Author:
Holland Sophie I,Ertan Haluk,Manefield Michael J,Lee Matthew
Abstract
AbstractDichloromethane (DCM; CH2Cl2) is a toxic groundwater pollutant that also has a detrimental effect on atmospheric ozone levels. As a dense non-aqueous phase liquid, DCM migrates vertically through groundwater to low redox zones, yet information on anaerobic microbial DCM transformation remains scarce due to a lack of cultured organisms. We report here the characterisation of strain DCMF, the dominant organism in an anaerobic enrichment culture (DFE) that is capable of fermenting DCM to the environmentally benign product acetate. Stable carbon isotope experiments demonstrated that the organism assimilated carbon from DCM and bicarbonate via the Wood-Ljungdahl pathway. Strain DCMF is the first anaerobic DCM-degrading bacterium also shown to metabolise non-chlorinated substrates. It appears to be a methylotroph utilising the Wood-Ljungdahl pathway for metabolism of methyl groups from methanol, choline, and glycine betaine, which has implications for the flux of climate-active compounds from subsurface environments. Community profiling and enrichment of the cohabiting taxa in culture DFE to the exclusion of strain DCMF suggest that it is the sole organism in this culture responsible for substrate metabolism, while the cohabitants persist via necromass recycling. Genomic and physiological evidence support placement of strain DCMF in a novel genus, ‘Candidatus Formamonas warabiya’.
Publisher
Cold Spring Harbor Laboratory
Reference59 articles.
1. Removal of dichloromethane from ground and wastewater: A review
2. Naturally Occurring Organohalogen Compounds: A Comprehensive Update. In: Progress in the Chemistry of Organic Natural Products;Springer Science & Business Media,2010
3. Carpenter LJ , Reimann S. Scientific assessment of ozone depletion: 2014. In: Engel A , Montzka SA , editors. Global Ozone Research and Monitoring Project - Report No 55. World Meteotological Organization; 2014.
4. Efficiency of short-lived halogens at influencing climate through depletion of stratospheric ozone;Nat Geosci,2015
5. Growth in stratospheric chlorine from short-lived chemicals not controlled by the Montreal Protocol;Geophys Res Lett,2015