ABSTRACT
The topic of sulfate-reducing bacteria (SRB) in heavy metals bioremediation (or the corollary purpose of metals biorecovery in some environments) has received increased attention over the past couple of decades. Bioremediation, or natural attenuation, by way of harnessing the metabolic activity of SRB to induce the precipitation of contaminant metals as metal sulfides, metal oxides, or elemental metals has become a widely studied and accepted approach to remediating acid-mine drainage and other metalliferous effluents. Yet, a number of factors remain to be understood in better detail for SRB-based bioremediation strategies to be effective. These factors include the nanoparticulate nature of the biogenic precipitates, SRB resistance strategies for metal toxicity and other environmental stressors, community interactions and interdependencies with other microbial species or groups, and the role of organic substrates and natural organic matter in promoting or inhibiting the activity of SRB and influencing metal speciation. This chapter attempts to present a review of seminal and recent studies across these topics and discusses the concept of bacterial sulfate reduction in the context of the evolution and extent of this process within the Earth’s biogeochemical sulfur cycle. In this way, the processes of metal precipitation at human and geological time scales are connected through the environmental and ecological significance of this ancient anaerobic respiratory pathway.
