铅-苄嘧磺隆对土壤微生物活性与群落结构的影响

The influence of lead-bensulfuron-methyl complex pollution on soil microbial activities and community structure.

选用苄嘧磺隆除草剂和重金属铅组成复合污染体系,以土壤微生物生物量、微生物代谢熵和磷脂脂肪酸为测试指标,在25℃暗培养条件下研究其对土壤微生物活性和微生物群落结构的影响.结果表明,苄嘧磺隆-铅对土壤微生物活性均有抑制作用,交互作用达显著水平.在低浓度时表现为简单加和作用,高浓度时表现为拮抗作用,浓度是影响交互作用类型的重要因子之一.磷脂脂肪酸图谱分析表明,丛枝菌根真菌的特征磷脂脂肪酸16:1ω5c的相对含量随污染物浓度升高而减少,而真菌特征磷脂脂肪酸18:2ω6,9c和放线菌类特征磷脂脂肪酸10Me17:0和10Me18:0的相对含量均随着污染物浓度升高而增加,2种污染物对微生物群落结构的影响存在较大的差异.

Selecting bensulfuron-methyl （BSM） herbicide and lead （Pb） heavy metal composed the complex pollution system. Using soil microbial biomass, microbial entropy and phospholipid fatty acids （PLFAs） as test indexes, its influence on soil microbial activity and community structure was investigated under the condition of 25℃ dark incubation. BSM and Pb all had inhibition action on soil microbial activity, the interactions reached marked levels, showed simple addition effects at low concentrations and antagonism at high concentrations. The concentration was one of the important factors affecting the types of interactions. Analysis of PLFAs composition demonstrated that the relative content of 16：1ω05c with arbuscular mycorrhizal fungal character decreased with increase of pollutant concentration, whereas the relative content of 18：2 ω06,9c with fungal character and 10Me 17：0 and 10Me 18：0 with actinomyces character all increased with increase of pollutant concentration. The change of these soil PLFAs reflected the change of soil microbial community structure. The influence of two kind of pollutants on microbial community structure existed relatively great variation.