[Comparison of total microbial DNA extraction methods from solid-culture of Zhenjiang vinegar].

OBJECTIVE:To analyze the diversity and succession of microbes during traditional solid-state fermentation. Taking Zhenjiang vinegar for example, we compared 11 methods for extracting genomic DNA from microbes in solid-culture of Zhenjiang vinegar. METHODS:The yield and purity of the DNA were measured by ultraviolet spectrophotometer and real-time PCR. The bacterial and fungal diversity during solid-state fermentation was analyzed by denaturing gradient gel electrophoresis (DGGE). RESULTS:The highest extraction yield of total DNA was 93.2 +/- 1.5 microg/g dried culture. The quantity of bacteria and fungi reached to the maximum of 1.73 x 10(13) copies x (gram dried culture)(-1) and 6.49 x 10(12) copies x (gram dried culture)(-1), respectively. The community patterns revealed by DGGE were noticeably influenced by the DNA extraction methods. Hereinto, six methods of SDS-based DNA extraction resulted in the larger number of DNA bands. CONCLUSION:The results showed that the most effective method was SDS high salt extraction combined with grinding in liquid nitrogen and lysozyme lysis.