title: sequences of bacteria
design: The diversity of bacterial plankton was determined by analyzing the V4-V5 hypervariable regions of the 16S rRNA gene, which was amplified with the primer set 515F (50-GTGCCAGCMGCCGCGGTAA-30) and 907R (50-CCGTCAATTCMTTTRAGTTT-30) by thermocycler PCR system (GeneAmp 9700, ABI, USA).