Open AccessReductive dechlorination of perchloroethylene and the role of methanogens
Author(s) -
Fathepure Babu Z.,
Boyd Stephen A.
Publication year - 1988
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1988.tb02706.x
Subject(s) - reductive dechlorination , tetrachloroethylene , environmental chemistry , chemistry , environmental science , trichloroethylene , biodegradation , organic chemistry
Perchloroethylene (PCE) was reductively dechlorinated to trichloroethylene in a 10% anaerobic sewage sludge. About 80% of the initially added PCE (300 nmol) was dechlorinated within three weeks. The calculated rates were 250 nM and 445 nM · day −1 during the first and second weeks of incubation, respectively. The depletion of PCE varied in sludges obtained from different sources. The role of methanogenesis in the dechlorination of PCE was evaluated by inhibiting the methanogens by addition of bromoethane sulfonic acid, a potent methanogenic inhibitor. Dechlorination of PCE was significantly inhibited in sludges amended with the inhibitor. Almost 41–48% less PCE was dechlorinated in sludges containing 5 mM BESA, indicating a relation between the two processes (methanogenesis and dechlorination). Direct proof that methanogens can transform chlorinated aliphatic compounds was obtained using axenic cultures of acetate‐cleaving methanogens. Methanosarcina sp , originally isolated from a chlorophenol degrading consortium, showed significantly higher dechlorinating activity as compared to Ms. mazei . Based on these studies and other recently reported observations, it appears that methanogens/methanogenesis play an important role in the anaerobic dechlorination of chlorinated aliphatics such as PCE.