title: In situ protein-SIP highlights Burkholderiaceae as key players degrading toluene by para ring hydroxylation in a constructed wetland model.
abstract: In constructed wetlands, organic pollutants are mainly degraded via microbial processes. Helophytes, plants that are commonly used in these systems, provide oxygen and root exudates to the rhizosphere, stimulating microbial degradation. While the treatment performance of constructed wetlands can be remarkable, a mechanistic understanding of microbial degradation processes in the rhizosphere is still limited. We investigated microbial toluene removal in a constructed wetland model system combining 16S rRNA gene sequencing, metaproteomics and (13) C-toluene in situ protein-based stable isotope probing (protein-SIP). The rhizospheric bacterial community was dominated by Burkholderiales and Rhizobiales, each contributing about 20% to total taxon abundance. Protein-SIP data revealed that the members of Burkholderiaceae, the proteins of which showed about 73% of (13) C-incorporation, were the main degraders of toluene in the planted system, while the members of Comamonadaceae were involved to a lesser extent in degradation (about 64% (13) C-incorporation). Among the Burkholderiaceae, one of the key players of toluene degradation could be assigned to Ralstonia pickettii. We observed that the main pathway of toluene degradation occurred via two subsequent monooxygenations of the aromatic ring. Our study provides a suitable approach to assess the key processes and microbes that are involved in the degradation of organic pollutants in complex rhizospheric ecosystems.
authors.affiliation: Department of Proteomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.|Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Lünsmann
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Kappelmeyer
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Benndorf
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Martinez-Lavanchy
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Taubert
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Adrian
authors.affiliation: Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research - HZI, Braunschweig, Germany.
authors.forename: Marcia
authors.initials: M
authors.lastname: Duarte
authors.affiliation: Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research - HZI, Braunschweig, Germany.
authors.forename: Dietmar H
authors.initials: DH
authors.lastname: Pieper
authors.affiliation: Department of Proteomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.|Department of Metabolomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.|Department of Biotechnology, Chemistry and Environmental Engineering, University of Aalborg, Aalborg, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: von Bergen
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Jochen A
authors.initials: JA
authors.lastname: Müller
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Heipieper
authors.affiliation: Department of Proteomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Jehmlich
mesh_terms: D001673:Biodegradation, Environmental; D042521:Burkholderiaceae / Q000235:genetics / Q000378:metabolism*; D042621:Comamonadaceae / Q000235:genetics / Q000378:metabolism*; D006900:Hydroxylation; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D012988:Soil Microbiology; D014050:Toluene / Q000378:metabolism*; D053833:Wetlands
chemical_list: D012336:RNA, Ribosomal, 16S; D014050:Toluene