A newly isolated fungal strain used as whole-cell biocatalyst for biodiesel production from palm oil

A strain of Aspergillus niger isolated from atmospherically exposed bread and Jatropha curcas seed was utilized as a whole-cell biocatalyst for palm oil methanolysis to produce fatty acid methyl esters (FAME), or biodiesel. The A. niger strain had a lipase activity of 212.58 mU mL(-1) after 144 h incubation at 25 degrees C with an initial pH value of 6.5, using 7% polypeptone (w/w on basal medium) as the nitrogen source and 3% olive oil (w/w on basal medium) as a carbon source. The A. niger cells spontaneously immobilized within polyurethane biomass support particles (BSPs) during submerged fermentation. Thereafter, the methanolysis of palm oil was achieved via a three-step addition of methanol in the presence of BSPs-immobilized with A. niger cells. The influence of water content, reaction temperature and enzyme concentration on reaction rate was investigated. An 8% water content and a temperature of 40 degrees C in the presence of 30 immobilized BSPs, resulted in an 87% FAME yield after 72 h.