BioSample

The Caspian Sea is the world's largest enclosed body of water. The northern part of the Caspian sea is largely a freshwater habitat. Salinity increases gradually towards the middle part, and the southernmost part is a stable brackish ecosystem with 1.1% salinty (ca. one third of the open ocean). This biosample contains metagenomic data from depth profile of the Caspian. Briefly, 50L of water was collected from each depth and filtered serially through 20, 5 and 0.22 micron filters. This metagenome deposited here was obtained by sequencing (Illumina HiSeq) of the 0.22 micron fraction. After assembly and annotation Contigs were considered to belong to each phylum if a majority of genes gave best BLAST hits to that phylum. In each phylum contigs were grouped using taxonomy, principal component analysis of tetranucleotide frequencies, GC% and abundance profile in the metagenomes.