烟曲霉产壳聚糖酶液体发酵条件研究

Study on conditions of chitosanase from Aspergillus fumigatus by liquid fermentation

以烟曲霉(Aspergillus fumigatus)为出发菌,通过选择适合的培养条件,筛选出产壳聚糖酶的菌株。实验结果表明,烟曲霉是良好的产壳聚糖酶出发菌。烟曲霉液体发酵产壳聚糖酶最适培养基组成为:壳聚糖1%,KH2PO40.06%,尿素0.2%,(NH4)2SO40.1%,MgSO40.012%,20%土豆汁3%,NaCl 0.05%。在pH 5.0、温度28℃、摇床转速120 r/min培养条件下振荡培养3 d,烟曲霉产壳聚糖酶的能力最强,达25.1 U/mL。

A mutant of Aspergillus fumigatus, which could synthesize chitosanase effectively under the optimized conditions, was obtained with selective nutrient mediums. The optimized liquid fermentation mediums were as follows： chitosan 1%,KH2PO40.06%, Urea 0.2%,（NH4）2SO40. 1%,MgSO40. 012%, 20%potato juice 3%,NaCl0.05%, and pH5.0. After 3 days＇ fermentation at 120 r/min and 28℃, the chitosanase activity produced by the mutant of A. fumigatus reached a higher level of 25.1 U/mL.