不同浓度铜污染对水稻土甲烷氧化菌群落结构的影响

近年来,随着含铜矿产的开采、冶炼和制造等工业“三废”的排放、含铜农药与杀菌剂的长期大量施用以及城市污泥的堆肥利用,农田土壤铜污染日趋严重。土壤含铜量一旦超出其环境承载力,就会对植物、动物和土壤微生物产生危害,严重威胁到生态系统的稳定和人类的健康1]。我国是水稻生产大国,其种植面积达全国粮食作物栽培面积的1/4,因此,水稻土在我国粮食生产中占有及其重要的地位,是具有重大经济意义的土壤资源2]。研究表明,过量铜会对水稻根系产生毒害,进而推迟抽穗期,降低产量3]。铜污染不仅会危害作物地上部分的生长发育,同时也会导致土壤微生物数量、呼吸强度、微生物商、代谢商等的变化,并对微生物的活性和功能产生影

Effect of different copper concentrations on methanotrophic community structure in paddy soil

Variations of diversity of methanotrophs in paddy soil contaminated by copper were investigated using denaturing gradient gel electrophoresis (DGGE). The results showed that the Shannon index and Richness were 2.956 and 19 respectively from the samples without copper contamination, while the indices, 2.664 and 16, 1.790 and 6, 0.693 and 2 were retrieved from the samples with low, medium and high copper pollution respectively. The dominance of Methylomonas, Methylobacter and Methylococcus were 0.218, 0.223 and 0.559 from the samples without copper application, while the indices, 0.102, 0.249 and 0.649, 0.092, 0.285 and 0.585, 0, 0.509 and 0.491 were retrieved from the samples with low, medium and high copper concentration respectively. The results indicated that the Shannon index and Richness of methanotrophs seemed to response to the copper contamination in a negative manner. Meantime, the variation of the responses of different species to the copper contamination was observed that with the increase of copper concentration, the dominances of Methylomonas and Methylobacter ascended and descended respectively, while the dominance of Methylococcus ascended followed by descended.