温度对甲烷产生和氧化的影响

综述了温度对土壤产甲烷和氧化甲烷的影响及其机制．温度主要通过土壤中产甲烷菌的优势菌发生更替来改变土壤的产甲烷能力．较高温条件下产甲烷菌以乙酸和H2／CO2都能利用的甲烷八叠球菌(Methanosarcinaceae)为主，使得土壤处于较高的产甲烷状态．较低温条件下产甲烷菌以只能利用乙酸的甲烷毛菌(Methanosaetaceae)为主，土壤形成甲烷的能力相对较弱．温度提高可以显著地增加甲烷的产生，Q10为1．5-28，平均4．1，但是温度效应明显受控于底物浓度，提高底物浓度降低了产甲烷菌对底物的亲和力，相应地增加了度效应，因此在较低温条件下提高底物浓度可以促进甲烷的产生．温度对大气甲烷氧化的影响弱于产甲烷，甲烷氧化菌较少受温度变化的影响，即便在较低温条件下，土壤也具有一定的氧化大气甲烷能力，原因尚不清楚，可能与甲烷氧化菌对大气甲烷具有较高的亲和力有关，有待进一步研究．

Effect of temperature on methane production and oxidation in soils

The influence of temperature and its mechanism on methane production and oxidation in soils were reviewed in this paper. Temperature can alter the soil ability to produce methane through changing types of dominant methanogens in archaeal community. Dominant methanogen is Methanosarcinaceae at higher temperature which can utilize both H 2/CO 2 and acetate as the precursor to produce methane, while Methanosaetaceae at lower temperature which only use acetate as the precursor and produce far less methane than do Methanosarcinaceae. Increasing soil temperature apparently raises soil ability to produce methane, which is called temperature effectiveness and expressed as Q 10 with a range from 1.5 to 28 and an average of 4.1. There is an obviously positive correlation between temperature effectiveness (Q 10) on methane production and substrate content. As compared to methane production, effect of temperature on methane oxidation is lower, which may be related to the strong affinity of methanotrophs for methane.