Zhang Long-Bin, Deng Zhi-Qiang, Qiu Ting-Ting, Yang Wu-Wei-Jie, Zhu Fan, Ye Xiu-Yun
Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian, 350116, China.
Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian, 350116, China.
Fungal Biol. 2023 Jan-Feb;127(1-2):872-880. doi: 10.1016/j.funbio.2022.11.005. Epub 2022 Dec 2.
Phenolic compounds are widely distributed in nature and industrial environment, and their detoxification or bioactive enhancement is of great value to environmental protection and industrial development. Laccases are multicopper oxidases that catalyse the oligo- or polymerisation of phenolic compounds. Identifying new laccase producers and investigating their application potential are of great importance. In this study, a white-rot fungus, Trametes hirsuta EZ1, with significantly high laccase productivity was isolated. The optimum conditions were studied for the maximum fermentation of extracellular laccase, which was achieved at 150 U/mL with a medium containing 10% strain EZ1, 7% maltodextrin, 1.5% peptone, and 0.5 mM Cu, and incubation at initial pH 6.0, 32 °C, and 180 rpm for nine days. Subsequently, a 70-kDa laccase was purified that showed activity over a wide range of temperature and pH, sensitivity to many metal ions and sodium dodecyl sulphate, and high tolerance to organic solvents. Purified laccase showed a significant unreported effect by catalysing catechol or ferulic acid into dimers, trimers, and tetramers or caffeic acid into dimers, trimers, tetramers, and pentamers. The oligomeric mixtures exhibited increased antioxidative capacity compared to that of each parent monomer, except for caffeic acid derivatives. Our study offers a novel strain source for laccase production and broadens its application in the enhancement of bioactive compounds.
酚类化合物广泛分布于自然和工业环境中，其解毒或生物活性增强对环境保护和工业发展具有重要价值。漆酶是一类多铜氧化酶，可催化酚类化合物的寡聚或聚合反应。鉴定新的漆酶产生菌并研究其应用潜力具有重要意义。在本研究中，分离出了一株漆酶产量显著较高的白腐真菌——粗毛栓菌EZ1。研究了胞外漆酶最大发酵的最佳条件，在含有10%菌株EZ1、7%麦芽糊精、1.5%蛋白胨和0.5 mM铜的培养基中，初始pH值为6.0、32℃、180 rpm条件下培养9天，漆酶产量可达150 U/mL。随后，纯化得到了一种70 kDa的漆酶，该漆酶在较宽的温度和pH范围内均表现出活性，对多种金属离子和十二烷基硫酸钠敏感，对有机溶剂具有较高的耐受性。纯化后的漆酶通过催化儿茶酚或阿魏酸形成二聚体、三聚体和四聚体，或催化咖啡酸形成二聚体、三聚体、四聚体和五聚体，表现出显著的未报道的作用。除咖啡酸衍生物外，与各亲本单体相比，寡聚混合物的抗氧化能力有所增强。我们的研究为漆酶生产提供了一种新的菌株来源，并拓宽了其在生物活性化合物增强方面的应用。
