DNA extraction from activated sludge for metagenomic array

Abstract

In order to obtain probes of metagenomic array and construct genomic DNA library of activated sludge, highquality DNA should be prepared. Aiming to obtain the DNA, eight methods of extracting metagenomic DNA from activated sludge were compared based on DNA yield, purity, size, PCR and enzymatic digestion. As a result, the method of lysoenzyme-SDS-proteaseK-phenol/chloroform extration achieved high quality of DNA fragments without more purification steps, which means the high quantity, good purity and big size of DNA fragments. The gene of 16S rDNA and amoA could be amplified by PCR and the DNA from activated sludge could not be digested by EcoK I and HindIII, but SauAI. Therefore, the DNA need to be further purified by Agarose Gel DNA Purification Kit produced by Roche. Fig 7, Tab 3, Ref 14.