Production and physicochemical properties of recombinant Lactobacillus plantarum tannase

Tannase is an enzyme with important biotechnological applications in the food industry. Previous studies have identified the tannase encoding gene in Lactobacillus plantarum and also have reported the description of the purification of recombinant L. plantarum tannase through a protocol involving several chromatographic steps. Here, we describe the high-yield production of pure recombinant tannase (17 mg/L) by a one-step affinity procedure. The purified recombinant tannase exhibits optimal activity at pH 7 and 40 degrees C. Addition of Ca(2+) to the reaction mixture greatly increased tannase activity. The enzymatic activity of tannase was assayed against 18 simple phenolic acid esters. Only esters derived from gallic acid and protocatechuic acid were hydrolyzed. In addition, tannase activity was also assayed against the tannins tannic acid, gallocatechin gallate, and epigallocatechin gallate. Despite L. plantarum tannase representing a novel family of tannases, which shows no significant similarity to tannases from fungal sources, both families of enzymes shared similar substrate specificity range. The physicochemical characteristics exhibited by L. plantarum recombinant tannase make it an adequate alternative to the currently used fungal tannases.