title: metagenome: environment
design: Sequencing libraries were generated using NEB Next Ultra DNA Library Prep Kit for Illumina (NewEngland Biolabs, MA, USA) following manufacturer's recommendations and index codes were added. Thelibrary quality was assessed on the Qubit 3.0 Fluorometer (Life Technologies, Grand Island, NY) and Agilent4200 (Agilent, Santa Clara, CA) system. At last, the library was sequenced on an Illumina Hiseq X-ten platformand 150 bp paired-end reads were generated.