[Carbon and sulfur metabolism in representatives of two clusters of bacteria of the genus Leucothrix: a comparative study].
Major pathways of carbon and sulfur metabolisms were studied in representatives of two clusters of bacteria: Leucothrix thiophila (cluster I, strains 2WS, 4WS, and 6WS) and Leucothrix sp. (cluster II, strains 1WS, 3WS, and 5WS). All strains were capable of chemoorganoheterotrophic growth, as well as of chemolithoheterotrophic growth in the presence of reduced sulfur compounds. The bacteria were found to possess a complete set of the enzymes of the tricarboxylic acid cycle and glyoxylate cycle. The hydrogenase activity in cells of cluster I strains was an order of magnitude lower than in cluster II strains and in other known heterotrophic bacteria. Cells of bacteria of both clusters exhibited high activity levels of enzymes involved in the energy metabolism of sulfur. The oxidation of sulfur compounds and the operation of the electron-transport chain were shown to be related. Cluster II bacteria more efficiently use organic compounds in their energy metabolism, whereas cluster I bacteria are characterized by more efficient utilization of reduced sulfur compounds. During sulfite oxidation, cluster I bacteria can synthesize ATP both via substrate-level phosphorylation and oxidative phosphorylation, whereas cluster II bacteria synthesize ATP only via the latter process.
Voronezh State University, Voronezh, 394893 Russia.
M Iu
MIu
Grabovich
N M
NM
Dul'tseva
G A
GA
Dubinina
D000255:Adenosine Triphosphate / Q000096:biosynthesis / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D002952:Citric Acid Cycle; D006038:Glyoxylates / Q000378:metabolism; D006864:Hydrogenase / Q000378:metabolism; D010084:Oxidation-Reduction; D013455:Sulfur / Q000378:metabolism*; D013457:Sulfur Compounds / Q000378:metabolism; D041962:Thiotrichaceae / Q000378:metabolism
D006038:Glyoxylates; D013457:Sulfur Compounds; D013455:Sulfur; D002244:Carbon; D000255:Adenosine Triphosphate; D006864:Hydrogenase; C031150:glyoxylic acid