxidation of several monosaccharides (glucose, galactose, mannose, xylose, arabinose, ribose) by intact cells has been demonstrated by acid production and measurements of oxygen consumption. Glucose and fructose are taken up by intact cells. Different transport systems exist for the uptake of both hexoses. The “apparent” K M ‐values for the membrane transport amount to 1.5 · 10 −3 and 1.7 · 10 −4 moles/l for glucose and fructose, respectively. Gluconolacton only inhibits the transport of glucose, whereas the transport of both hexoses is inhibited by uranylacetate. Other monosaccharides and metabolic inhibitors are without effect. An exchange of intracellular against extracellular glucose has not been found. Gluconate and CO 2 have been identified as extracellular products of glucose oxidation after an incubation period of more than 5 min, whereas gluconate and 6‐phosphogluconate have been detected as intracellular products. No oxidation products have been found using fructose as substrate. No activity of hexokinase, phosphofructokinase, pyruvate kinase, and 6‐phosphogluconate dehydrogenase have been detected in cell‐free extracts of sonicated cells. An aldose dehydrogenase coupled with an electron transport system occurs in the membrane fraction. The presence of this enzyme was demonstrated by the reduction of dichlorophenolindophenol as well as by oxygen consumption which is inhibited by cyanide. The aldose dehydrogenase exhibits a broad substrate specificity against different aldohexoses and aldopentoses differing by their K M ‐values. Cytochrome b and the terminal oxidase cytochrome o are components of the electron transport system. Neither hydrogen peroxide is formed, nor pyridine nucleotides participate in aldose dehydrogenation.