REDUCTIVE DECHLORINATION OF HALOGENATED PHENOLS BY A SULFATE-REDUCINGCONSORTIUM

A sulfidogenic consortium enriched from an estuarine sediment utilized 4-chlorophenol as a sole source of carbon and energy. Reductive dechl orination as the initial step in chlorophenol degradation by the sulfa te-reducing consortium was confirmed with the use of chloro-fluorophen ols. Both 4-chloro-2-fluorophenol and 4-chloro-3-fluorophenol were dec hlorinated, resulting in stoichiometric accumulation of 2-fluorophenol and 3-fluorophenol, respectively. The fluorophenols were not degraded further. Furthermore, phenol was detected as a transient intermediate during degradation of 4-chlorophenol in the presence of 3-fluoropheno l. Reductive dechlorination was inhibited by molybdate and did not occ ur in the absence of sulfate. These results indicate that 4-chlorophen ol is reductively dechlorinated to phenol under sulfate-reducing condi tions and mineralization of the phenol ring to CO2 is coupled to sulfa te reduction. (C) 1998 Federation of European Microbiological Societie s. Published by Elsevier Science B.V.