Water sample collected from Cochin Estuary, South west cost of India
Whole genome sequencing (WGS) libraries were prepared with Illumina-compatible NEXTflex Rapid DNA sequencing kit (BIOO Scientific, Austin, Texas, U.S.A.) at Genotypic Technology Pvt. Ltd., Bangalore, India. Briefly, genomic DNA was sheared using Covaris S2 sonicator (Covaris, Woburn, Massachusetts, USA) to generate approx. fragment size distribution from 200 bp to 400 bp. Here, the fragment size distribution was checked on Agilent Bioanalyzer and subsequently purified using AmPure magnetic beads (Agencourt). Purified fragments were end-repaired, adenylated and ligated to Illumina multiplex barcode adaptors as per NEXTFlex Rapid DNA sequencing kit protocol. Adapter-ligated DNA was purified and size selected using Ampure beads. Resultant fragments were amplified for 4 cycles of PCR using Illumina-compatible primers provided in the NEXTFlex Rapid DNA sequencing kit. Final PCR product (sequencing library) was purified with Ampure beads, followed by library quality control check. Illumina-compatible sequencing library was initially quantified by Qubit fluorometer (Thermo Fisher Scientific, MA, USA) and its fragment size distribution was analyzed on Agilent TapeStation.