PCR-RFLP analysis of bacterial 16S rDNA from a typical garden soil in Taihu region
太湖地区典型菜地土壤微生物16S rDNA的PCR-RFLP分析

Soil microbial diversity provides basic function of a soil ecosystem. In this study, the total DNA of microorganisms was extracted by an indirect method from a typical garden soil of Taihu region, Jiangsu Province. The 16S rDNAs of the extracted DNA were amplified using bacterial universal primers 27F and 1492R. PCR products were ligated into the pMD 18-T Vector and transformed into Escherichia coli DH5 to construct a 16S rDNA clone library of the soil microbes. A total of 173 clones from the library were screened and their 16S rDNA fragments were reamplified. The PCR products were digested by Rsa I and Hha I, re- spectively, and their fingerprints were analyzed. The results indicated that the library includes 63 Hha I and Rsa I restriction endonuclease types and the coverage (C value) of the clone library is 76.30%. The number of genotypes digested either by Hha I or Rsa I is only 40 and 27 although it has a high coverage. There were two main restriction types accounting for 16% and 12% of the total 16S rDNA clones, respectively. Phy- logenetic analysis suggests that the dominant bacteria in this garden soil belong to -proteobacteria and -proteobacteria.