bacterioplankton community
DNA extraction was performed following the DNAeasy PowerSoil Pro kit (Qiagen, Germany) manufacturers protocol. To describe bacterial diversity the 16S rRNA gene V3-V4 region was amplified with the primers 341F (CCTACGGGNGGCWGCAG) and 785R (GACTACHVGGGTATCTAATCC; Klindworth et al., 2013). DNA samples were sequenced on an Illumina MiSeq 2 X 300 (approximate sequencing depth: 50K reads/sample) by a GENEWIZTM platform (South Plainfield, NJ, USA).