The Tannase from red yeast Rhodotorula glutinis: purification and characterization

The tannase enzyme was successfully purified to homogeneity from the culture broth of red yeast strain Rhodotorula glutinis DB2 in a three-tandem step involving ultrafiltration (5 kDa and 100 kDa systems), Sephadex G-200 gel filtration chromatography, and DEAE Sepharose CL-4B anion exchange chromatography. The purified tannase appeared to be homogeneous on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The purified tannase had a specific activity of 3.33 U mg(-1), with a 1.3% recovery and overall purification of 302-fold. The molecular mass of the tannase estimated by SDS-PAGE was about 73 kDa. The tannase had an optimum pH of 6.0 and an optimum temperature of 40 degrees C. The most stable pH was 7.0, and the enzyme was stable up to 40 degrees C. One mmol L-1 of Fe3+, Sr2+, Na+, and Pb2+ were found to promote tannase activity, whilst 1.0 mmol L-1 of Ba2+, Ca2+, Mg2+, Zn2+, Hg+, Ag+, Co2+, Fe2+, Mn2+, Cu2+, Cd-2+, Al3+, K+, Ni2+, and Li+ inhibited tannase activity.