重组里氏木霉产漆酶及其对染料金橙Ⅱ的脱色

Laccase production by recombinant Trichoderma reesei and its application for decolorization of gold orangeⅡ

对已有的10个重组里氏木霉转化子进行产酶试验,从中筛选到一个高产转化子,摇瓶发酵96h,漆酶活力可以达到8.85IU/mL.SDS-PAGE结果表明：该重组漆酶的相对分子质量约为68 000.重组漆酶的最适温度为65℃,该酶具有较好的耐热性能,经70℃处理60min后残余相对酶活维持在70%以上;最适pH为2.2,在pH为2.6-4.2的条件下具有良好的稳定性.采用发酵粗酶液对100mg/L的偶氮染料金橙Ⅱ进行脱色试验,对影响脱色效果的主要因子进行研究.结果表明,在温度为50℃、pH为3.5、介体HOBT用量为2mmol/L、漆酶用量为0.2IU/mL的条件下作用5h,金橙Ⅱ的脱色率可以达到90.6%.

A transformant of 10 recombinanttransformants Trichoderma reesei with high by fermentation experiment, and production of laccase was screened from the maximum laccase activity was achieved at 96 h （8.85 IU · mL^-1） in shaking flask. SDS-PAGE analysis showed that the recombinant laccase had a relative molecular mass of around 68 000. The optimum temperature and;pH value for the recombinant laccase reaction were 65 ℃ and 2.2, respectively. The laccase was stable at pH between 2.6 and 4.2. Approximately 70% of the initial enzyme activity was retained after incubation of the laccase at 70 ℃ for 60 min, indicating that the laccase was highly thermostable. The effects of primary factors on the decolorization of gold orange Ⅱ （100 mg. L-1）were analyzed and the decolorization rate reached 90.6% in 5 h at 50 ℃, pH 3.5, HOBT concentration 2 mmol · L^-1 and laccase dosage 0.2 IU· mL^-1. Excellent thermostability and efficient decolorization suggest that this crude recombinant laccase can be effectively applied to decolorize the recalcitrant azo dyes from effluents.