Rhizomucor miehei Lipase Immobilized on Macroporous Resin and its Application in Biodiesel Synthesis

Abstract

In order to achieve the industrialization of lipase-catalyzed biodiesel production, economic and effective carriers for immobilized lipase need to be exploited. In this study, Rhizomucor miehei lipase (RML) was immobilized on different kinds of macroporous resins and NKA was found to be the best carrier. The immobilized RML was then employed to catalyze biodiesel production from soybean oil. 8 different organic solvents were used as media in the trans-esterification reactions. Isooctane was proved to be the optimal one. Subsequently, immobilization conditions and reaction conditions were further optimized through single factorial experiments and response surface methodology (RSM). Results were as follows: the recovery activity of the immobilized RML was up to 1531.7%; the corresponding specific activity could reach 73761.99 U/g protein, almost 15 fold than that of the free RML; the biodiesel yield attained 99.2% under the optimal conditions in isooctane system; the immobilized lipase can yield 64% product after being run for 4 cycles, much better than the commercial immobilized lipase, Lipozyme RM IM (remains only 31%). In conclusion, NKA is a promising carrier for the immobilization of RML and exhibits a good performance in biodiesel production compared with Lipozyme RM IM.