Tannin acyl hydrolase (E.C: 3.1.1.20) or tannase is an enzyme which hydrolyses ester and depside bonds of hydrolysable tannins releasing gallic acid and glucose. Tannase is an extracellular, inducible enzyme, produced by fungi, bacteria and yeast. The tannase is produced by solid-state, liquid surface and submerged fermentation. The solid-state fermentation offers a number of advantages over submerged and liquid conventional fermentation for the enzimes production. The production is simple, using vegetable residues such as coffee wastes, grape, cashew or by-products as wheat bran, rice or oats, to which tannic acid is added. The use of residues is an alternative to solve pollution problems that can be caused by an incorrect environmental disposal. Tannase enzyme has several applications on food, juices and pharmaceutical industries. The objective of this work was to select tannase producing fungi and to study the production of this enzyme in vegetable residues rich in tannin. The first stage of the selection was carried in solid-state fermentation using as substrate wheat bran supplemented with 0.5% of tannic acid. Among the 400 tested lineages, 6.75% of the fungi produced the enzyme. The lineages that showed the best activities were LAB345G, LAB53G and LAB153G, with 0.3862, 0.2149 and 0.1848 U activities values, respectively these lineages were tested in vegetables residues as coffee and grape, adding 0.5 and 1.5% of tannic acid in the fermentation environment. The best result was obtained using LA153G and coffee residues, with an activity of 0.275U being observed.
screening; tannase; residues; tannin
