Isolation, Characterization and Growth Control of a Sulfate Reducing Bacteria from Sewage Water

Sulfate Reducing Bacteria (SRB) are a diverse heterogeneous group of anaerobic microorganisms inhabiting in various environmental conditions. SRB are one of the most important groups of microorganisms that participate in various nutritional cycles of the environment and cause degradation of various organic matters through the process of dissimilatory sulfate reduction. They are known to be implicated in cases of microbially influenced corrosion arising in a wide range of natural and industrial circumstances. SRB are known to utilize the indigenous sulfate source and hence produce the deadly poisonous hydrogen sulfide (H2S) gas. In the present study one strain of SRB designated as WS-1 was collected from sewage water. The sample was enriched in a basal mineral media in an anaerobic condition using lactic acid as carbon source. The isolated strain (WS-1) was Gram negative cocci shaped and occured in chains and pairs. Biochemical characterization of the strains revealed that, the strain WS-1 was closely related to Veillonella. Sulfate reduction and sulfide formation were evident both in case of lactic acid and acetic acid as carbon source. It was observed that sodium nitrate and potassium nitrate were effective in controlling sulfide formation.