Evaluation of Several DNA Extraction Methods for Obtaining Total Community DNA from Anaerobic Digestion Sludge

Abstract

In order to develop and establish an effective method for extraction of total genomic DNA from anaerobic digestion sludge, the DNA extraction methods consisted of enzymatic-disruption method, physical–chemical method, and Mp- Bio method were used to extract DNA from anaerobic digestion sludge samples and compared with in terms of the efficient cell lysis, DNA yield, purity and molecular analyses. The results showed that total genome DNA could be extracted from anaerobic digestion sludge by all the three methods. However, the enzymatic method had better DNA yields, cell lysis efficiency and lower humic acids and expensive than other DNA extraction methods. Total DNA was purified by spin-bind cartridge after being precipitated by PEG8000, the humic acids content was reduced by 96% during the purification steps, and the DNA recovery efficiencies were high and similar each other, which were about 88%. A eubacterial 16S rRNA gene-targeted primer pair was used for PCR polymerase chain reaction to amplify a region of the 16S rRNA to check the purity of the purified sample. Results indicated that nearly full length 16S rDNAs were amplified from all the purified DNA samples, and all the amplification products could be digested by the restriction enzymes HhaI and HaeIII. All of these above indicated that the enzymatic-disruption method is the best method to obtained genome DNA from anaerobic digestion sludge.