重金属镉对水田土壤微生物基因多样性的影响  

Effect of Cadmium on Diversity of Microbial Genes in Paddy Soil

作　　者：段学军[1] 黄春晓[1] 

机构地区：[1]中原工学院能源与环境学院,郑州450007

出　　处：《应用与环境生物学报》2008年第4期510-513,共4页Chinese Journal of Applied and Environmental Biology

基　　金：河南省教育厅自然科学基金项目(No. 200510465005);河南省高等学校青年骨干教师资助计划~~

摘　　要：采用16SrDNADGGE分析技术,探讨了不同处理时间、不同浓度镉胁迫条件下水田土壤微生物种群的基因多样性.研究发现,随着处理时间的不同,各处理间的土壤微生物基因多样性差异存在明显不同,培养初期镉对土壤微生物种群毒害作用非常明显,土壤微生物基因多样性下降,但培养后期不同处理之间DNA基因型差异很小,丰度差异较大.在土壤培养初期、含镉3～10mg/kg的培养基上出现一条新增条带,为对照及低镉浓度土壤所没有,镉形态稳定后会消失,说明土壤中可能存在适宜镉浓度下良好生长的微生物种,经序列测定及与网上比对分析,与一株Uncultured bacteriumsp.具有96%的相似率,初步确定为一不可培养细菌种,以其作为淹水条件下镉污染初期的报告基因有一定的可行性.Diversity variations of microbial genes in submerged paddy soil stressed by heavy metal cadmium were studied by using modern molecular biotechnology, including directly extracting total DNA from paddy soil, amplifying 16S rDNA and their V3 variable region by PCR, and denaturing gradient gel electrophoresis （DGGE）. Bacterial communities were quantified by analyzing the DGGE band patterns. The genetic clusters and correlative comparison of the bacterial communities were also analyzed based on the DGGE finger-print. The result showed that there were some significant differences in bacterial communities in paddy soil treated with different cadmium concentrations. Additionally, the diversity of the bacterial communities was obviously corrupted by cadmium at the early stage of the culture, and it reduced as the concentration of Cd^2＋ increased, but small difference was found at the late stage of the culture for cadmium could only affect the degree of bacterial abundance. The result also showed that there was a new band in the early cultured soil DGGE pattern treated with 3-10 mg/kg cadmium, which was not found in CK and other soils treated with low Cd^2＋concentration. The extracting, sequencing and 16S rRNA gene analysising results showed that there was about 96% of comparability between the sequence coming from the band and a uncultured bacterial gene sequence accessed on the GenBank database, and a microbe could possibly grow in the soil treated with suitable concentration of Cd^2＋. This strain be possibly used to indicate the early contamination degree of paddy soil by Cd^2＋. Fig 6, Ref 18

关 键 词：DGGE 镉 稻田 土壤微生物 基因多样性 

分 类 号：S154.3[农业科学—土壤学] X171[农业科学—农业基础科学]