Evaluating the potential of green alga Chlorella sp. for high biomass and lipid production in biodiesel viewpoint

Abstract

Abstract The present study assessed the potential of green alga Chlorella sp. for maximal biomass and lipid production in biodiesel aspect. Initially, growth of the tested strain was analyzed in terms of dry cell weight, optical density and then, lipid content, lipid yield and fatty acid composition were studied. The growth profile study was carried out from 0th day to 20th day of cultivation to find an optimal day for harvesting the biomass. The potential microalga Chlorella sp. was found to yield maximum biomass at about 1.1 g/L and cell density of 2.0 optical density on 16th day of growth. Further, in this study, bioprospecting of Chlorella sp. showed a lipid content of 11.5% on 16th day in standard medium without carbon dioxide purging and mechanical stirring. Adding to that, cells harvested from log and stationary growth showed same lipid content of 11.5%, whereas culture harvested from lag phase was found to reveal a marginally less lipid content of 10.5%. Further, the lipid yield was estimated from the test strain Chlorella sp. grown under log and stationary phases. Based on the data, it is observed that the total lipid of the strain grown under both the phases was found to yield similar lipid of 0.11 g/L, which substantiates the lipid content of the strain. Fatty acid profile analysis of the tested strain indicates the presence of major fatty acids such as palmitic, palmitoleic, oleic, and linolenic acid. With this in view, the Chlorella sp. was foreseen to be a potential feedstock for biodiesel production considering cell density, dry cell weight, lipid content, lipid yield and fatty acid composition at ambient condition.