Combination of <i>Mucor circinelloides</i> and <i>Penicillium camemberti</i> Whole-Cell Biocatalysts for One-Step Biodiesel Production
Shulan Ji, Rui Xu, Yu Zhang, Xun Li, Fei Wang
Abstract
Accumulation of partial glycerides, such as monoglycerides (MG) and diglycerides (DG), is one of the rate-limiting steps in the transesterification of woody oil catalyzed by Mucor circinelloides producing triacylglycerol lipase. To efficiently convert partial glycerides into the corresponding methyl esters (MEs), Penicillium camemberti, which produces mono- and diacylglycerol lipase (MDGL), was utilized. Considering the cost-effectiveness, M. circinelloides and P. camemberti were immobilized within loofah sponges and polyurethane foam and directly employed as whole-cell biocatalysts. Optimal conditions for one-step biodiesel production from Cornus wilsoniana fruit oil using the combined biocatalysts were determined as follows: methanol/oil ratio of 4:1, water content 40%, temperature 40 °C, and biocatalyst dosage 10% (weight mixing ratio of 4:1). Under these conditions, the biodiesel yield was 98% at 15 h. Moreover, through the repeated recycling of combined biocatalysts, the biodiesel yield could be maintained at 75% after six reuses. These results suggest that the combination of biocatalysts with different specificities for the transesterification of complex lipid substrates is a potentially effective strategy for biodiesel production.