洛克沙胂暴露胁迫对土壤微生物群落结构特征的影响

采用磷脂脂肪酸(phospholipid fatty acid,PLFA)方法,分析了洛克沙胂残留对土壤微生物群落结构的影响特征。结果表明,在整个采样周期中,每克土壤总PLFA含量在洛克沙胂胁迫影响下出现明显降低,且存在一定的剂量依赖效应。经主成分分析,第1周,洛克沙胂低浓度组(w=15 mg·kg-1)土壤微生物群落结构和对照组差异不明显,第2、3、5、8周,各组土壤微生物群落结构多样性的类型差异显著,其中高浓度组(w=150 mg·kg-1)与对照组差异最大。结果表明,洛克沙胂可致土壤微生物群落结构多样性改变,暴露浓度越高其作用越强。同时,洛克沙胂对土壤微生物群落结构多样性的影响还表现出时间差异,在暴露胁迫的后期(第5、8周),洛克沙胂的影响逐步减弱,可能与洛克沙胂在土壤中发生化学结构改变和降解有关。

Roxarsone Residue affects the Microbial Community Structure in Soil

By using phospholipid fatty acid ( PLFA) approach, the structural characteristics of soil microbial community caused by residue of roxarsone was studied. The results showed that the total PLFA in soil in treatment was significantly decreased after 1week exposure in a dose-dependent manner, except in the lower roxarsone treatment (i.e., w=15mg·kg^-1). The difference between control and treatments appeared to be larger with increase of the roxarsone concentration. It was concluded that the structure of soil microorganisms have been affected by the residue of roxarsone in soil and the effectiveness could be enhanced with exposure time and concentrations. It was propoed that the time dependent variation? in structure of soil microorganisms could be caused by by the chemical conversion and degradation of? Roxarsone in soil.