产果胶酶曲霉菌株的筛选、果胶酶酶学性质及在香蕉果汁生产中的应用

Screening of pectinase producing Aspergillus strain,enzymatic properties of pectinase and its application in banana juice production

本研究从土壤中分离筛选得到一株产果胶酶的丝状真菌XYYWZSP4,用以橘子皮粉为碳源的液体培养基培养5 d后,培养液中的果胶酶活力为0.78±0.01 U/mL。观察该菌株在察氏培养基平板上的形态和分生孢子梗的形态,鉴定其为曲霉。测得该菌株液体培养产生果胶酶的酶学性质:最适作用pH值为4.5,最适作用温度为60℃,在pH值3.0~8.0范围内稳定(残余酶活力高于90%),在不高于40℃环境下稳定。该果胶酶具有优良的金属离子相容性,在所有供试金属离子中,仅5 mM钙离子抑制该酶的酶活力。将该果胶酶应用于实验室试验香蕉果汁生产中,得到果汁产率达(89.85±1.57)%,果汁中还原性物质含量达(11.53±0.09) g/L。

A filamentous fugal strain XYYWZSP4 producing pectinase was isolated from soil sample,and(0.78±0.01)U/mL of pectinase activity in culture broth was produced by using orange peel powder as sole carbon source.It was identified as Aspergillus sp.by observation of colony characters on Czapek medium plate and conidiophore.The enzyme property of its pectinase was determined as following:optimal pH at 4.5,optimal temperature at 60℃,stable at pH range of 3.0-8.0(with residual enzyme activity higher than 90%);stable at temperature not higher than 40℃.The pectinase had excellent metal ions compatibility with only inhibition effect of calcium at 5 mM among all tested metal ions.When the pectinase was applied in banana juice production,the juice yield of(89.85±1.57)%and reducing material concentration of(11.53±0.09)g/L were obtained.