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Development of a fermentation strategy to enhance the catalytic efficiency of recombinant Escherichia coli for l-2-aminobutyric acid production
3 Biotech ( IF 2.8 ) Pub Date : 2021-07-28 , DOI: 10.1007/s13205-021-02937-y
Jian-Miao Xu 1, 2, 3 , Ming Wang 1, 2, 3 , Yi-Hua Jin 1, 2, 3 , Zhi-Qiang Liu 1, 2, 3 , Yu-Guo Zheng 1, 2, 3
Affiliation  

Microbial fermentation for enzyme production and then whole-cell catalysis for l-2-aminobutyric acid (l-ABA) production have huge potential for industrial application, but the catalytic capacities of cells are directly related to the fermentation process. Using a 50 L fermenter, the effects of initial glycerol concentration in the medium and rotating speed on cell catalytic capacity were investigated. Fermentation cells showed the best catalytic activity when the initial glycerol concentration was 12 g/L and the rotating speed was 250 rpm. Furthermore, we studied the difference between glycerol and glycerol mixtures as fed-batch media in pH–stat fed-batch fermentation. Results showed that glycerol had better catalytic activity than the glycerol mixture, and the effect of fed-batch fermentation was better than batch fermentation. Meanwhile, the enzyme activities of leucine dehydrogenase and formate dehydrogenase reached 129.87 U/g DCW and 437.02 U/g DCW, respectively, and the intracellular NAD(H) concentration reached 14.94 μmol/g DCW. Using the optimized fermentation parameters, amplified fermentation was then carried out in a 5000 L fermenter to demonstrate the industrial production of l-ABA by Escherichia coli BL21.



中文翻译:

开发一种发酵策略以提高重组大肠杆菌对 l-2-氨基丁酸生产的催化效率

微生物发酵生产酶,然后全细胞催化生产l -2-氨基丁酸 ( l-ABA)生产具有巨大的工业应用潜力,但细胞的催化能力与发酵过程直接相关。使用 50 L 发酵罐,研究了培养基中初始甘油浓度和转速对细胞催化能力的影响。当初始甘油浓度为12 g/L、转速为250 rpm时,发酵细胞的催化活性最好。此外,我们研究了甘油和甘油混合物在 pH-stat 补料分批发酵中作为分批补料培养基的差异。结果表明,甘油比甘油混合物具有更好的催化活性,分批补料发酵的效果优于分批发酵。同时,亮氨酸脱氢酶和甲酸脱氢酶的酶活性分别达到129.87 U/g DCW和437。02 U/g DCW,细胞内NAD(H)浓度达到14.94 μmol/g DCW。使用优化后的发酵参数,在5000 L发酵罐中进行放大发酵,以证明其工业化生产。l -ABA来自大肠杆菌BL21。

更新日期:2021-07-28
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