Journal of Environmental Biology

Long-term survival of methanogens of an anaerobic digestion sludge under starvation and temperature variation

Tae Gwan Kim, Taewoo Yi, Jung-Hee Lee and Kyung-Suk Cho*

Global Top 5 Research Programme, Department of Environmental Science and Engineering, Ewha Womans University,

11-1 Daehyun-dong, Seodaemun-gu, Seoul 120-750, Korea

*Corresponding Authors Email : kscho@ewha.ac.kr

Publication Data

Paper received:

13 September 2013

Revised received:

02 May 2014

Accepted:

20 June 2014

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^?C to 20^?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?10⁷ to 1.2?10⁷ mcrA copies?ml^-1 (volume basis) at 50 ?C, and then increased to 4.4 ?10⁷ mcrA copies?ml^-1 at 20 ?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. ?? 

 Key words

Methanogens, Population dynamics, Starvation, Temperature 

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