Abstract A codon-optimised β-mannanase gene from Aspergillus niger (AnMan26) was heterologously expressed in Pichia pastoris. The peak enzyme activity of 22,100 U mL−1 was achieved in a 5-L fermenter. AnMan26 was purified to homogeneity with 1.6-fold purification via Sephacryl S100 HR gel filtration. It exhibited optimal activity at pH 5.0 and 45 °C. AnMan26 was stable within the pH range 2.5–7.0 and exhibited good thermostability up to 40 °C. Moreover, it revealed highest specific activity of 2869.0 U mg−1 towards locust bean gum, and efficiently degraded various mannans to manno-oligosaccharides and hydrolysed mannotetraose and mannopentaose. Furthermore, AnMan26 hydrolysed fenugreek gum to yield partially hydrolysed fenugreek gum (PHFG) with the weight-average molecular weight of 1.8 × 103 Da. The hydrolysis ratio of galactomannan in fenugreek gum was 82.2 %. Thus, an effective β-mannanase for PHFG production was produced in this study.

中文翻译：

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毕赤酵母中黑曲霉糖苷水解酶家族 26 β-甘露聚糖酶的高水平表达，用于生产部分水解的葫芦巴胶

摘要 来自黑曲霉的密码子优化的 β-甘露聚糖酶基因 (AnMan26) 在毕赤酵母中异源表达。在 5 L 发酵罐中达到了 22,100 U mL-1 的峰值酶活性。AnMan26 通过Sephacryl S100 HR 凝胶过滤以1.6 倍纯化纯化至均质。它在 pH 5.0 和 45 °C 下表现出最佳活性。AnMan26 在 pH 值范围 2.5-7.0 内是稳定的，并且在高达 40°C 时表现出良好的热稳定性。此外，它对刺槐豆胶的最高比活性为 2869.0 U mg-1，并能有效地将各种甘露聚糖降解为甘露寡糖和水解甘露四糖和甘露五糖。此外，AnMan26 水解葫芦巴胶，得到重均分子量为 1.8 × 103 Da 的部分水解葫芦巴胶 (PHFG)。葫芦巴胶中半乳甘露聚糖的水解率为82.2%。因此，在本研究中产生了用于 PHFG 生产的有效 β-甘露聚糖酶。