Energetic aspects of the metabolism of reduced sulphur compounds in Thiobacillus dentrificans.
Yields of Thiobacillus dentrificans on different substrates were compared. The organism was grown in a chemostat at a dilution rate of 0.03 h-1. From the difference in the cell yields with (1) oxygen (6.40 g carbon per mole thiosulphate) and (2) nitrate (4.51 g carbon per mole thiosulphate) as an electron acceptor the experimental value for Y ATP was estimated to be 1.75. The efficiency of the biosynthetic system would be 42% if 1 ATP should be needed in reversed electron transport, and 57% if this was 2 ATP per electron pair. It could be calculated that during anaerobic oxidation of thiosulphate with nitrate 1.41 or 1.16 ATP per 2 electrons are generated if 1 or 2 ATP respectively per thiosulphate is formed in substrate-level phosphorylation. For aerobic oxidation these figures are 2.40 and 2.16, respectively.
D000332:Aerobiosis; D000693:Anaerobiosis; D004579:Electron Transport; D004734:Energy Metabolism; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010101:Oxygen Consumption; D013440:Sulfides / Q000378:metabolism*; D013447:Sulfites / Q000378:metabolism; D013855:Thiobacillus / Q000254:growth & development / Q000378:metabolism*; D013885:Thiosulfates / Q000378:metabolism
D009566:Nitrates; D009573:Nitrites; D013440:Sulfides; D013447:Sulfites; D013885:Thiosulfates