Heat stress and methane-oxidizing bacteria: Effects on activity and population dynamics

We studied the effects of an acute temperature increase (heat stress) on methane oxidation and methanotroph community structure in a laboratory-scale experiment with paddy soil. Methane oxidation was resilient, recovering already six days after heat stress, and later on even reached higher values than in the control. It was consistently shown by qPCR and by terminal restriction length polymorphism (T-RFLP) that type II methanotrophs increased over time. While this was a general trend, the initial increase of type II was much more pronounced after heat stress at 45 °C. Type I methanotrophs were inversely correlated to type II and temperature. Overall, heat stress is a potential factor shifting the community towards a dominance of type II methanotrophs.