Pollutant degradation by a Methylocystis strain SB2 grown on ethanol: bioremediation via facultative methanotrophy.

TitlePollutant degradation by a Methylocystis strain SB2 grown on ethanol: bioremediation via facultative methanotrophy.
Publication TypeJournal Article
Year of Publication2011
AuthorsIm J, Semrau JD
JournalFEMS Microbiol Lett
Volume318
Issue2
Pagination137-42
Date Published2011 May
ISSN1574-6968
KeywordsAutotrophic Processes, Biodegradation, Environmental, Environmental Pollutants, Ethanol, Hydrocarbons, Chlorinated, Methane, Methylocystaceae
Abstract

A facultative methanotroph, Methylocystis strain SB2, was examined for its ability to degrade chlorinated hydrocarbons when grown on methane or ethanol. Strain SB2 grown on methane degraded vinyl chloride (VC), trans-dichloroethylene (t-DCE), trichloroethylene (TCE), 1,1,1-trichloroethane (1,1,1-TCA), and chloroform (CF), but not dichloromethane (DCM). Growth on methane was reduced in the presence of any chlorinated hydrocarbon. Strain SB2 grown on ethanol degraded VC, t-DCE, and TCE, and 1,1,1-TCA, but not DCM or CF. With the exception of 1,1,1-TCA, the growth of strain SB2 on ethanol was not affected by any individual chlorinated hydrocarbon. No degradation of any chlorinated hydrocarbon was observed when acetylene was added to ethanol-grown cultures, indicating that this degradation was due to particulate methane monooxygenase (pMMO) activity. When mixtures of chlorinated alkanes or alkenes were added to cultures growing on methane or ethanol, chlorinated alkene degradation occurred, but chlorinated alkanes were not, and growth was reduced on both methane and ethanol. Collectively, these data indicate that competitive inhibition of pMMO activity limits methanotrophic growth and pollutant degradation. Facultative methanotrophy may thus be useful to extend the utility of methanotrophs for bioremediation as the use of alternative growth substrates allows for pMMO activity to be focused on pollutant degradation.

DOI10.1111/j.1574-6968.2011.02249.x
Alternate JournalFEMS Microbiol. Lett.
PubMed ID21362021