SpeciesBenzene Oxidation by Geobacter

nderstanding the mechanisms for anaerobic benzene degra-dationmaygreatlyaidthedesignandoptimizationofstrate-gies for the bioremediation of subsurface environments contam-inated with petroleum and is expected to reveal novelbiochemistry for enzymatic attack on this highly stable molecule(9, 12, 20, 36, 38, 62). Monoaromatic hydrocarbons are often thepetroleum contaminants of the greatest concern in groundwaterbecauseoftheirwatersolubility,andbenzeneisthemosttoxicofthese contaminants (11). Aerobic benzene-degrading organismsare ubiquitous, and their degradation pathway and methods todetectthemarewellestablished(21,30,66).Manycontaminatedsubsurfaceenvironmentsare,however,anoxic(29,37,38,50,54).The ability of microbial consortia to anaerobically degrade ben-zenehasbeendemonstratedwithadiversityofelectronacceptors,and insights into potential metabolic pathways have been ob-tained (1, 2, 5, 8, 16, 17, 34, 45, 65). However, pure cultures arerequired for definitive genetic and biochemical analyses.Strains of