A NEWLY SELECTED LIPID-RICH MICROALGAE STRAIN AND ITS MOLECULAR IDENTIFICATION

Ten pre-selected microalgae were cultivated in a bubble column photobioreactor, and tested for their lipid production potential using lipid productivity as a key characteristic. The results showed that their biomass dry weights and total lipid contents ranged from 0.8 g/L to 1.6 g/L and 14.8% to 39.7%, respectively. Six strains of all investigated species had lipid productivity greater than 30 mg/(Ld). The strain HY-6, which had the highest lipid productivity 50.8 mg/(Ld), can be a candidate species for biodiesel production. Taxonomic evaluation of the strain HY-6 was performed on the basis of morphological observation and phylogenetic analyses of concatenated 18S ribosomal RNA gene and internal transcribed sequence. HY-6 was preliminarily identified to belong to either the genus Chlorella or Parachlorella on the basis of its morphological characteristics such as spherical single cell, one well-defined pyrenoid and cup-shaped chloroplast. Phylogenetic analyses of 18S rDNA and ITS of coccoid green algae within the Chlorella and the Parachlorella clades of Chlorellaceae further identified HY-6 as Parachlorella kessleri.