Exploring the distinctiveness of biomass and biomolecules from limnic microalgae of unexplored waters of Noyyal River, Western Ghats, for exploitation.

Oleaginous microalgae with high biomass productivity, lipid content, and lipid productivity are desirable for sustainable biofuel production. Rapid and accurate quantification of lipid content facilitates the identification of promising microalgae candidates. In the present study, 23 freshwater microalgae species from river Noyyal were isolated and identified based on their morphological and molecular (18S rRNA) features and recorded as Karunya Algae Culture Collection (KACC). Their biomass and lipid content were characterized and screened using FT-IR, Nile red staining, and gravimetric method. Results generated from FT-IR spectra differentiated KACC microalgae based on their biochemical contents with Scenedesmus rubescens KACC 2 and Chlorococcum sp. KACC 13 possessed high total protein and lipid content, respectively. Nile red fluorescence at 530/575 nm showed the yellow fluorescence under a fluorescent microscope giving the evidence of high neutral lipids in 10 KACC microalgae isolates. Total lipid content showed prominent variation between the KACC isolates and found in the range of 4 to 32% of DW. Lipid productivity and biomass productivity showed a similar pattern among KACC strains. Thus, our findings serve as a baseline data on the bioprospecting potential of KACC isolates from river Noyyal, an unexplored area of Western Ghats.