title: Bacterial community of seawater
design: Sampling campaign was performed to identify major bacterial taxa responsible for initial biofilm formation on artificial surfaces in the Southern coastal seawater of India. From same geographical location, the bacterial biomass of both planktonic (seawater) and surface assemblages (attached on artificial surfaces), immersed for 72 hours in the intake area of a coastal nuclear power plant was concentrated on 0.22-micrometer filter paper and stored at -20C  until further processing. Metagenomic DNA isolation was done using PowerWater DNA Isolation Kit (MoBio Laboratories Inc., USA) following the manufacturer's instructions. DNA from three independent extractions was combined for each sample and their quality was measured by picogreen (Invitrogen) using Victor 3 fluorometry. Total extracted DNA was used for amplification of hypervariable V3-V4 region of 16S rDNA using barcoded universal bacterial primers. The products of replicate PCRs were pooled for each sample, confirmed on agarose gel and were extracted from the gel using QIAquick PCR Purification kit. The size and quality of prepared library were validated by running on a Bioanalyzer 2100 (Agilent Technologies, California, US) using a DNA 1000 chip. PCR products with unique indices were taken in equal quantities and were paired-end (300x2 bp) sequenced on an Illumina MiSeq platform at Macrogen Inc. (Seoul, Korea).
library_name: SU_SW