Reductive Dechlorination of 1, 2, 4-Trichlorobenzene by Staphylococcus epidermidis Isolated from Intestinal Contents of Rats

Abstract

Twelve bacterial strains which were concerned with dechlorination of 1, 2, 4-trichlorobenzene (TCB) were isolated from the intestinal contents of rats and it was found that they belonged to Staphylococcus epidermidis (strain A-F), Staphylococcus saprophyticus (strain G), Streptococcus sp. (strains H and I), Bacillus sp. (strain J), Gram negative rod (strain K) and Lactobacillus sp. (strain L).
In Staphylococcus epidermidis (Strain A), TCB was mainly converted to o-dichlorobenzene
and the latter was preferentially converted to monochlorobenzene (MCB) among dichlorobenzenes (DCBs). These conversions proceeded only under a gas phase of hydrogen. Furthermore, dry and broken cells of intact bacteria also maintained the dechlorinating activities, which were stimulated by the addition of NADPH.
Therefore, it was supposed that the conversion of TCB to MCB via DCBs was reductively carried out by enzymes originating from the isolated bacteria.