Evaluating microbial robustness in continuous vs. feast-famine bioreactors via methane-oxidizing activity by q-PCR.

Abstract

The microbial robustness of three stirred tank reactors (STRs) treating CH4 at low concentrations (4-5 % v/v) operated under feast-famine and continuous feeding mode was systematically evaluated through the analysis of the pmoA gene encoding the enzyme methane monooxygenase. In addition, the elimination capacities (EC) and CO2 production rates of the microbial communities in the STRs were also assessed. This work revealed the extremely fast recovery of CH4 biodegradation activity of methanotrophs after a 5-days starvation period regardless of the previous history of the microbial community. The fact that methane-oxidizing activity was not damaged under long starvation periods suggested the high robustness of biofiltration for the treatment of diluted CH4 emissions.