漆酶具有染料脱色、织物表面改性和纺织品漂白的能力，因此在纺织工业中有着广泛的用途。筛选一种具有碱稳定性且适合纺织染料脱色应用的漆酶具有挑战性。该研究从黄瓜新杆菌（Neobacillus cucumis）中获得了一种新型碱性漆酶LacNC，并在大肠杆菌中进行了表达。LacNC是一种单体蛋白，其分子量大小为58 ku。LacNC以2,6-二甲氧基苯酚、丁香醛连氮（SGZ）和愈创木酚分别作为底物，其最适pH值分别为6.0、7.0和8.0。以愈创木酚为底物，LacNC最适温度为55 ℃。LacNC在pH值5.0~11.0范围内保持85%以上活性。在40 ℃孵育1 h后，保持80%以上活性。此外，LacNC对靛蓝胭脂红和孔雀石绿处理3 h，脱色率分别为90%和80%以上，对活性黑B的脱色率在24 h可达85%。综上所述，该研究获得了一种新型碱性漆酶，在碱性条件下对合成染料展现出较高的脱色效率，表明该漆酶是用于纺织工业废水处理的环保候选者。

Laccase is widely used in the textile industry for dye decolorization, fabric surface modification, and textile bleaching. Screening for a laccase that is alkaline stable and suitable for textile dye decolorization is challenging. A novel alkaline laccase (LacNC) was obtained from Neobacillus cucumis and expressed in Escherichia coli. LacNC is a monomeric protein with a molecular weight of 58 ku. The optimum pH values for LacNC were 6.0, 7.0, and 8.0 when 2,6-dimethoxyphenol, syringaldazine (SGZ), and guaiacol, respectively, were used as substrates. The optimal temperature for LacNC was 55 ℃ for the guaiacol substrate. The activity of LacNC remained more than 85% in the pH range of 5.0~11.0. After incubation at 40 ℃ for 1 h, the activity of LacNC was still higher than 80%. In addition, the decolorization rates of indigo carmine and malachite green by LacNC were more than 90% and 80% in 3 h, respectively, and the decolorization rate of reactive black B by LacNC reached 85% in 24 h. In this study, a new alkaline laccase demonstrating high decolorization efficiency for synthetic dyes under alkaline conditions was obtained. Hence, this laccase is an environmentally friendly candidate for treating wastewater in the textile industry.

国家重点研发计划项目（2021YFC2104001）