Metagenomic DNA Extraction Protocol

DNA extraction was performed using lysozyme (1 mg/ml) for 1 h at 37°C, as previously described [25 (link)]. Then proteinase K (0.2 mg/ml) and 1% sodium dodecyl sulfate (SDS) were added, and the samples were incubated at 55°C for 60 min with gentle agitation. The lysate was rinsed into a new tube with 1 ml SET buffer. Metagenomic DNA was extracted with one volume of phenol:chloroform:isoamyl alcohol (25:24:1) and then precipitated with ethanol and sodium acetate (0.3 M final concentration) at -20°C overnight. The DNA was purified using a Power Clean DNA Clean-Up Kit (MO BIO Laboratories) and stored at -20°C.