Fungus-Mediated Generation of Ethyl Ester Using Acid Oil as Substrate

摘要

Transesterification reaction of soybean acid oil was carried out by whole cell biocatalysis. The lipase production by Aspergillus sp. (RBD01) was optimized by modulating sources of nitrogen, pH of growth medium, and percentage of carbon source (acid oil). Soybean acid oil containing significant amount of free fatty acids (FFA) was hydrolyzed and transesterified using cell suspension and immobilized culture of Aspergillus sp. (RBD01) as catalysts. Complete hydrolysis of acid oil to free fatty acids was achieved by both forms (suspension and immobilized) of catalysts, within 12 h of the reaction time. Further, addition of ethanol resulted in conversion of FFA to ethyl ester to the extent of up to 72% in case of both immobilized and cell suspension. FFA and ethyl ester were quantified using ~1H NMR. The process of generation of ethyl esters through biocatalyzed transesterification of acid oils is thus observed to be a potential means of producing these products for diverse variety of industrial/commercial use such as biodiesel.