Production and Partial Enzymatic Characteristics of Pectinase from Apple Pomace by Aspergillus niger HG-1 in Solid State Fermentation

Objective:Optimize the culture medium and fermentation conditions of Aspergillus niger HG-1 to produce pectinase from apple pomace in solid state fermentation;and reveal some prime characteristic of the pectinase.Method:Monofactorial and orthogonal experiments were adopted in solid state fermentation.Result:The activity of pectinase reached 22 248U/g when Aspergillus niger HG-1 was cultured at 30℃ for 48h in the optimized medium containing 10g apple pomace,10g cottonseed meal,0.2g(NH4)2SO4 and 0.06g KH2PO4 at the optimized conditions including moisture content of solid substrate 60%(w/w) and 20g dry substrate /250ml flask.The optimal temperature and pH of pectinase reaction were at 45℃ and pH 5.0.Pectinase was stable below 50℃ and between pH 3.0 and pH 6.0.Ca2+,Mg2+ and Fe2+ increased pectinase activity whereas Ba2+,Mn2+,Zn2+ obviously inhibited it.Conclusion:It was technically and economically feasible to produce pectinase from apple pomace by Aspergillus niger HG-1 in solid state fermentation.It was also an effective way to make the best of apple pomace,an agricultural waste produced in larger quantities in China.