Dehalogenation of lindane (gamma-hexachlorocyclohexane) by anaerobic bacteria from marine sediments and by sulfate-reducing bacteria

Marine sediments from around burrows of Saccoglossus kowalevskii, a tribrom opyrrole-producing marine hemichordate, were used to develop anaerobic enri chment cultures supplemented with lindane and a mixture of short chain fatt y acids. These enrichments consumed lindane and both monochlorobenzene and benzene were detected as transformation products. Cultures transferred to s ediment-free media containing citrate, lactate, yeast extract and sulfate a lso dehalogenated lindane. Lindane transformation was inhibited by the addi tion of molybdate. Lindane loss was not observed when the enrichment was cu ltured on lactate and citrate in the absence of sulfate, suggesting that su lfate-reducing bacteria transform lindane. . Monoclorobenzene and benzene w ere identified as two transformation products in the lactate, citrate and s ulfate enrichment culture. Pure cultures were used in order to confirm the ability of sulfate-reducing bacteria to dehalogenate lindane. Cell suspensi ons of Desulfovibrio gigas ATCC 19364, Desulfovibrio africunus ATCC 19997 a nd Desulfococcus multivorans ATCC 33890 were also able to dehalogenate lind ane to benzene and monochlorobenzene. Actively growing and autoclaved cell suspensions of Desulfovibrio gigas were capable of lindane transformation w hile filler-sterilized cultures were not. (C) 1999 Federation of European M icrobiological Societies. Published by Elsevier Science B.V. All rights res erved.