水稻田中产甲烷菌数量和优势种

AMOUNT AND DOMINANT SPECIES OF MPB IN SUBMERGED PADDY SOIL

采用改良的亨格特(Hungate)厌氧技术,用MPN法和滚管法同时测定水稻不同生育期土壤中的产甲烷菌数量有明显差异,在混合基质中生长的产甲烷菌数量,早稻在分蘖末期数量最高,可达3.6×10^(10)个/克干土;在H_2和CO_2生长的产甲烷菌数量,晚稻在分蘖盛期明显增高,到乳熟期可高达3.1×10^(11)个/克干土;在甲酸钠和乙酸钠基质中生长的产甲烷菌数量,晚稻在分蘖盛期较高,分别达3.7×10~8个/克千土和1.2×10~8个/克干土;在甲醇基质中生长的产甲烷菌数量,晚稻在各生育期差异不显著。不同深度土壤中产甲烷菌数量无显著差异。施用有机肥料在一定程度上可促进产甲烷菌数量的递增。水稻土中占优势的产甲烷菌种群为甲酸甲烷杆菌(Methanobacterium formicicum)、马氏甲烷八叠球菌(Methanosarcina mazei)和巴氏甲烷八叠球菌(Methanosarcina barkeri)。

With improved Hungate anaerobic technique, the amounts of methane——producing bacreria (MPB) in the submerged paddy soil planting rice crop were determined by the MPN (The Most Probable Number) method and the roll tube method at the same time. The esults obtained showed that the amounts of MPB during different growing periods of rice were significantly different, the amount of MPB grown on mixed substrate was the highest at the late tillering stage of early rice, up to 3.6×10^(10)/g dry soil; that on H_2/CO_2 increased significantly at the vigorously tillering stage of late rice, reaching 3.1×10^(11)/g dry soil at milk ripening stage; the amounts of MPB grown on formate and acetate were higher, about 3.7×10~8/g dry soil and 1.2×10~8/g dry soil respectively at the vigorously tillering stage of late rice; and that of MPB grown on methanol had no significant difference during the different growing periods being, about 3.5×10~5/g dry soil.The amounts of MPB had no marked difference in soil at different depths.A certain difference was found in the number of MPB under conditions of different kinds of fertilizers applied, and addtion of organic manure stimulated methane prodection.The dominant species of methanogenic bacteria in the paddy soil were Methanobacterium formicicum, Methanosarcina barkeri and Methanosarcina mazei.