Sulfurospirillum multivorans

A comparison had been made of fractionation during the dechlorination of tetrachlo-roethene by Sulfurospirillum multivorans and Desulfitobacterium sp. strain PCE-S in laboratory experiments (Nijenhuis et al. 2005). Isotope fractionation in growing cultures was 1.0052 for Desulfitobacterium sp. and only 1.00042 for Sulfurospirillum multivorans, whereas fractionation was greater in crude cell extracts from both strains. It was concluded that caution should therefore be exercised in applying fractionation factors to the evaluation of in situ bioremediation. 

Reductive Dehalogenases. Anaerobic microorganisms capable of reductive dechlorination of tetrachloroethylene, trichloroethylene, chlorinated phenols, and other chlorinated aromatics have recently been discovered and studied (10,53). The corrinoid reductase of Sulfurospirillum multivorans has been shown. 

Both the active enzyme, the heat-inactivated enzyme from Sulfurospirillum (Dehalos-pirillum) multivorans, and cyanocobalamin are capable of dehalogenating haloacetates (Nenmann et al. 2002), and the rate of abiotic dehalogenation depends on the catalyst that is nsed. 

Toxaphene is a complex mixture of compounds prepared by chlorinating camphene, and contains several hundred polychlorinated bornanes. After incubation with Sulfurospirillum (Dehalospirillum) multivorans only the hexa- (B6-923) and the heptachlorinated (B7-1001) remained. The nonachlorinated congener B9-1679 could be transformed by preferential dechlorination of the em-dichloro groups with formation of the heptachlorinated B7-1001 (Ruppe et al. 2003). Further examination showed that this congener could be dechlorinated to penta- and hexachlorinated bornanes (Ruppe et al. 2004). 

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