|| 要旨トップ | 目次 |||日本生態学会第63回全国大会 (2016年3月、仙台) 講演要旨
一般講演（ポスター発表） P1-406 (Poster presentation)
About 6-16% of atmospheric CH4 emitted from natural sources is derived from lake ecosystems. It is believed that CH4 is produced in anoxic sediments via methanogenesis. However, recent studies revealed that aerobic planktonic microbes can produce methane through the use of methylphosphonic acid (MPn) by C-P lyase enzyme. But, there is no study examining the effects of cell nutritional conditions (N starved or P starved) on aerobic methane production.
We performed the batch-culture experiments of planktonic microbes to identify the effects of cell starvation on aerobic methane production rates under N and P limited conditions. First, we confirmed aerobic CH4 production by MPn addition treatment. Moreover, we found that MPn + Ni addition accelerated the aerobic CH4 production. However, MPn + Pi addition did not increase the CH4 production, indicating the opportunistic utilization of MPn alternative to Pi under phosphorus limited conditions. The present results suggest that the input of excess N into lake ecosystems promotes the metabolism of MPn by planktonic microorganisms, which leads to increase of aerobic methane production in phosphorus-limited oligotrophic lakes.