一株人体条件致病菌烟曲霉液体培养所产果胶酶的酶学性质

Enzymatic Characterization of Pectinase Produced Using Liquid Cultivation of a Human Opportunistic Pathogenic Fungi Aspergillus fumigatus Strain

本研究从土壤样品中分离得到一株能在桔子皮粉基质中生长的真菌XYYWZSP2,后续通过分析其基因组内转录间隔区基因序列将其鉴定为烟曲霉。该菌株在液态培养中产果胶酶(2.01±0.02)U·mL^(-1)。该果胶酶的最适作用pH值为4.5,并且在pH值4.5~9.0比较稳定。该果胶酶在40℃下比较稳定,在50℃保温1 h后剩余约1/2酶活力。该果胶酶在实验室香蕉果汁的生产中表现很好,在50℃保温12 h后,可使果汁的产量增加25.78%±2.21%,使果汁中还原性物质的量增加20.22%±1.50%。

In this study,a fungal strain XYYWZSP2 was isolated on medium plate containing orange peel,and it was subsequently identified as Aspergillus fumigatus by analysis of internal transcribed spacer sequence.It produced pectinase in liquid cultivation of(2.01±0.02)U·mL^(-1).The produced pectinase showed optimal pH of 4.5 and relative stable in a wide pH range of 4.5~9.0.The produced pectinase was stable at 40℃and retained about half enzyme activity after one hour incubation at 50℃.The enzyme was applied in lab scale banana juice production and showed an excellent performance.After 12 hours incubation at 50℃,the pectinase increased the yield of juice by 25.78%±2.21%and reducing material by 20.22%±1.50%.