title: Metagenome analysis of BTEX contaminated hypoxic groundwater
design: DNA quality and quantity measurements were performed on Bioanalyzer (Agilent Technologies) and Qubit (Life Technologies). Total metagenome DNA samples (each pooled using three replicates) were processed using the Ion Xpress™ Plus Fragment Library Kit (Life Technologies), according to the manufacturers suggestions. Briefly, 1 ug of metagenome DNA was fragmented for each sample, the 200-350 nt fraction was size selected, sequencing adaptors were ligated. The DNA fragment library was purified with PureLink PCR Purification Kit (Life Technologies) and size-selected on a 2% E-Gel. The 200-350 nt DNA fraction was amplified using Platinum PCR Supermix polymerase. Concentration of each library was determined using the Ion Library Taqman qPCR quantitation Kit (Life Technologies). Each library was clonally amplified by emulsion PCR (ePCR) using the IonXpress Template 200 ePCR kit. Emulsions were broken with buthanol, ePCR beads enriched for template-positive beads by hybridization with magnetic enrichment beads. Beads with the clonally amplified DNA were deposited onto sequencing Ion 318 chip and the barcoded samples were sequenced on Ion Torrent Personal Genome Machine™ using the 200-base sequencing chemistry.