Elucidating MTBE degradation in a mixed consortium using a multidisciplinary approach

• Published in: FEMS microbiology ecology Vol. 73; no. 2; pp. 370 - 384
• Main Authors: Bastida, Felipe, Rosell, Mònica, Franchini, Alessandro G, Seifert, Jana, Finsterbusch, Stefanie, Jehmlich, Nico, Jechalke, Sven, von Bergen, Martin, Richnow, Hans H
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.08.2010; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Acidovorax; Animal, plant and microbial ecology; Bacteria - genetics; Bacteria - metabolism; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; Carbon; Carbon - metabolism; Carbon 13; Carbon Isotopes - metabolism; Carbon sources; Comamonadaceae; Comamonas; Consortia; Culture; Culture Media; Degradation; Delftia acidovorans; DNA, Bacterial - genetics; Ecology; Enrichment; Fundamental and applied biological sciences. Psychology; Gasoline; Gene libraries; Gene Library; Gene sequencing; Hydrogenophaga; isotope fractionation; Isotopes; Isotopic enrichment; Methyl Ethers - metabolism; Microbial ecology; Microbiology; Microorganisms; Mixed culture; Molecular biology; MTBE; MTBE degradation; Phylogeny; protein-stable isotope probing; Proteins; Reaction mechanisms; Rhodobacter; RNA, Ribosomal, 16S - genetics; rRNA 16S; Sequence Analysis, DNA; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Stable isotopes; Structure-function relationships; Thiothrix unzii; Water Pollutants, Chemical - metabolism; USA; protein-stable isotope probing; MTBE degradation; isotope fractionation; Degradation; Additive; Fractionation; Isotopes; Protein
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.2010.00889.x

The structure and function of a microbial community capable of biodegrading methyl-tert-butyl ether (MTBE) was characterized using compound-specific stable isotope analysis (CSIA), clone libraries and stable isotope probing of proteins (Protein-SIP). The enrichment culture (US3-M), which originated from a gasoline-impacted site in the United States, has been enriched on MTBE as the sole carbon source. The slope of isotopic enrichment factors (εC of -2.29±0.03[per thousand]; εH of -58±6[per thousand]) for carbon and hydrogen discrimination (Δδ²H/Δδ¹³C) was on average equal to Λ=24±2, a value closely related to the reaction mechanism of MTBE degradation in Methylibium petroleiphilum PM1. 16S rRNA gene libraries revealed sequences belonging to M. petroleiphilum PM1, Hydrogenophaga sp., Thiothrix unzii, Rhodobacter sp., Nocardiodes sp. and different Sphingomonadaceae bacteria. Protein-SIP analysis of the culture grown on ¹³C-MTBE as the only carbon source revealed that proteins related to members of the Comamonadaceae family, such as Delftia acidovorans, Acidovorax sp. or Comamonas sp., were not ¹³C-enriched, whereas proteins related to M. petroleiphilum PM1 showed an average incorporation of 94.5 atom%¹³C. These results indicate a key role for this species in the degradation of MTBE within the US3-M consortia. The combination of CSIA, molecular biology and Protein-SIP facilitated the analysis of an MTBE-degrading mixed culture from a functional and phylogenetic point of view.