Isolation and Identification of High Biomass and Lipid Productivity Euglena Strain from Tropical Malaysian Environments for Enhancement of Biofuel Production

Abstract

The microalgae Euglena holds promise for biofuel production due to its high lipid content. However, the lipid productivity of current species/strains for biofuel production remains suboptimal due to limitations in strain selection. Therefore, this study aims to isolate and identify novel Euglena species or strains with high biomass and lipid productivity to enhance biofuel production from a desirable environment. Malaysia’s tropical climate with abundant sunlight and water resources provides an ideal environment for microalgae cultivation. Therefore, this research is conducted in Malaysia for effective utilization. Accordingly, water samples were collected from various Raja Musa Forest Reserve habitats in Selangor, Malaysia including peatland, paddy fields and the Kuala Selangor River. The samples were isolated using the single-cell pickup technique. The isolated samples were cultivated using the test tube system. The biomass and lipid productivity were quantified using the gravimetric technique. The top novel lipid-producing Euglena strain SAB-3 was identified through scanning light microscopy and phylogenetic analysis of the ITS2 region. The Sab-3 was placed within the Euglena gracilis clade through this analysis, showing close similarity to the E. gracilis SAG strain. SAB-3 dominated high biomass productivity (0.704  g L¹ day¹), high lipid productivity (0.051 g L¹ day¹) and relatively high specific growth rate (1.091 day¹) with a shorter cultivation time of 7 days compared to the E. gracilis (NIES-48).