Degradation of tannic acid and purification and characterization of tannase from Enterococcus faecalis

Tannins, present in various foods, feeds and forages, have anti-nutritional activity; however, presence of tannase in microorganisms inhabiting rumen and gastrointestinal tract of animals results in detoxification of these tannins. The present investigation was carried out to study the degradation profile of tannins by Enterococcus faecalis and to purify tannase. E. faecalis was observed to degrade tannic acid (1.0% in minimal media) to gallic acid, pyrogallol and resorcinol. Tannase from E. faecalis was purified up to 18.7 folds, with a recovery of 41.7%, using ammonium sulphate precipitation, followed by DEAE-cellulose and Sephadex G-150. The 45 kDa protein had an optimum activity at 40 °C and pH 6.0 at substrate concentration of 0.25 mM methyl gallate.