title: metagenomic
design: In brief, the fragmented DNAs were combined with End Repair Mix, and purified with QIAquick PCR Purification Kit (QIAGEN, Germany), then A-Tailing Mix was added. The purified Adenylate 3-Ends DNA was combined Adapter and Ligation Mix. Several rounds of PCR amplification with PCR Primer Cocktail and PCR Master Mix were performed to enrich the Adapter-ligated DNA fragments. Finally, PCR amplification was carried out and PCR products were purified with AMPURE XP beads to obtain the final library.