Complete chloroform dechlorination by organochlorine respiration and fermentation

Lee, M; Low, A; Zemb, O; Koenig, J; Michaelsen, A; Manefield, M

HERO ID

1940375

Reference Type

Journal Article

Year

2012

Language

English

PMID

22118646

HERO ID 1940375
In Press No
Year 2012
Title Complete chloroform dechlorination by organochlorine respiration and fermentation
Authors Lee, M; Low, A; Zemb, O; Koenig, J; Michaelsen, A; Manefield, M
Journal Environmental Microbiology
Volume 14
Issue 4
Page Numbers 883-894
Abstract Chloroform (CF, CHCl(3)) is a recalcitrant and toxic environmental pollutant. In this communication we report for the first time a microbial community capable of complete CF dechlorination by metabolic processes. Cultures derived from subsurface soil (3.5 m) could sustain complete dechlorination of CF at levels of least 360 µM at a rate of 40 µM per day. Scrutiny of CF dechlorination revealed two metabolic processes at work. First, CF was respired to dichloromethane (DCM, CH(2) Cl(2)), which was then fermented to acetate, hydrogen and carbon dioxide. Elevated hydrogen partial pressures were found to inhibit the fermentation process. Interspecies hydrogen transfer was observed in the form of methanogenesis and acetogenesis. This suggests that the dechlorination process required syntrophic partners to maintain low hydrogen partial pressures. (13)C-labelled DCM was employed to help elucidate the chemistry of the process and identify bacterial community members involved. CF respiring cultures, where emulsified vegetable oil was supplied as the electron donor and DCM fermenting cultures, where DCM was supplied as the sole organic carbon source were studied separately. Pyrosequencing of these cultures revealed Dehalobacter lineages as a predominant community member in both. Subsequent growth experiments confirmed that the proliferation of Dehalobacter was linked directly to both the dehalorespiration and dehalofermentation processes.
Doi 10.1111/j.1462-2920.2011.02656.x
Pmid 22118646
Wosid WOS:000302540200005
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English