Comparison of extraction methods of activated sludge microbial DNA for PCR-DGGE analysis
应用于PCR-DGGE分析的活性污泥微生物总DNA提取方法比较

The aim of this study was to develop a method of extracting total microbial DNA from activated sludge for PCR-DGGE analysis. Five methods were used to extract total microbial DNA from activated sludge. The DNA purity, yield, fragment size, and microbial diversity reflected by DGGE technique were used to evaluate the extracted DNA. The results of UV absorbance and agarose gel electrophoresis showed that the yield of DNA extracted by the kit method was lowest among the five methods. There was no significant difference in the yield of DNA for the other four DNA extraction methods. In terms of the DNA purity, the kit method was the best one. Four DNA extraction methods could effectively lysis both bacterial and fungal cells except the high temperature lysis method for fungal cells. According to the DGGE analysis, more diverse bacterial communities were obtained with the DNA extracted by the high temperature lysis method, and more diverse fungal communities were obtained with the DNA extracted by the SDS lysis method. High temperature lysis method could be more suitable for bacterial PCR-DGGE analysis of activated sludge, while SDS lysis method could be more suitable for fungal PCR-DGGE analysis.