白地霉产漆酶条件优化及对偶氮染料的脱色

Optimization of Laccase Production from Geotrichum candidum and Decoloration of Azo Dyes by Laccase

从印染废水中筛选出一株产漆酶的真菌,经鉴定为白地霉(Geotrichum candi-dum).对该白地霉M3产漆酶的条件和所得漆酶对偶氮染料的脱色能力进行研究.结果表明:葡萄糖、氯化铵为白地霉M3产漆酶的最佳碳源和氮源,产漆酶优化培养基包含2g/L的葡萄糖、1.5g/L的氯化铵、0.015 mmol/L的愈创木酚和0.05 mmol/L的硫酸铜.使用5 L机械搅拌式发酵罐和7L气升式发酵罐在优化培养基条件下培养白地霉M3,最高漆酶酶活分别达到23.8和36.9μmol/(s.L),气升式发酵罐更适合白地霉M3产漆酶.获取的粗漆酶液处理偶氮染料1.5h后,脱色率达到90.2%;可见-紫外光谱扫描分析表明白地霉M3所产漆酶能降解偶氮染料.

A fungus producing laccase was screened from dyeing wastewater and was identified as Geotrichum candidum （ G. candidum） M3. Then, the production conditions of laccase from G. candidum M3 and the decoloration ability of laccase for azo dyes were investigated. The results show that （ 1 ） glucose and ammonium chloride are respectively the best carbon and nitrogen sources for the production of laccase from G. candidum M3 ; （2） the optimal contents of glucose, ammonium chloride, guaiacol and copper sulfate for culturing laccase are respectively 2 g/L, 1.5 g/L, 0. 015 mmol/L and 0. 05 mmol/L; （ 3 ） the highest activities of laccase produced from G. candidum M3 under optimal conditions in a 5-L mechanically-stirred fermentor and a 7-L air-lift fermentor reach 23.8 and 36. 9μmol/（s· L）, respectively; （4） the air-lift fermentor is more suitable for the laccase production from G. candidum M3 ; and （5） after a treatment with the produced crude laccase for 1.5 h, the decoloration rate of azo dyes reaches 90. 2%. The decoloration ability of the produced laccase for azo dyes is also proved by Vis-UV spectrum.