染料的香菇漆酶脱色研究

Decolorization of dyes catalyzed by laccase from dried mushrooms

利用来源于香菇的粗漆酶与20种工业染料反应，结果发现其中13种染料的颜色能被脱除。研究了影响偶氮类染料媒介元PV和葸醌类染料依利尼尔蓝A-R的漆酶脱色的相关因素，试验发现，这两种染料在1h内与漆酶反应迅速，且特征颜色吸收峰（531nm／628nm）基本消失，其最适温度均为60℃；最适反应pH值范围分别为4～5和5～6；最佳染料浓度范围分别为0．06～0．08g／L和0．04～0．08g／L；酶活力的增加可以显著提高反应速率，但对总脱色率影响不大；在pH值为5、温度40℃条件下，0．66U／mL的漆酶与媒介元PV和依利尼尔蓝A-R反应的Km值分别为（186±16）μM和（268±63）μM，Vmax值分别为（72．6±22）μM／min和（25．7±7）μM／min。

Crude laccase from a white-rot fungus Lentinula edodes was used to react with 20 commercial dyes. The results showed that 13 dyes＇ color were removed more or less. Relevant factors that affected the decolorization of two synthetic dyes （Diamond Black PV and Erionyl Blue A-R） were studied. These two dyes were discolored rapidly within 1h, and the characteristic peaks of them at λmax 531/628 nm disappeared basically. The optimum temperature was 60 ℃ for both of them. The optimum pH range for the decolorization was 4～5 for Diamond Black PV and 5～6 for Erionyl Blue A-R respectively. The optimum concentration range of dyes was 0.06～0.08 g/L for the former and 0.04～0.08 g/L for the latter. Increasing enzyme activity could improve the decolorization velocity, but did not affect a lot on the total decolorization ratio. Determination of Km, and Vmax value of the Diamond Black PV and the Erionyl Blue A-R were carried out with 0.66 U/mL laccase at pH value 5 and 40℃. The Km value was about （186±16） μM and （268±63） μM, respectively, which means the affinity of Diamond Black PV with laccase is higher than that of the Erionyl Blue A-R. The Vmax was （72.6±22） and （25.7±7） μM/min, respectively, which means the Diamond Black PV is catalysed more easily than the Erionyl Blue A-R.