Growth yields and growth rates of Desulfovibrio vulgaris (Marburg) growing on hydrogen plus sulfate and hydrogen plus thiosulfate as the sole energy sources.

Abstract

Desulfovibrio vulgaris (Marburg) was grown on H2 plus sulfate and H2 plus thiosulfate as the sole energy sources and acetate plus CO2 as the sole carbon sources. Conditions are described under which the bacteria grew exponentially. Specific growth rates (μ) and molar growth yields (Y) at different pH were determined. μ and Y were found to be strongly dependent on the pH. Highest growth rates and molar growth yields were observed for growth on H2 plus sulfate at pH 6.5 (μ=0.15h-1; Y SO 4 2- =8.3g·mol-1) and for growth on H2 plus thiosulfate at pH 6.8 (μ=0.21h-1; Y S 2O 3 2 =16.9g·mol-1). The growth yields were found to increase with increasing growth rates: plots of 1/Y versus 1/μ were linear. Via extrapolation to infinite growth rates a Y SO4 2- /max of 12.2g·mol-1 and a YS2O 3 2- /max of 33.5g·mol-1 was obtained. The growth yield data are interpred to indicate that dissimilatory sulfate reduction to sulfide is associated with a net synthesis of 1 mol of ATP and that near to 3 mol of ATP are formed during dissimilatory sulfite reduction to sulfide.