Screening of high-yield tannase strain Aspergillus awamori FUYN206 and study of activity stability of its extracellular tannase

One fungal strain named Aspergillus awamori FUYN206, which could produce high yield of tannin acyl hydrolase, was isolated from Yunnan Black Tea.The activity of its extracellular tannase was 162.84U/mL when the strain grown at 30℃, pH5.0 under agitation (120r/min) for 72h.And the activity of extracellular tannase from Aspergillus awamori FUYN206 was reserved 98.02% and 90.49% after stored at 4℃ for four and twelve weeks respectively.The optimal reaction temperature was 40℃.Study on the stability of tannase activity that was shown the extracellular tannase had the superior stability of high-temperature.The activity of this tannase retained around 88% at 90℃ for 1h.The extracellular tannase was stable in the pH range of 3.0～6.5 and showed pH optima of 5.5.The activity of the extracellular tannase was enhanced by K+, Ag+, Zn2+.It was inhibited by Na+, Mg2+, Ca2+, Fe2+, Fe3+, Hg2+, Mn2+, Ba2+, particularly Co2+ and Cu2+.