Fusion strategy enables high-level expression of fungal laccase in Pichia pastoris for efficient detoxification of aflatoxin B1 and zearalenone

作者：Lin Cui, Mengting Liu, Yang He, Ruiju Miao, Huiying Luo, Huoqing Huang, Xiaoyun Su, Jian Tian, Tao Tu, Yuan Wang, Xing Qin, Honglian Zhang, Jie Zhang, Yaru Wang, Bin Yao, Yingguo Bai, Xiaolu Wang · 发表于：Applied Food Research · 年份：2025 · DOI：10.1016/j.afres.2025.101475 · 被引用次数：3 · 研究领域：Mycotoxins in Agriculture and Food、Enzyme-mediated dye degradation、Fungal and yeast genetics research

• A fusion expression strategy was employed to express fungal laccase in P. pastoris. • The fusion protein can transform AFB 1 and ZEN without the need for mediators. • The transformed products showed significantly reduced toxicity. • The fusion protein has potential applications in detoxifying feed ingredients. Detoxification of aflatoxin B 1 (AFB 1 ) and zearalenone (ZEN), which pose substantial threats to both agriculture and food safety, using fungal laccases is an efficient and environmentally friendly technology. However, the difficulty in heterologous expression of fungal laccases has hindered their practical application. In this study, the expression of a Steccherinum ochraceum -originated laccase in Pichia pastoris X33 was achieved through fusion with an Aspergillus niger xylanase ( An XynB). The volumetric activity of laccase was enhanced from an undetectable level to 9102.0 U/L in a 15-L fermenter. Molecular docking of fusion proteins with mycotoxins indicated that So Lac potentially interacts with AFB 1 and ZEN directly. Optimized conditions were established for the mediator-free catalytic transformation of AFB 1 and ZEN using the An XynB- So Lac fusion protein, achieving transformation efficiencies of 71.0% and 72.9%, respectively, under 50 °C and pH 7.0 for 20 h. The main AFB 1 and ZEN transformation products were AFQ 1 , 13-OH-ZEN-quinone, 15-OH-ZEN, and ZOM-1, respectively. Evaluation of toxicity revealed that the transformed products exhibited markedly reduce...