Synthesis of propyl gallate by transesterification of tannic acid in aqueous media catalysed by immobilised derivatives of tannase from Lactobacillus plantarum.

Immobilised derivatives of tannase from Lactobacillus plantarum were able to catalyse the transesterification of tannic acid by using moderate concentrations of 1-propanol in aqueous media. Transesterification of tannic acid was very similar to transesterification of methyl gallate. The synthetic yield depended on the pH and concentration of 1-propanol, although it did not vary much when using 30% or 50% 1-propanol.

Improvement of enzyme properties with a two-step immobilizaton process on novel heterofunctional supports.

Novel heterofunctional glyoxyl-agarose supports were prepared. These supports contain a high concentration of groups (such as quaternary ammonium groups, carboxyl groups, and metal chelates) that are capable of adsorbing proteins, physically or chemically, at neutral pH as well as a high concentration of glyoxyl groups that are unable to immobilize covalently proteins at neutral pH. By using these supports, a two-step immobilization protocol was developed.