Successive cycles of utilization of Novozym 435 in three different reaction systems

The main focus of this work was to investigate the residual esterification activity and the product conversion after 10 successive cycles of utilization of a commercial lipase in three systems: esterification of 2-ethyl hexanol and palmitic acid in a solvent-free system; esterification of ascorbic acid and palmitic acid in tert-butanol; and transesterification of glycerol and methyl benzoate in 2-propanol. These systems were chosen based on previous results by our research group in terms of product conversion. Before scale-up, there is a need for evaluating several cycles of utilization of the biocatalyst. The esterification of 2-ethyl hexanol showed that after 10 cycles the enzyme retained 90% of its activity. The system consisting of ascorbic acid, palmitic acid, Novozym 435 and tert-butanol showed that a reduction in enzyme activity was accompanied by a reduction in reaction conversion; the same behavior was not observed for the third system.