title: Genomic features of uncultured methylotrophs in activated-sludge microbiomes grown under different enrichment procedures.
abstract: Methylotrophs are organisms that are able to grow on C1 compounds as carbon and energy sources. They play important roles in the global carbon cycle and contribute largely to industrial wastewater treatment. To identify and characterize methylotrophs that are involved in methanol degradation in wastewater-treatment plants, methanol-fed activated-sludge (MAS) microbiomes were subjected to phylogenetic and metagenomic analyses, and genomic features of dominant methylotrophs in MAS were compared with those preferentially grown in laboratory enrichment cultures (LECs). These analyses consistently indicate that Hyphomicrobium plays important roles in MAS, while Methylophilus occurred predominantly in LECs. Comparative analyses of bin genomes reconstructed for the Hyphomicrobium and Methylophilus methylotrophs suggest that they have different C1-assimilation pathways. In addition, function-module analyses suggest that their cell-surface structures are different. Comparison of the MAS bin genome with genomes of closely related Hyphomicrobium isolates suggests that genes unnecessary in MAS (for instance, genes for anaerobic respiration) have been lost from the genome of the dominant methylotroph. We suggest that genomic features and coded functions in the MAS bin genome provide us with insights into how this methylotroph adapts to activated-sludge ecosystems.
authors.affiliation: School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Fujinawa
authors.affiliation: School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Asai
authors.affiliation: School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Miyahara
authors.affiliation: School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kouzuma
authors.affiliation: Graduate School of Science and Technology, Niigata University, Niigata, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.affiliation: School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D020582:Hyphomicrobium / Q000254:growth & development*; D020629:Methylophilus / Q000254:growth & development*; D064307:Microbiota / Q000502:physiology*; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage