In this dissertation,studies on the enzymatic hydrolysis of tannic acid and qunic acid extracted from Tala tannin in aqueous media and tannase-producing conditions and optimal fermentation parmeters was reported by using Penicillium tannase. Gallic acid is one of important industrial chemicals, and has been used widely and large in amount,becoming now a sold-well commercial in market. Today gallic acid is almost produced from acidic hydrolysis of tannic acid from Chinese gallotannin. But this method has som...