Partial purification and characterization of Aspergillus tamarii IMI388810 (B) tannin acyl hydrolase

By Simeon Chukwuemeka Enemuor and Fredrick John Chidi Odibo 

ABSTRACT

Aspergillus tamarii IMI388810 (B) a tannic acid degrading fungus produced two major tannases in a fermentation medium M, containing tannic acid as the only carbon source.  The culture broth was filtered through filter paper and the crude enzyme filtrate was concentrated by dialysis against different changes of 6M sucrose solution. The tannases were separated by Ion-exchange chromatography on Q-Sepharose Fast Flow column and Phenyl Sepharose 6 Fast Flow (High Sub) hydrophobic interaction chromatography and were identified as Tannase I and II. The optimum temperature for enzyme activity was 35oC for Tannase I and 50oC for Tannase II. Both tannases retained over 70% of its activity between 35o and 50oC, for 30 minutes. The optimum pH for the enzyme activity was 5.0 for Tannase I and 3.0 for Tannase II and with their maximum stability at pH 3.0 and 6.0, respectively. Their Km values for methyl gallate were 0.08 mM, for Tannase I, and 0.02mM, for Tannase II. Ca2+, Co2+, Cu2+, Fe2+, Hg2+, Mg2+, Mn2+, SDS, EDTA, EGTA and Bromosuccinamide were inhibitory to the Tannases.   

Keywords: Aspergillus tamarii IMI388810 (B), tannin acyl hydrolase, partial purification and characterization.

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