Tannase (EC 3.1.1.20) is a hydrolytic enzyme involved in the biodegradation of tannins. This enzyme catalyzes the hydrolysis of the ester and depside bonds present in hydrolysable tannins, releasing gallic acid and glucose [1]. Tannase also has many applications in food, bev- erage, pharmaceutical and chemical industries, and even in bioremediation [2,3]. Industrial bioconversion of tan- nic acid is generally accomplished by tannase for the production of gallic acid, which is mostly used in the pharmaceutical industry to produce the anti-bacterial drug Trimethoprim [4]. Gallic acid is also an important substrate for the synthesis of propyl gallate, an antioxi- dant used in the food industry [1].
Microorganisms can continuously produce tannase in large quantities, resulting in an increased yield with the establishment of optimized fermentation methods. Tan- nase is produced in the presence of tannic acid by several filamentous fungi, mainly Aspergillus and Penicillium species [4]. Industrial production of microbial tannase is obtained by submerged culture because this simplifies sterilization and process control [5]. Studies evaluating the choosing strains and enzymes with desirable charac- cultivation of tannase-producing strains are important for
144
teristics for industrial applications. The optimization of enzyme production is an important step that can be per- formed by individually optimizing each parameter (tem- perature, cultivation time and pH, among others), as has been done for Aspergillus flavus tannase production [6], or by using the factorial design methodology, as has been done for Bacillus massiliensis tannase production [7]. This article describes the optimization of tannase produc- tion under submerged fermentation by Aspergillus sp. GM4, a new strain producer, using the Response Surface