Applied Biochemistry and Biotechnology, Vol.182, No.1, 382-399, 2017
Isolation, Identification and High-Throughput Screening of Neutral Lipid Producing Indigenous Microalgae from South African Aquatic Habitats
Exploring indigenous microalgae capable of producing significant amounts of neutral lipids through high-throughput screening is crucial for sustainable biodiesel production. In this study, 31 indigenous microalgal strains were isolated from diverse aquatic habitats in KwaZulu-Natal, South Africa. Eight superior lipid-producing strains were selected for further analysis, based on Nile red fluorescence microscopy screening. The microalgal isolates were identified to belong to the genera Chlorella, Neochloris and Chlamydomonas via morpho-taxonomic and molecular approach by 18S rRNA gene sequencing. Chlorella vulgaris PH2 had the highest specific growth rate (mu) and lowest doubling time of 0.24 day(-1) and 2.89 +/- 0.05 day(-1), respectively. Chlorella vulgaris T4 had the highest biomass productivity of 35.71 +/- 0.03 mg L(-1)day(-1). Chlorella vulgaris PH2 had the highest lipid content of 34.28 +/- 0.47 and 38 +/- 9.2% (dcw) as determined by gravimetric analysis and the sulfo-phospho-vanillin (SPV) method, respectively. Chlorella vulgaris PH2 exhibited a high content of saturated fatty acids, while Chlorella sp. T4 exhibited a high total content of saturated and monounsaturated fatty acids with a low content of polyunsaturated fatty acids. The preponderance of neutral lipids suggests that Chlorella sp. T4 is a suitable candidate for biomass feedstock for biodiesel production.
Keywords:Biodiesel;Bioprospect;Chlorella sp.;Indigenous;Fatty acid methyl esters;GC-MS;Lipid profile;Microalgae