Metaviriome of the Mediterranean Deep Chlorophyll Maximum
Metaviriome sampling, construction, sequencing and assembly:   Seawater (20 L) collected from the DCM of the Mediterranean Sea in August of 2011   from a depth of 65m was filtered through a 0.2 µm filter (GVWP2932A).   Subsequently, phages were concentrated using tangential flow filtration (TFF)   with a 30 kD polyethersulfone membrane from Vivaflow (VF20P2). The resulting phage   concentrate was ultracentrifuged (Optima XL 1000K Ultracentrifuge, Beckman) for 1 h   at 4 °C using a Type 70 Ti rotor (Beckman) at 30,000 rpm (92,600 g). The pellet was   resuspended in 1 mL of the seawater supernatant and treated with 2.5 units DNase I   at 37 °C for 1 hr and 70 °C for 10 min to remove bacterial DNA. The phages were then   lysed in 0.50 mg/mL Proteinase K and 1.0% SDS at 56 °C for 1 h followed by two rounds   of phenol/chloroform/isoamyl alcohol extraction. The aqueous phase was then choloform/isoamyl   alcohol extracted and ethanol precipitated and resuspended in sterile water. DNA quantity and   quality was determined using gel electrophoresis and Picogreen.  Multiple amplification   displacement (Illustra GenomiPhi V2 DNA Amplification Kit, GE Healthcare) was performed   using ca. 30 ng of DNA for each of five reactions. The resulting DNA (ca. 5 µg) was sequenced   in one third of an Illumina lane, yielding approximately 18GB of sequenced data (paired end   reads, 300bp) with a total of ~180 million reads.