Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Wuxi 214122, China.
Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.
Bioresour Technol. 2015 Feb;177:387-92. doi: 10.1016/j.biortech.2014.11.055. Epub 2014 Nov 20.
In our previous work, a recombinant Bacillus subtilis strain for the microbial production of N-acetylglucosamine (GlcNAc) was constructed through modular pathway engineering. In this study, to enhance GlcNAc production, glucose feeding approaches and dissolved oxygen (DO) control methods in fed-batch culture were systematically investigated. We first studied the effects of different glucose feeding strategies, including exponential fed-batch culture, pulse fed-batch culture, constant rate fed-batch culture, and glucose control (5 g/L, 10 g/L, 15 g/L) fed-batch culture, on cell growth and GlcNAc synthesis. We found that GlcNAc production in glucose control (5 g/L) fed-batch culture reached 26.58 g/L, which was 3.10 times that in batch culture. Next, the effect of DO level (20%, 30%, 40%, and 50%) on GlcNAc production was investigated, and a step-wise DO control strategy (0-7 h, 30%; 7-15 h, 50%; 15-50 h, 40%; 50-72 h, 30%) was introduced. With the optimal glucose and DO control strategy, GlcNAc production reached 35.77 g/L, which was 4.17 times the production in batch culture without DO control.
在我们之前的工作中，通过模块化途径工程构建了用于微生物生产 N-乙酰氨基葡萄糖（GlcNAc）的重组枯草芽孢杆菌菌株。在这项研究中，为了提高 GlcNAc 的产量，系统研究了分批补料培养中的葡萄糖补料方法和溶解氧（DO）控制方法。我们首先研究了不同的葡萄糖补料策略对细胞生长和 GlcNAc 合成的影响，包括指数补料分批培养、脉冲补料分批培养、恒速补料分批培养和葡萄糖控制（5 g/L、10 g/L、15 g/L）补料分批培养。我们发现，葡萄糖控制（5 g/L）补料分批培养中的 GlcNAc 产量达到 26.58 g/L，是分批培养的 3.10 倍。接下来，研究了 DO 水平（20%、30%、40%和 50%）对 GlcNAc 产量的影响，并引入了逐步 DO 控制策略（0-7 h，30%；7-15 h，50%；15-50 h，40%；50-72 h，30%）。采用最佳的葡萄糖和 DO 控制策略，GlcNAc 产量达到 35.77 g/L，是没有 DO 控制的分批培养产量的 4.17 倍。
