Discovery of a new species of Heterococcus and analysis of its lifecycle, genome, and lipid production

Abstract

A new species of Xanthophyceae, Heterococcus coloradii, was discovered among snow fields in the Rocky Mountains. Axenic cultures of H. coloradii were prepared, and their cellular morphology, growth, and accumulation of lipids were characterized. H. coloradii was found to grow at temperatures approaching freezing and to accumulate large intracellular stores of lipids. Of particular interest was the accumulation of several long-chain polyunsaturated fatty acids known to be important for human nutrition such as eicosapentaenoic acid and palmitoleic acid. Algae that accumulate lipids in this manner have potential uses as sources of biofuels and poly-unsaturated fatty acids for human nutrition. In order to study H. coloradii's repertoire of genes, genomic DNA was extracted and sequenced with the Illumina GAIIx. 72 base-pair reads were organized into a draft genome of 170 mega base-pairs with 20x coverage. Over 20,000 unique protein hits were received with a MegaBLASTp using the translated draft genome as a query. Many genes were found that are involved in lipid metabolism and cold tolerance, thus highlighting the unique biology of H. coloradii.