title: Time-resolved DNA stable isotope probing links Desulfobacterales- and Coriobacteriaceae-related bacteria to anaerobic degradation of benzene under methanogenic conditions.
abstract: To identify the microorganisms involved in benzene degradation, DNA-stable isotope probing (SIP) with 13C-benzene was applied to a methanogenic benzene-degrading enrichment culture. Pyrosequencing of ribosomal RNA (rRNA) gene sequences revealed that the community structure was highly complex in spite of a 3-year incubation only with benzene. The culture degraded 98% of approximately 1 mM 13C-benzene and mineralized 72% of that within 63 d. The terminal restriction fragment length polymorphism (T-RFLP) profiles of the buoyant density fractions revealed the incorporation of 13C into two phylotypes after 64 d. These two phylotypes were determined to be Desulfobacterales- and Coriobacteriaceae-related bacteria by cloning and sequencing of the 16S rRNA gene in the 13C-labeled DNA abundant fraction. Comparative pyrosequencing analysis of the buoyant density fractions of 12C- and 13C-labeled samples indicated the incorporation of 13C into three bacterial and one archaeal OTUs related to Desulfobacterales, Coriobacteriales, Rhodocyclaceae, and Methanosarcinales. The first two OTUs included the bacteria detected by T-RFLP-cloning-sequencing analysis. Furthermore, time-resolved SIP analysis confirmed that the activity of all these microbes appeared at the earliest stage of degradation. In this methanogenic culture, Desulfobacterales- and Coriobacteriaceae-related bacteria were most likely to be the major benzene degraders.
authors.affiliation: Research Center for Water Environment Technology, The University of Tokyo.
authors.forename: Mana
authors.initials: M
authors.lastname: Noguchi
authors.forename: Futoshi
authors.initials: F
authors.lastname: Kurisu
authors.forename: Ikuro
authors.initials: I
authors.lastname: Kasuga
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Furumai
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D000693:Anaerobiosis; D001483:Base Sequence; D001554:Benzene / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020564:Deltaproteobacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D019015:Geologic Sediments / Q000382:microbiology; D007564:Japan; D008697:Methane / Q000378:metabolism; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D002247:Carbon Isotopes; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide; D001554:Benzene; D008697:Methane