Bioprospecting autochthonous marine microalgae strain from the Arabian Gulf Seawater, Kuwait for biofuel feedstocks

Abstract

Bioprospection programs are the key to microalgal biotechnology for increasing the current portfolio of strains available for different biotechnological applications. In this work, nine fast-growing microalgae strains isolated from the Arabian/Persian Gulf coastal waters of Kuwait were evaluated for their potential as lipid protein feedstocks. The 18S rRNA gene sequencing revealed that the strains belong to 5 different genera, namely, Chlorella,Nannochloris, Scenedesmus, Tetraselmis, and Nannochloropsis. The total lipid content showed that the strains of Tetraselmissp. KUBS13G, and Tetraselmissp. KUBS16G strain displayed higher lipid content 29.56 % of dry weight; DW, and 26.13 % of DW, which were dominated by palmitic and oleic acids. Fuel properties calculated from the fatty acid methyl esters (FAMEs) by empirical equations were compared with EN14214 (European) and ASTM D6751−02 (American) biodiesel standards. Multicriteria decision aid (MCDA) method, Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), and Graphical Analysis for Interactive Assistance (GAIA) were used to select the suitable microalgae for biofuel feedstock based on their biodiesel fuel properties. Overall results suggest that the indigenous microalgae, Tetraselmis strain in particular Tetraselmis sp. KUBS37G, and Scenedesmussp. KUBS17R are the most suitable strain for biofuel feedstock, owing to the improved fuel properties, such as (0.88 g cm−3), low kinematic viscosity (3.1 mm2s−1), cetane number (54, 56), oxidation stability (14.6 h, 14.8 h), and cold filter plugging point (1.0°C, -6.1°C) respectively.