刺芹侧耳产漆酶条件优化及对偶氮染料甲基橙的脱色

漆酶是一种含铜的单电子多酚氧化酶,能够催化氧化各种酚类及多种染料,在处理染料废水方面具有巨大的潜力。刺芹侧耳Pleurotus eryngii具有较强的产漆酶能力,但漆酶产量在较大程度上受环境条件限制。本文研究了氮源含量、pH、温度、金属离子等环境条件对刺芹侧耳产漆酶能力的影响,优化了其产漆酶条件,并用其粗酶液对典型偶氮类染料甲基橙进行脱色,结果表明,在氮源0.5%（W/W）、pH 5.5、温度28℃、添加5.0mmol/L Mg ²⁺的培养条件下,刺芹侧耳产漆酶能力最强,培养6d时,漆酶酶活可达78.0U/L。用优化培养的刺芹侧耳粗酶液对偶氮染料甲基橙进行脱色,28h后脱色率可达90%,脱色反应为准一级动力学反应,甲基橙并未完全矿化,而是生成小分子中间产物。

Optimization of conditions for laccase production by Pleurotus eryngii and application of laccase to azo dye methyl orange decolorization

Laccase is a copper-containing single-electron polyphenol oxidase, which can catalyze oxidation of various phenols and dyes, and has great potential in the treatment of dye wastewater. Pleurotus eryngii has a strong ability to produce laccase, but laccase production is restricted by environmental conditions to a large extent. In this study, the culture conditions of P. eryngii for increasing laccase production were optimized and the ability of the crude enzyme to decolorize azo dye methyl orange solution was also observed. The results showed that the laccase production capacity of P. eryngii was strongly increased upon condition that the mass proportion of nitrogen source was 0.5%, pH value 5.5, cultural temperature 28°C and 5.0mmol/L Mg ²⁺ was added. Under such an optimized condition, the laccase activity reached 78.0U/L in 6 days. In 28h, the decolorization rate of azo dye methyl orange by the crude enzyme reached 90%. The result indicated that the decolorization reaction was a pseudo-first-order kinetic reaction. The dye was not fully mineralized, but generated small molecular intermediates.