Development of a tannase biocatalyst based on bio-imprinting for the production of propyl gallate by transesterification in organic media

A bio-imprinting technique was applied to activate tannase in order to enhance its biocatalytic activity. Specifically, the effects of three bio-imprinting methods (i.e. substrate imprinting, pH imprinting, and interfacial imprinting) on the activating factor of tannase were investigated. The results show that bio-imprinting methods can activate tannase remarkably, and they were combined to develop a tannase biocatalyst with a 40% conversion rate of substrate, 100-fold higher than that of the control. This approach can be used to construct an effective way to produce propyl gallate as well as to exploit readily available tannic acid. The immobilized bio-imprinted tannase can catalyze the synthesis of propyl gallate from tannic acid by transesterification in organic media. This work not only presents an effective means of making use of various tannic acid-rich agro-forestry residues, but also broadens the field of applications of the bio-imprinting technique.