Microbial metabolism of haloaromatics: isolation and properties of a chlorobenzene-degrading bacterium.

A chlorobenzene-degrading bacterium was isolated by continuous enrichment from a mixture of soil and sewage samples. This organism, strain WR1306, was grown in a chemostat on a mineral medium with chlorobenzene being supplied through the vapor phase with a critical Dc value at a dilution rate of 0.55 h-1. Maximum growth rates in batch culture were accomplished at substrate concentrations of less than or equal to 0.5 mM in the culture medium. During growth on chlorobenzene, stoichiometric amounts of chloride were released. Respiration data and enzyme activities in cell extracts as well as the isolation of 3-chlorocatechol from the culture fluid are consistent with the degradation of chlorobenzene via 3-chloro-cis-1,2-dihydroxycyclohexa-3,5-diene, 3-chlorocatechol, 2-chloro-cis,cis-muconate, trans-4-carboxymethylenebut-2-en-4-olide, maleylacetate, and 3-oxoadipate.