Biomass yield and biochemical profile of fourteen species of fast-growing green algae from eutrophic bloomed freshwaters of Kerala, South India

Abstract

Eutrophic, bloomed waters are known for fast-growing microalgae of high biomass yield. The biochemical composition of algae may vary from species to species. Identification of fast-growing local algal species, their experimental culture for assessing biomass yield and biochemical screening of the same for desirable metabolites is crucial to the prospects of algal technology. The freshwater algal diversity of Kerala - one of the biodiversity hotspots of the world, remains poorly explored. In this context, we assessed the yield and biochemical profile of hitherto uninvestigated 14 fast-growing microalgae of eutrophic bloomed freshwaters of Kerala. The biomass yield, carbohydrate, protein, pigment and lipid content of these species were significantly different. The alga Pseudococcomyxa simplex showed the highest biomass yield of 196.5 ± 3.04% increase L−1 day−1. The alga Kirchnerialla lunaris with 58.95% protein was found superior to the other algae in this regard. The species Scenedesmus obliquus was significantly higher in total lipids (32.05% of dry biomass) than the other algae. The alga Monoraphidium griffithii with 42.92% of omega groups of fatty acids in its lipid appeared a highly valuable species. The algae, Radiococcus nimbatus (12.77 ± 2.31 mg g−1 of chlorophyll a), Myrmecia bisecta (5.87 ± 0.01 mg g−1 of chlorophyll b) and Monoraphidium griffithi (7.50 ± 0.02 mg g−1 carotenoid) appeared superior to the others in pigment content. Fourier-Transform-Infrared Spectroscopy of the biodiesel prepared from the lipids of all the algae confirmed the biodiesel feasibility of the same. The bioresource potentials of the 14 algal species revealed are new to science.