中国生物工程杂志

Methods for studying the population diversity of microorganism in activated sludge usually require enrichment of bacterial genome. The efficient information on microbial species composition provided and shifted in diversity revealed are dependent on the effective DNA recovery technique. The method was based on washing by alkaline phosphate buffer and digestion with extended heating of the activated sludge suspension in the presence of lysozyme and freeze-thawing in high-salt-SDS buffer. The extraction was tested for four activated sludge differing in places and dates. The DNA fragment from all sludge was integrity. DNA yields ranged from 105 to 823 μg/g sludge and were of sufficient purity for PCR-based 16S ribosomal DNA analysis and restriction digested. In general, all methods produced DNA pure were not enough for PCR amplification and libraries construction et al. As basis of experimental goals, this study provides an appropriate extraction method of microbial DNA in sludge.