title: Temperature impacts differentially on the methanogenic food web of cellulose-supplemented peatland soil.
abstract: The impact of temperature on the largely unresolved intermediary ecosystem metabolism and associated unknown microbiota that link cellulose degradation and methane production in soils of a moderately acidic (pH 4.5) fen was investigated. Supplemental [(13) C]cellulose stimulated the accumulation of propionate, acetate and carbon dioxide as well as initial methane production in anoxic peat soil slurries at 15°C and 5°C. Accumulation of organic acids at 15°C was twice as fast as that at 5°C. 16S rRNA [(13) C]cellulose stable isotope probing identified novel unclassified Bacteria (79% identity to the next cultured relative Fibrobacter succinogenes), unclassified Bacteroidetes (89% identity to Prolixibacter bellariivorans), Porphyromonadaceae, Acidobacteriaceae and Ruminococcaceae as main anaerobic degraders of cellulose-derived carbon at both 15°C and 5°C. Holophagaceae and Spirochaetaceae were more abundant at 15°C. Clostridiaceae dominated the degradation of cellulose-derived carbon only at 5°C. Methanosarcina was the dominant methanogenic taxa at both 15°C and 5°C. Relative abundance of Methanocella increased at 15°C whereas that of Methanoregula and Methanosaeta increased at 5°C. Thaumarchaeota closely related to Nitrosotalea (presently not known to grow anaerobically) were abundant at 5°C but absent at 15°C indicating that Nitrosotalea sp. might be capable of anaerobic growth at low temperatures in peat.
authors.affiliation: Department of Ecological Microbiology, University of Bayreuth, Bayreuth, 95440, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Schmidt
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Horn
authors.forename: Steffen
authors.initials: S
authors.lastname: Kolb
authors.forename: Harold L
authors.initials: HL
authors.lastname: Drake
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000693:Anaerobiosis / Q000502:physiology; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D017753:Ecosystem; D019605:Euryarchaeota / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020387:Food Chain; D008697:Methane / Q000378:metabolism*; D017019:Methanosarcinaceae / Q000145:classification / Q000235:genetics / Q000378:metabolism; D011422:Propionates / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D011422:Propionates; D012336:RNA, Ribosomal, 16S; D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon; D002482:Cellulose; D008697:Methane; D019342:Acetic Acid