The distribution and activity of sulphate reducing bacteria in estuarine and coastal marine sediments

Sulphate-reducing bacteria (SRB) play a vital role both the carbon and sulphur cycles and thus are extremely important components of the global microbial community. However, it is clear that the ecology, the distribution and activity of different SRB groups is poorly understood. Probing of rRNA suggests that different sediments have distinctly different patterns of SRB with complex factors controlling the activity of these organisms. The linking of community structure and function using sediment slurry microcosms suggests that certain groups of SRB, e.g., Desulfobacter and Desulfobulbus, can be linked to the use of specific substrates in situ. However, it is still unclear what environmental substrates are utilised by the majority of known SRBs. The work to date has greatly enhanced our understanding of the ecology of these organisms and is beginning to suggest patterns in their distribution and activity that may be relevant to understanding microbial ecology in general.