微酸多年卧孔菌产漆酶条件优化及其在染料脱色中的应用

Optimization of Conditions for Laccase Production by Perenniporia subacida and Its Application in Dye Decolorization

微酸多年卧孔菌(Perenniporia subacida)产漆酶能力对生物漂白等研究具有重要意义.通过单因子和正交试验确定了微酸多年卧孔菌(菌株号:Dai 8224)的最适产酶条件:麦芽糖20 g/L,酵母浸粉5 g/L,pH 5.4,Cu2+2.0 mmol/L,培养温度24℃,转速160 r/min,接种量1.5%(V/V),此时酶活最高可达1.945 U/mL.单独使用微酸多年卧孔菌漆酶粗酶液对染料具有很好的脱色效果.该菌株对于50 mg/L杂环类染料中性红的脱色率可达98.3%,对偶氮染料刚果红的脱色率次之,为91.57%,对亚甲基蓝和铬天青的脱色率也都在80%以上.此外,其催化中性红脱色的最佳底物浓度为60 mg/L,脱色率达到99.42%,其中,生物降解作用占55.92%,菌体吸附作用占43.5%.结果表明该菌对多种染料脱色具有较大的应用潜力.

It will be of great significance that the laccase productivity of Perenniporia subacida,a species of white-rot fungi,is explored for bio-blanching.In this study,the optimal culture conditions of strain Dai 8224 for laccase production were obtained by means of single factor analysis and orthogonal test： Maltose 20 g/L,yeast extract 5 g/L,pH 5.4,Cu2＋ 2.0 mmol/L,culture temperature 24 ℃,shaking speed 160 r/min,and inoculum 1.5%（V/V）,which contributed to the highest enzyme activity as 1.945 U/mL.The crude laccase from P.subacida had the ability to decolor several kinds of dyes including neutral red,congo red,methylene blue and chromazurine.Correspondingly,the decolorization rate was up to 98.3% and 91.57% for neutral red and congo red,respectively,and more than 80% for methylene blue and chromazurine.Furthermore,the optimal concentration of the substrate for decolorizing neutral red was 60 mg/L and the decolorization rate was up to 99.42%,of which 55.91% was biodegraded by laccase and 43.51% was adsorbed by the mycelia.The results indicated that P.subacida（strain Dai 8224） had a great prospect in the treatment of dye-containing wastewater.Fig 4,Tab 3,Ref 31