Paired WGS Illumina run
Frozen stromatolites samples were lyophilized and homogenized, and the powder was processed as reported in Farías et al. (2013). Three replicate extractions were pooled and sequenced. DNA was sheared by sonication to fragment sizes of around 240 bp, cleaned (Zymo Research) and universal sequencing adaptors were ligated. After library quantification at a Qubit (Invitrogen), a 10 nmol stock solution of the amplified library was created. Sequencing-by-synthesis was performed on an Illumina Genome Analyzer (GAIIx). Two lanes of 36 bp single reads and one lane with 120 bp paired-end reads were run.