Effect of sulphate concentration on the community structure and activity of sulphate reducing bacteria

Oyekola, Oluwaseun O; van Hille, Rob; Harrison, Susan T L

Effect of sulphate concentration on the community structure and activity of sulphate reducing bacteria

Journal Article

2007

Journal Title

Advanced Materials Research

Link to Journal

http://www.scientific.net/AMR

Publisher

Trans Tech Publications

Publisher

University of Cape Town

Abstract

This study investigated the effect of sulphate concentration and residence time on the performance of anaerobic sulphate reduction by a mixed sulphate reducing bacteria (SRB) culture using lactate as the sole carbon source and electron donor. The process perforrnance is related to the population structure of the microbial consortia and dominant metabolic reactions. Laboratory scale chemostat cultures at different residence times (1-4 d) and sulphate concentrations (1.0-10.0 glL) were employed. Lactate oxidation was prevalent at feed sulphate concentrations of 1.0 to 5.0 glL. A colresponding increase in the volumetric sulphate reduction rate with increasing volumetric loading rate was also observed at this range. However, at the higher feed sulphate concentration range (10.0-15.0 glL), sulphate inhibition, lactate fermentation and an increased microbial diversity were evident. At each feed concentration of sulphate in the range 5.0 to 15.0 glL, varying dilution rates resulted in significant shifts in dominant metabolic reactions. Sulphate concentration and residence time have significant effects on both the structure of the microbial population and kinetics of biological sulphate reduction.