Application of 16S rDNA to Analyze Microbial Diversity in Sediment of Lake Taihu, China

摘要

Application of PCR to study microbial diversity of different deep sediments from Lake Taihu without cultivation, the 16S rDNA genes fragments were amplified by using two specific primers. The results of agarose gel (2%) electrophoresis show that the PCR products are about 626 bp and 234 bp in length. These amplified DNA fragments were separated by denaturing gradient gel electrophoresis (DGGE). Comparison of community structure analyses based on two primers revealed that the bacteria species are very abundant. In addition, the diversity indices change drastically throughout the layers, the diversity decreased with sediment depth. The composition of the numerically dominant bacterial populations and the physico-chemical characteristics of the sediment are very heterogeneous throughout the site. This result indicates that the diversity of bacteria decreases in association with sedimentation. The diversities of the bacterial communities are finely adapted to vertical gradients of physicochemical conditions were different. Five mutual major bands from 16S rDNA genes (V3 region) fragments DGGE profiles of sediment sample was eluted from gel, reamplified and sequenced. The results suggested that each band belonged to different DNA fragments with substantial sequence. Three of five sequences shared 95%—99% homology with unknown bacteria sequences in the database while the other two had 93% homology with unknown sequences in the database. At last, some advices were followed about the outcomes of two universal primers.