应用DGGE技术分析自然免耕土与普通耕作土细菌群落的多样性

Analysis of bacterial communities in no-tillage and tillage soils by denaturing gradient gel electrophoresis

为探明免耕土壤与普通耕作土壤环境中细菌群落的多样性,获取相关优势菌落信息,该研究利用宏基因组学方法获得免耕土和普通耕作土样品总DNA,利用PCR获得16S rDNA V3片段,并进行变性梯度凝胶电泳(Denaturation gradient gel electrophoresis),通过微生物种群丰富度比较两样品中群落的丰富性,同时选取相关DNA条带进行克隆、测序和生物信息学分析。结果显示:免耕土壤中细菌群落多样性更加丰富;两类型土壤样品间细菌群落组成具有显著差异,证明耕作制度影响了土壤细菌群落结构。BLAST分析与系统发生分析结果表明,免耕土壤中特异存在的细菌群落与具有生物固氮、降解甲苯和倍硫磷等特性的细菌序列相似性较高或进化关系较近,推测其在免耕土壤肥力、有毒物质降解及有机质转变等过程中起作用。

Bacterial population diversity in no-tillage and tillage soils were analyzed by PCR-denaturing gradient gel electrophoresis（DGGE） to get the information on dominant bacteria.The metagenomics technologies were employed to obtain the total DNA,then 16S rDNA V3 region was amplified by PCR.Soil microbial richness was analyzed by 16S rDNA V3-PCR-DGGE.Technologies of cloning and sequencing combined with a phylogeny tree were applied to analyze the evolutional relationship of genes corresponding to several interesting bands involved in this research.The results of DGGE analysis showed that the bacterial population diversity of no-tillage soil was more abundant than that of tillage soils and the UPGMA cluster analysis exhibited a significantly different community composition between no-tillage and tillage soils,demonstrating that the soil tillage system had a remarkable effect on the bacterial communities.Phylogenetic analysis exhibited the distinctive populations specific in no-tillage soil were close to the bacterium chracterized by azotification,methylbenzene and baycid degradation in genetic evolution,suggesting that these distinctive populations may have played a significant role in fertility change,metabolism and conversion of organic matters in no-tillage soil.