title: Long-term survival of methanogens of an anaerobic digestion sludge under starvation and temperature variation.
abstract: To investigate starvation effect on methanogen community, two identical membrane reactors were continuously operated for 84 consecutive days, with a temperature change from 50 degrees C to 20 degrees C. Continuous feeding washed out 97% biomass from reactors during the experimental period. Quantitative PCR, using mcrA genes, indicated that the methanogen abundance decreased from 7.0 x 10(7) to 1.2 x 10(7) mcrA copies ml(-1) (volume basis) at 50 degrees C, and then increased to 4.4 x 10(7) mcrA copies ml(7) at 20 degrees C (p<0.05). Correspondence analysis indicated that methanogen communities were distinctly grouped by each temperature. Canonical correspondence analysis indicated that temperature showed a significant correlation with the methanogen community composition. These results suggest that methanogens can survive for a long time (at least more than 84 days) under starvation conditions, and that temperature could be a primary factor determining the density and community of methanogens.
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Kim
authors.forename: Taewoo
authors.initials: T
authors.lastname: Yi
authors.forename: Jung-Hee
authors.initials: JH
authors.lastname: Lee
authors.forename: Kyung-Suk
authors.initials: KS
authors.lastname: Cho
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D019149:Bioreactors; D008567:Membranes, Artificial; D008697:Methane / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid
chemical_list: D008567:Membranes, Artificial; D012722:Sewage; D008697:Methane