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Sci Total Environ

Title:		Vitamin B(12) effects on chlorinated methanes-degrading microcosms: Dual isotope and metabolically active microbial populations assessment
Author(s):		Rodriguez-Fernandez D; Torrento C; Guivernau M; Vinas M; Hunkeler D; Soler A; Domenech C; Rosell M;
Address:		"Grup de Mineralogia Aplicada i Geoquimica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciencies de la Terra, Universitat de Barcelona (UB), c/Marti Franques s/n, 08028 Barcelona, Spain. Electronic address: diana.rodriguez@ub.edu. Centre d'hydrogeologie et de geothermie, Universite de Neuchatel, Rue Emile-Argand 11, Neuchatel 2000, Switzerland. GIRO Joint Research Unit IRTA-UPC, IRTA, Torre Marimon, Caldes de Montbui E-08140, Spain. Grup de Mineralogia Aplicada i Geoquimica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciencies de la Terra, Universitat de Barcelona (UB), c/Marti Franques s/n, 08028 Barcelona, Spain"
Journal Title:		Sci Total Environ
Year:		2018
Volume:		20171018
Issue:
Page Number:		1615 - 1625
DOI:		10.1016/j.scitotenv.2017.10.067
ISSN/ISBN:		1879-1026 (Electronic) 0048-9697 (Linking)
Abstract:		"Field-derived anoxic microcosms were used to characterize chloroform (CF) and carbon tetrachloride (CT) natural attenuation to compare it with biostimulation scenarios in which vitamin B(12) was added (B(12)/pollutant ratio of 0.01 and 0.1) by means of by-products, carbon and chlorine compound-specific stable-isotope analysis, and the active microbial community through 16S rRNA MiSeq high-throughput sequencing. Autoclaved slurry controls discarded abiotic degradation processes. B(12) catalyzed CF and CT biodegradation without the accumulation of dichloromethane, carbon disulphide, or CF. The carbon isotopic fractionation value of CF (EC(CF)) with B(12) was -14+/-4 per thousand, and the value for chlorine (ECl(CF)) was -2.4+/-0.4 per thousand. The carbon isotopic fractionation values of CT (EC(CT)) were -16+/-6 with B(12), and -13+/-2 per thousand without B(12); and the chlorine isotopic fractionation values of CT (ECl(CT)) were -6+/-3 and -4+/-2 per thousand, respectively. Acidovorax, Ancylobacter, and Pseudomonas were the most metabolically active genera, whereas Dehalobacter and Desulfitobacterium were below 0.1% of relative abundance. The dual C-Cl element isotope slope (Lambda=Deltadelta(13)C/Deltadelta(37)Cl) for CF biodegradation (only detected with B(12), 7+/-1) was similar to that reported for CF reduction by Fe(0) (8+/-2). Several reductive pathways might be competing in the tested CT scenarios, as evidenced by the lack of CF accumulation when B(12) was added, which might be linked to a major activity of Pseudomonas stutzeri; by different chlorine apparent kinetic isotope effect values and Lambda which was statistically different with and without B(12) (5+/-1 vs 6.1+/-0.5), respectively. Thus, positive B(12) effects such as CT and CF degradation catalyst were quantified for the first time in isotopic terms, and confirmed with the major activity of species potentially capable of their degradation. Moreover, the indirect benefits of B(12) on the degradation of chlorinated ethenes were proved, creating a basis for remediation strategies in multi-contaminant polluted sites"
Keywords:		"Bacteria/*metabolism *Biodegradation, Environmental Carbon Isotopes Halogenation Methane/*metabolism RNA, Ribosomal, 16S Spain Vitamin B 12/*metabolism Volatile Organic Compounds/metabolism Water Pollutants, Chemical/metabolism Csia Carbon tetrachloride C;"
Notes:		"MedlineRodriguez-Fernandez, Diana Torrento, Clara Guivernau, Miriam Vinas, Marc Hunkeler, Daniel Soler, Albert Domenech, Cristina Rosell, Monica eng Netherlands 2017/10/22 Sci Total Environ. 2018 Apr 15; 621:1615-1625. doi: 10.1016/j.scitotenv.2017.10.067. Epub 2017 Oct 18"