Abstract

Biodiesel has been regarded as a biodegradable and non-polluting fuel. Enzymatic transesterification reaction for manufacturing biodiesel from vegetable oils with alcohol is an attractive approach. However, the cost of enzyme remains a barrier for its industrial implementation. The aim of this research was the screening of lipase-producing microorganisms and the studies of potential lipase-mediated biodiesel production using palm oil as substrate. A total of 360 strains of bacteria, yeasts and fungi were isolated and screened from the samples of oil-contaminated soil and waste water. Among all the screened microbes, the potential lipolytic bacterium, Staphylococcus warneri, unicellular yeast, Candida rugosa and filamentous fungus, Fusarium solani were selected because of their high specific activities. The lipase-producing conditions were subsequently optimized by using palm oil as an inducer and lipase activities were compared for both hydrolytic and synthetic catalysis. C. rugosa lipase, which exhibited the highest potential for catalyzing the biodiesel production, was further purified and immobilized on various hydrophobic supports. The catalysis of transesterification between methanol and palm oil by the C. rugosa immobilized lipases revealed that immobilized lipase fromC. rugosa on Sepabeads EC-OD was the most promising for further development as a biocatalyst for the application of enzyme-catalyzed biodiesel synthesis.

Key words: Screening, lipases, immobilization, biodiesel.