Qu Jinghua, Long Jie, Li Xingfei, Zhou Xing, Chen Long, Qiu Chao, Jin Zhengyu
The State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Foods. 2024 Oct 19;13(20):3324. doi: 10.3390/foods13203324.
The demand for food-grade β-mannanases, ideal for high-temperature baking, is increasing. Using the () expression system for β-mannanase production, this study aimed to enhance purification methods. We evaluated better conditions for production and purification of β-mannanase (Man134A) from recombinant X-33, focusing on a higher purity and reducing the production of endogenous secretory proteins in fermentation. By adjusting carbon and nitrogen sources, culture time, and temperature, we controlled cell growth to reduce the production of endogenous secretory proteins. The better-evaluated conditions involved culturing recombinant in 70 mL buffered glycerol complex medium for 24 h at 30 °C, then in modified buffered methanol-complex medium with 0.91% (/) methanol, 0.56% (/) sorbitol, and 0.48% (/) mannitol for another 24 h, which improved the Man134A yield and reduced endogenous secretory proteins, shortening the fermentation time by 72 h. An affordable purification method using ultrafiltration and salt-out precipitation was utilized. Man134A showed thermostability up to 100 °C and effectively degraded locust bean gum into smaller fragments, mainly producing mannotriose. In conclusion, with its enhanced purity due to reduced levels of endogenous secretory proteins, purified Man134A emerges as a promising enzyme for high-temperature baking applications.
对适用于高温烘焙的食品级β-甘露聚糖酶的需求正在增加。本研究利用()表达系统生产β-甘露聚糖酶,旨在改进纯化方法。我们评估了从重组X-33生产和纯化β-甘露聚糖酶(Man134A)的更佳条件,重点是提高纯度并减少发酵过程中内源性分泌蛋白的产生。通过调整碳源和氮源、培养时间和温度,我们控制细胞生长以减少内源性分泌蛋白的产生。评估出的更佳条件包括在70 mL缓冲甘油复合培养基中于30°C培养重组菌24 h,然后在含有0.91%(/)甲醇、0.56%(/)山梨醇和0.48%(/)甘露醇的改良缓冲甲醇复合培养基中再培养24 h,这提高了Man134A的产量并减少了内源性分泌蛋白,使发酵时间缩短了72 h。采用了一种使用超滤和盐析沉淀的经济实惠的纯化方法。Man134A在高达100°C时表现出热稳定性,并能有效地将刺槐豆胶降解为更小的片段,主要产生甘露三糖。总之,由于内源性分泌蛋白水平降低,纯化后的Man134A纯度提高,成为高温烘焙应用中一种有前景的酶。