Rapid and simple DNA extraction protocol from goat rumen digesta for metagenomic analysis

In contrast to the traditional culturing techniques and microscopy that have led to the identification and characterization of only about 15-20 % of the rumen microbes till date, nucleic acid-based molecular approaches are rapid, reproducible, and allow both the qualitative and quantitative assessment of microbial diversity. The aim of this study was to develop a simple, rapid and effective extraction protocol for the recovery of high-molecular-weight and cloneable metagenomic DNA (mDNA) from goat rumen contents. An efficient method was devised to isolate high-molecular-weight mDNA (>23kb) that was pure and cloneable after isolation in a relatively short period (3.5 h). This is the first report wherein purification of isolated mDNA could be passed. The purity and cloneability of mDNA was found to be possible with the successful restriction digestion, 16S rDNA PCR amplification of the isolated mDNA and mDNA library construction.The screening of 1600 clones from the metagenomic library revealed one clone with adistinct hydrolytic activity on carboxymethyl cellulose (CMC) agar suggesting its endoglucanase activity. Agarose gel electrophoresis showed aDNA insert of ~1.5kb size on digestion with BamH1. The metagenomic clones offer a prodigious non-conventional means to explore the genetically untapped resources from nature.