Biosynthesis of gallic acid and tannase from Dacryodes edulis (African Pear) seeds using Aspergillus niger SCSGAF0145 by submerged fermentation

Aspergillus niger SCSGAF0145 previously isolated and identified by our group as a tannase producer from soil was grown under submerged fermentation using pear seed as source of tannic acid. Crude tannase was precipitated out of the cell free broth and purified by gel filtration gave a purified enzyme with specific activity of 6.65 U/mg, with a final yield and purification fold of 42.08% and 5.94 respectively. The deduced Vmax of the purified tannase was 17.57 U/mL and Km was 1.59 mg/mL. The optimal temperature and pH of the enzyme using tannic acid as sole carbon source was 40 °C and 5.5 respectively. Conclusively, pear seed is a good substrate for gallic acid and tannase production by Aspergillus niger SCSGAF0145 and tannase secreted can be explored in various industrial processes.