ABSTRACT
84Sulfate reducing bacteria in marine sediment mainly utilize sulfate as a terminal electron acceptor with different organic compounds as electron donor. This study investigated microbial sulfate reducing activity of coastal sediment from the Marine Lake Grevelingen (the Netherlands) using different electron donors and electron acceptors. All four electron donors (ethanol, lactate, acetate and methane) showed sulfate reducing activity with sulfate as electron acceptor, suggesting the presence of an active sulfate reducing bacterial population in the sediment, even at dissolved sulfide concentrations exceeding 12 mM. Ethanol showed the highest sulfate reduction rate of 55 μmol gvss−1 d−1 compared to lactate (32 μmol gvss−1 d−1), acetate (26 μmol gvss−1 d−1) and methane (4.7 μmol gvss−1 d−1). Sulfate reduction using thiosulfate and elemental sulfur as electron acceptors and methane as the electron donor was observed, however, mainly by disproportionation rather than by anaerobic oxidation of methane coupled to sulfate reduction. This study showed that the Marine Lake Grevelingen sediment is capable to perform sulfate reduction by using diverse electron donors, including the gaseous and cheap electron donor methane.
