RNA-Seq of water
Random amplification of nucleic acids was carried out using SuperScript III reverse transcriptase (Invitrogen, USA) and primer-A (5'-GTTTCCCAGTAGGTCTCNNNNNNNNN-3'). Double stranded DNA was generated by two rounds of synthesis with Sequenase 2.0 (USB, USA), followed by amplification with Phusion DNA polymerase using primer-B (5'-GTTTCCCAGTAGGTCTC-3')