Relationship between the organic content, heavy metal concentration and anaerobic respiration bacteria in the sediments of Shiwha-ho

Abstract

Anoxic sediments collected from Shiwha-ho area were used to find the relationship between the heavy-metal, organic content and anaerobic respiration bacteria by most probable number (MPN) method. Analysis of the sediments showed that COD content was higher in the sediments collected from Ansan-cheon and Shiwha-ho than those collected from sea area nearby. Particularly noticeable was the fact that heavy metal concentration was much higher in the sediments of Shiwha-ho than those of the other areas. Fe(III)- reducing bacteria were low in the sediments collected from Shiwha-ho area contaminated by heavy-metal, although they were rich in electron donor and electron acceptor for Fe(III)-reducing bacteria. The number of Fe(III)- reducing bacteria using lactate as an electron donor was in the range of 1.1 x 106-4.6 x 107 MPNs/ml in the sediments collected from the sea-side of the lake, which were lower in heavy-metal concentration and higher in Fe-Mn content than those from other region. The number of Fe(III)-reducing bacteria using acetate as an electron donor was in the range of 4.3 x 102-8.1 x 105 MPNs/ml in the same sediments. Chromate-reducing bacteria were more populated (4.6 X 104-8.1 x 105 MPNs/ml) in the sediments contaminated by heavy metals. The number of sulfate-reducing bacteria was 1.49 x 107 MPNs/ml in the sediments with higher COD. Higher sulfate-reducing bacteria were counted in the sediments collected from the more contaminated inner-side than those from the sea-side of the lake.