bacterioplankton communities in the Danjiangkou Reservoir

A total of 35 surface-water samples (seven replicates for each sample) were collected from the Danjiangkou Reservoir on May 1, 2016. Large plankton were removed by filtering through a 20-μm membrane filter, and bacterioplankton were collected by filtering through a 0.22-μm-diameter filter. The genomic DNA of bacterioplankton was extracted from the stored filters using the E.Z.N.A.® Water DNA Kit (OMEGA, USA) according to the manufacturer's instructions. Electrophoresis and a NanoDrop ND 2000 (Thermo Scientific, USA) were used to examine the quantity of the extracted DNA. The V3-V4 region of the bacterial 16S rRNA gene was amplified using 338F and 806R with sample-identifying barcodes.High-throughput sequencing (Illumina MiSeq PE300 platform, Illumina, USA) was performed by Shanghai Majorbio Bio-Pharm Technology Co., Ltd. (Shanghai, China).