Tannins are present in many plant foods. Tannase (EC 3.1.1.20) catalyses hydrolysis of ester bonds in hydrolysable gallotannins releasing glucose and gallic acid. Enzyme was produced by Penicillium chrysogenum cultured in Czapek-Dox medium containing tannic acid. The tannic acid was used as a substrate in the enzymatic reactions. The product inhibits the enzymatic reaction. It was determined that inhibition was of the competitive type. The mathematical model (Eg. 7) and kinetic constancy describing the process were determined: KM=0,5310-4[mol/dm3], RM=1,2610-3 [mol/dm3 min], KP=2,0410-4 [mol/dm3]. The results obtained from the model well agree with those obtained experimentally.
Tannins as compounds of plant biomass seem to be a very useful raw material for an effective bioconversion. This is due to their abundance and renewability as well as the possibility of producing various chemicals and curative preparations from this source. On the other hand, enzymatic removal of tannins from agricultural feedstocks by tannase is very important for production of digestible feed and food products, clarified beverages and fruit juices or instant tea. This article presents a review of information on tannins and their hydrolysis by microbial tannase. Special attention has been paid to chemical structure of tannins and their negative or positive effects on organisms as well as the production of tannase and its biochemical properties. Most promising prospects for the practical applications of tannase in food, pharmaceutical, cosmetic and leather industries are also discussed.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.