title: Syntrophic acetate oxidation under thermophilic methanogenic condition in Chinese paddy field soil.
abstract: The aim of the present work was to determine and compare the degradation of acetate in a Chinese rice field soil at 25°C and 50°C, respectively, and to identify specifically the active organisms involved in syntrophic acetate oxidation. Soil was preincubated anaerobically for 30 days to reduce alternative electron acceptors other than CO(2). The [2-(13)C] acetate (99% (13)C) was added twice: 0 day and 19 days after preincubation. Addition of [2-(13)C] acetate resulted in an immediate increase of (13)C labeled CH(4) but non-labeling of CO(2) at 25°C. The methanogen community was dominated by Methanosarcinaceae and Methanocellales at 25°C. In contrast, the addition of [2-(13)C] acetate at 50°C resulted in a rapid increase of (13)CO(2). The (13)C labeling of CH(4) gradually increased and reached a similar value to CO(2) (13% (13)C) at the end of incubation (40 days). Nearly all archaeal 16S rRNA genes detected at 50°C belonged to hydrogenotrophic Methanocellales. DNA-based stable isotope probing analysis revealed that the organisms related to Thermacetogenium lineage and the unclassified Thermoanaerobacteraceae group were intensively labeled with (13)C in the incubations at 50°C. Thus, acetate was converted to CH(4) and CO(2) through aceticlastic methanogenesis at 25°C, while syntrophic acetate oxidation occurred at 50°C.
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Rui
authors.forename: Qiongfen
authors.initials: Q
authors.lastname: Qiu
authors.forename: Yahai
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000085:Acetates / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D002247:Carbon Isotopes / Q000032:analysis; D016172:DNA Fingerprinting; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D019605:Euryarchaeota / Q000235:genetics / Q000378:metabolism*; D008697:Methane / Q000378:metabolism; D012275:Oryza / Q000382:microbiology; D010084:Oxidation-Reduction; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D000085:Acetates; D002247:Carbon Isotopes; D019641:DNA, Archaeal; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012987:Soil; D008697:Methane