Substrates for Sulfate Reduction and Methane Production in Intertidal Sediments

AUTOR(ES)

Winfrey, Michael R.

RESUMO

The activity of and potential substrates for methane-producing bacteria and sulfate-reducing bacteria were examined in marsh, estuary, and beach intertidal sediments. Slow rates of methane production were detected in all sediments, although rates of sulfate reduction were 100- to 1,000-fold higher. After sulfate was depleted in sediments, the rates of methane production sharply increased. The addition of methylamine stimulated methanogenesis in the presence of sulfate, and [14C]methylamine was rapidly converted to 14CH4 and 14CO2 in freshly collected marsh sediment. Acetate, hydrogen, or methionine additions did not stimulate methanogenesis. [methyl-14C]methionine and [2-14C]acetate were converted to 14CO2 and not to 14CH4 in fresh sediment. No reduction of 14CO2 to 14CH4 occurred in fresh sediment. Molybdate, an inhibitor of sulfate reduction, inhibited [2-14C]acetate metabolism by 98.5%. Fluoracetate, an inhibitor of acetate metabolism, inhibited sulfate reduction by 61%. These results suggest that acetate is a major electron donor for sulfate reduction in marine sediments. In the presence of high concentrations of sulfate, methane may be derived from novel substrates such as methylamine.

Documentos Relacionados

• Competitive Mechanisms for Inhibition of Sulfate Reduction and Methane Production in the Zone of Ferric Iron Reduction in Sediments
• Methanogenesis and Sulfate Reduction: Competitive and Noncompetitive Substrates in Estuarine Sediments
• Dynamics of Methane Production, Sulfate Reduction, and Denitrification in a Permanently Waterlogged Alder Swamp
• Effects of Temperature and Pressure on Sulfate Reduction and Anaerobic Oxidation of Methane in Hydrothermal Sediments of Guaymas Basin†
• Competition for Sulfate and Ethanol Among Desulfobacter, Desulfobulbus, and Desulfovibrio Species Isolated from Intertidal Sediments