Growth kinetics of Acetobacterium sp. on methanol-formate in continuous culture

摘要

The fermentative metabolism of Acetobacterium sp. grown on methanol-formate in continuous culture is described. The reaction stoichiometry of methanol-formate, including cells, were as follows: CH_3OH + 1.13HCOOH -> 0.87CH_3COOH + 0.47 cell C. Formate enhanced growth yields by approximately 60% compared with methanol-CO_2-grown cultures. Comparison of yields on methanol-formate allowed calculation of an energy yield of 1.3 mol ATP per mol acetate formed during homoacetate fermentation. The magnitudes of Y_(EG), the theoretical maximum yield of Y_E, and m, the maintenance coefficient, were determined by growing the organism in methanol-formate and resulted in 16.5 g cell (mol methanol catabolized)~(-1) and 0.674 mmol methanol catabolized (g cell)~(-1) h~(-1), respectively. It is concluded that formate might replace CO_2 as a source of carboxyl donor.