Dissimilatory reduction of selenate and arsenate in nature

By:  and 
Edited by: D.R. Lovley



This chapter discusses the biogeochemical reduction of selenate (Se(VI)) and arsenate (As(V)) when they enter anoxic environments and are used as electron acceptors for the oxidation of organic matter. These reductions are of a dissimilative nature and support the anaerobic growth of selected bacteria which conserve energy from this process. The chapter summarizes what is known about the bacteria's taxonomy, physiology, and biochemistry. Reduction to the solid, relatively unreactive Se(0) represents a mechanism for the removal of toxic Se(VI) and Se(IV) from natural waters. The environmental ramifications of these issues are also discussed in the chapter. The number of bacterial species known to respire selenate and arsenate continues to increase. The biological reduction of selenate and arsenate occurs for a number of reasons. In general, these are assimilation, regulation of reducing equivalents, detoxification, and dissimilation. Each is discussed in detail in the chapter. The realization that arsenate and selenate are indeed suitable electron acceptors and are readily available in both natural and contaminated environments suggests that even more unrelated species will be discovered. The initial biochemical studies also suggest that there may be different pathways for selenate and arsenate reduction, with specific terminal reductases and cytochromes.

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Dissimilatory reduction of selenate and arsenate in nature
Chapter 9
DOI 10.1128/9781555818098.ch9
Year Published 2000
Language English
Publisher ASM
Publisher location Washington, D.C.
Contributing office(s) National Research Program - Western Branch, Toxic Substances Hydrology Program
Description 26 p.
Larger Work Type Book
Larger Work Title Environmental microbe-metal interactions
First page 199
Last page 224