Preservation_R3
Libraries were prepared using the Nextera XT DNA Library Preparation Kit (Illumina, USA) following the manufacturers instructions. First, metagenomic DNA was fragmented and tagged using the fragmentation process. Then, the tagged DNA was amplified using a limited-cycle PCR program to add adapters (index). Additionally, libraries were purified using 0.6x Agencourt AMPure XP beads (Beckman Coulter, USA). Finally, the libraries were quantified using the Qubit fluorometer (Invitrogen, Thermo Fisher Scientific) and sequenced in paired-end mode (2  150 bp) on the Illumina NextSeq 1000 platform.