Publication Details
Category Text Publication
Reference Category Journals
DOI 10.1016/j.jes.2018.09.008
Title (Primary) Individual stages of bacterial dichloromethane degradation mapped by stable carbon and chlorine isotope analysis
Author Torgonskaya, M.L.; Zyakun, A.M.; Trotsenko, Y.A.; Laurinavichius, K.S.; Kümmel, S.; Vuilleumier, S.; Richnow, H.H.
Journal Journal of Environmental Sciences
Year 2019
Department ISOBIO
Volume 78
Page From 147
Page To 160
Language englisch
Keywords Dichloromethane (DCM); Microbial degradation; Aerobic methylotrophic bacteria; Dichloromethane dehalogenase; Fractionation of stable carbon and chlorine isotopes
UFZ wide themes ProVIS;
Abstract The fractionation of stable carbon and chlorine isotopes of dichloromethane (CH2Cl2, DCM) upon dechlorination by cells of the aerobic methylotroph Methylobacterium extorquens DM4 and by purified DCM dehalogenases of the glutathione S-transferase family was analyzed. Isotope effects for individual steps of the multi-stage DCM degradation process, including transfer across the cell wall from the aqueous medium to the cell cytoplasm, dehalogenase binding, and catalytic reaction, were considered. The observed carbon and chlorine isotope fractionation accompanying DCM consumption by cell supensions and enzymes was mainly determined by the breaking of CCl bonds, and not by inflow of DCM into cells. Chlorine isotope effects of DCM dehalogenation were initially masked in high density cultures, presumably due to inverse isotope effects of non-specific DCM oxidation under conditions of oxygen excess. Glutathione cofactor supply remarkably affected the DCM δ13C/δ37Cl ratio, which increased from 7.2–8.6 to 9.6–10.5 under conditions of glutathione deficiency. This suggests that enzymatic reaction of DCM with glutathione thiolate may involve stepwise breaking and making of bonds with the carbon atom of DCM, unlike uncatalyzed reaction, which is a one-stage process, as shown by quantum-chemical modeling.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=21026
Torgonskaya, M.L., Zyakun, A.M., Trotsenko, Y.A., Laurinavichius, K.S., Kümmel, S., Vuilleumier, S., Richnow, H.H. (2019):
Individual stages of bacterial dichloromethane degradation mapped by stable carbon and chlorine isotope analysis
J. Environ. Sci. 78 , 147 - 160