Biochemical parameters and 18S rRNA gene sequence analysis amongst green microalgal strains from selected aquatic...

In the present study, 24 green microalgae strains were isolated from selected aquatic sites of India. These were microscopically identified as Chlamydomonas sp., Scenedesmus sp., Chlorella sp., Dictyosphaerium sp. and Dunaliella sp. Nannochloropsis sp. (MCC 25), was used as a reference strain. Results showed that Dictyosphaerium sp. (MCC 10 and MCC 12) showed relatively higher nutritive content. The total soluble proteins in the reference strain was 21.4%, whereas it showed carbohydrate content of 17.2% and the lipids were 3.4% on a dry weight basis. Best performing strains were identified by biochemical characterization. Five genera were selected for molecular identification since they were the most representative based upon their area of isolation and their optimum content of total soluble proteins, carbohydrates and lipids. 18S rRNA sequencing authenticated their identification as Scenedesmus sp., Dictyosphaerium sp. and Chlorella sp. The sequences of these have been submitted in NCBI database with accession numbers as KT808247-KT808251. The correlation matrix showed positive correlation between carbohydrates and lipids, while negative correlation was seen between proteins and carbohydrates and between proteins and lipids. This study emphasizes the need for complete compositional analysis of the biomass for the possible applicability in the area of value addition.