Abstract

  The aim of the present study was to investigate whether bacterial mutagenicity assays can be applied in sediment quality assessment. The arabinose-sensitive forward mutation strain Salmonella typhimurium BA 9 was added to freshly deposited sediments of the River Elbe, collected during March, April, and May 1994. Up to twelve locations were sampled each month and mutagenicity was determined employing the solid phase and sequentially prepared toluene- and methanol-extracts of the sediments. Mutagenicity was detected at all sites within the solid sediments without addition of S9-mix; however, the addition of mammalian enzymes (59) enhanced the mutagenic effect. In contrast, mutagenicity of toluene extracts containing the lipophilic fraction of the sediment samples was higher in the absence of S9-mix; peaks of mutagenic activity in these samples were observed at Dessau (mouth of the River Mulde) and close to the city of Hamburg (Bunthaus). Similar results were obtained with methanolic extracts of the sediments, although the effects were usually lower in comparison to the corresponding toluene extracts. These results show that the mutagenicity assays are capable of assessing water/sediment contamination and reveal that the mutagenicity detected in sediments reflects local industrial activities as well as hydrologic conditions.

Keywords: arabinose resistance, mutation assays, River Elbe, Salmonella typhimurium, seasonal                  aspects, sediment