Enhancement of Sulfur Conversion Rate in the Production of L-Cysteine by Engineered Escherichia coli
Enhancement of Sulfur Conversion Rate in the Production of L-Cysteine by Engineered Escherichia coli
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DOI：
10.1021/acs.jafc.9b06330
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发表时间：
2020-01-08
影响因子：
6.1
通讯作者：
Li, Zhimin
中科院分区：
文献类型：
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作者：
Liu, Han;Hou, Yehua;Li, Zhimin
半胱氨酸是一种重要的含硫氨基酸，广泛用于农业和食品工业。在以发酵为基础的半胱氨酸生产中，实现高硫转化率是非常可取的。本研究对大肠杆菌进行代谢工程，以提高半胱氨酸生物合成中硫的转化率。因此，减少硫损失的调节器decR及其yhaOM操作子被删除。serACB通过组成启动子整合到染色体上，协调提高硫的利用。硫同化途径和硫转录调节因子cysB过表达，显著调节硫代谢，促进硫转化。经补料分批发酵工艺优化后，LH16 [SLH02 Delta yhaM Ptrc1-serACB-cysM-nrdH-(pLH03, pTrc99a-cysB)]产半胱氨酸7.5 g/L，硫转化率为90.11%。这些结果表明，LH16在农业和食品工业中生产半胱氨酸是一个有价值的过程。
Cysteine is a commercially important sulfur-containing amino acid widely used as a supplement in the agricultural and food industries. It is extremely desirable to achieve a high sulfur conversion rate in the fermentation-based cysteine production. Here, the metabolic engineering of Escherichia coli was performed to enhance the sulfur conversion rate in cysteine biosynthesis. Accordingly, the reduction of sulfur loss by the regulator decR and its yhaOM operons were deleted. serACB was integrated into chromosome with constitutive promoter to coordinately increase sulfur utilization. The sulfur assimilation pathways and sulfur transcriptional regulator cysB were overexpressed to regulate sulfur metabolism and enhance sulfur conversion significantly. After the process optimization in fed-batch fermentation, LH16 [SLH02 Delta yhaM Ptrc1-serACB-cysM-nrdH-(pLH03, pTrc99a-cysB)] produced 7.5 g/L of cysteine with a sulfur conversion rate of 90.11%. These results indicate that cysteine production by LH16 is a valuable process in the agricultural and food industries.