Characteristics and Activities of Sulfate-Reducing Bacteria

The sulfate-reducing bacteria (SRB) are a unique physiological group of procaryotes because they have the capability of using sulfate as the final electron acceptor in respiration. Initially, these bacteria were treated as biological curiosities and little research effort was devoted to them. An appreciation of the SRB grew, in part, from an interest in understanding their relationship with other life forms. In the last few decades, the metabolic processes of the SRB have received considerable attention, and from these observations it can be concluded that SRB are markedly similar to other bacteria. A hallmark characteristic that distinguishes SRB is the manner in which sulfate is metabolized. With the demonstration that SRB are broadly distributed on earth, it was recognized that these organisms displayed significant roles in nature by virtue of their potential for numerous interactions (Fig. 1). Recent reports have summarized specific life processes mediated by SRB (Postgate, 1984; Fauque et al., 1991; Odom and Singleton, 1993; Barton, 1993; Peck and LeGall, 1994; Widdel and Hansen, 1992). This chapter provides an insight into the basic activities of the SRB, with special reference to biotechnology.