pH Auxostat continuous culture of Acetobacterium sp. coupled with removal of acetate by Methanosaeta concilii

A novel continuous culture system of Acetobacterium sp. coupled with a fixed-bed reactor of Methanosaeta concilii is described. With methanol (250 mmol l(-1)) plus CO2 at D = 0.02 h(-1), the productivities of vitamin B-12 and cells were 1.2 mg l(-1).d and 0.31 g l(-1)d(-1), respectively, with 83% methanol consumption. With methanol (250 mmol l(-1))-formate (150 mmol l(-1)), however, these productivities increased ca. 2.7-fold, respectively at the same D, with complete consumption of methanol. At D = 0.15 h(-1) with these latter substrates, these productivities enhanced ca. 14-fold, that is, 17 mg l(-1).d and 4.3 g l(-1).d, respectively, with 51% methanol consumption.