锰过氧化物酶(MnP)是白腐菌分泌的一种能有效降解木质素及多种异生物质的过氧化物酶。首先对一色齿毛菌在初始条件下进行培养,获得其产生MnP的活性规律曲线,进而进行最佳碳源和最佳氮源的筛选及2次正交试验对一色齿毛菌产MnP的培养条件进行优化;然后对优化后的胞外酶液进行5种染料的脱色研究。结果表明,一色齿毛菌产MnP的最优组合为:果糖10 g·L^-1、硝酸铵0.2 g·L^-1、Mn2+2.67 mmol·L^-1、pH 5.5、250 mL三角瓶70 mL装液量、150 r·min^-1摇瓶培养、接种=8 mm的菌片9片、在34℃下培养7天后MnP活性高达95.47 U·L^-1,是初始培养条件最高酶活的5.2倍。染料脱色结果表明,一色齿毛菌对3种结构类型的5种染料都有较大程度的脱色,其中8天时对活性黑的脱色最为彻底,脱色率为98.4%;对中性红、结晶紫、活性红和刚果红的脱色率也高达72.3%-89.4%。
Manganese peroxidase (MnP) is secreted by white-rot fungi, it can degrade lignin and various xenobiotics efficiently. Cerrena unicolor was firstly cultured under initial conditions and the curve of its MnP activity was gained. Then, 5 kinds of carbon sources and 5 kinds of nitrogen sources were selected, and two orthogonal tests were conducted to optimize medium compositions and culture conditions of C. unicolor producing MnP. Optimized extracellular MnP solutions were determined to decolour 5 kinds of dyes. Results showed that the most optimal culture parameters for MnP production was fructose 10 g·L-1 , ammonium nitrate 0. 2 g·L-1 , Mn2+2. 67 mmol·L-1 ,pH 5.5, 70 mL culture solution in 250 mL flask at 150 rmin-1 shaking condition, 9 tablets of 0 = 8 mm inocula, and temperature 34 ℃. The highest MnP activity reached 95.47 U·L-1 after 7 d culture, which was 5.2 times than that produced at initial conditions. Decolorization test showed that optimized extracellular MnP solutions of C. unicolor had effectively decoloring ability to 5 kinds of dyes belonging to 3 kinds of group. The decolorization rate of the 5 kinds of dye all reached maximum after 8 d. On 8 days of incubation, reactive black was almost completely decolorized, the decolorization percent was as high as 98.4%, and at that time the decolorization percents to congo redr, reactive red, crystal violet, and neutral red were also as high as 72. 3% - 89. 4%.