Growth yields and saturation constant of Desulfovibrio vulgaris in chemostat culture

Abstract

Desulfovibrio vulgaris (strain Marburg) was grown on H2 and sulfate as sole energy source in a chemostat limited by the sulfate supply. The biomass concentration and the sulfate concentration in the culture were determined as a function of the dilution rate. From the data a KS (saturation constant) for sulfate of 10 μM, a μmax of 0.23 h−1, and a \({\text{Y}}_{{\text{SO}}_{\text{4}} ^{2 - } }^{{\text{max}}}\) of 13 g/mol were calculated. The organism was also grown in chemostat culture on H2 and sulfite, H2 and thiosulfate, and pyruvate (without sulfate). \({\text{Y}}_{{\text{SO}}_3 ^{2 - } }^{{\text{max}}}\) was found to be 35 g/mol, \({\text{Y}}_{{\text{S}}_{\text{2}} {\text{O}}_{\text{3}} ^{2 - } }^{{\text{max}}}\) 36 g/mol, and Y pyr max 10 g/mol. The growth yields are discussed with respect to ATP gains in dissimilatory sulfate reduction.