Sulfate reducing potential in an estuarine beach

Abstract

Sulfate reducing bacteria (SRB) and their activity (SRA) together with total anaerobic and aerobic bacterial flora were estimated during July 1982-April 1983 and July-August 1984 from 1, 3 and 5 cm depths using core samples. The average number (no. g^-1) of SRB in these depths was 1.27 x 10², 2.01 x 10² and 2.36 x 10² respectively. The averages of ratio of aerobic flora to SRB were 87.6, 61.4 and 27.6 and the anaerobic to the SRB were 3.1, 1.7 and 0.92 at 1, 3 and 5 cm depths respectively. SRA determined in liquid medium using serially diluted sediment ranged from 0.04 at 1 cm depth to 1.02 MS^2- .g^-1 24h^-1 at 3 cm. SRA determined directly using sediment slurries showed values up to 0.99 <i>µM</i>.g^-1 24h^-1 at 5 cm depth. Sodium molybdate at 20 m<i>M</i> concentration did not inhibit sulfate reduction.