Selection of fungi of the genus Aspergillus tannase producers for inclusion in animal feed

Abstract

The biotechnology industry produces several enzymes with numerous uses, being able to be present in the food industry; drinks; pharmaceuticals as therapeutic agents or as an alternative to a fairly current issue such as reducing the impact on the environment as well as generating renewable resources. Agroindustry wastes that are disposable in the production process can be used in order to add value and / or propitiate the use of them, and can be used in animal feed. Tannase (Tannin-acylhydrolase) is an enzyme that hydrolyzes esters and side bonds of hydrolysable tannins, such as tannic acid, promoting the release of glucose and gallic acid. This enzyme can be obtained from vegetable, animal and microbial sources, being present in greater concentration in vegetable parts rich in tannins (fruits, leaves, twigs and peels). For the production of this enzyme a simple culture medium may be used, such as agroindustry by-products, such as grape rind, cashew, coffee or wheat bran, rice and oats, plus tannic acid. In the present work were selected species of fungi of the genus Aspergillus for the production of tanase. These being grown in modified medium; thus indicating the production capacity of tannase by them and the possible best producers of the enzyme. 19 fungi were tested, of which only 4 (A. caespitosus URM 5182, A. janus URM 4456 A. levels URM 2803 and A. sydowi URM 3066) did not show growth in the modified medium (increased with tannic acid). The species that most stood out for the growth in the medium screening tanase were the species Aspergillus japonicus and Aspergillus niger showing a growth in the colonies superior to the others selected.