Coordinated Expression of Astaxanthin Biosynthesis Genes for Improved Astaxanthin Production in Escherichia coli
Coordinated Expression of Astaxanthin Biosynthesis Genes for Improved Astaxanthin Production in Escherichia coli
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虾青素生物合成基因的协调表达以提高大肠杆菌中虾青素的产量
DOI：
10.1021/acs.jafc.0c05379
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发表时间：
2020-12-16
影响因子：
6.1
通讯作者：
Zhang, Xueli
中科院分区：
文献类型：
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作者：
Gong, Zhongkuo;Wang, Honglei;Zhang, Xueli
虾青素具有很强的抗氧化能力，在饲料、化妆品、保健品等行业具有巨大的潜在商业价值。本研究选择代谢流完全平衡的大肠杆菌菌株CAR 026作为出发菌株进行虾青素的生产。协调催化β-胡萝卜素转化为虾青素的β-胡萝卜素酮醇酶（CrtW）和β-胡萝卜素羟化酶（CrtZ）的表达，通过增加CAR 026中crtY的拷贝数消除了一个瓶颈。所得菌株Ast 007在摇瓶中产生21.36mg/L和4.6mg/g DCW的虾青素。此外，通过调控分子伴侣基因groES-groEL，进一步提高了虾青素产量。最佳菌株Gro-46在流加发酵条件下发酵60 h后，摇瓶产率为6.17 mg/g DCW，产率为26 mg/L，1.18 g/L。据我们所知，这是使用工程化E.到目前为止。
Astaxanthin has great potential commercial value in the feed, cosmetics, and nutraceutical industries due to its strong antioxidant capacity. In this study, the Escherichia coli strain CAR026 with completely balanced metabolic flow was selected as the starting strain for the production of astaxanthin. The expression of beta-carotene ketolase (CrtW) and beta-carotene hydroxylase (CrtZ), which catalyze the conversion of beta-carotene to astaxanthin, was coordinated, and a bottleneck was eliminated by increasing the copy number of crtY in CAR026. The resulting strain Ast007 produced 21.36 mg/L and 4.6 mg/g DCW of astaxanthin in shake flasks. In addition, the molecular chaperone genes groES-groEL were regulated to further improve the astaxanthin yield. The best strain Gro-46 produced 26 mg/L astaxanthin with a yield of 6.17 mg/g DCW in shake flasks and 1.18 g/L astaxanthin after 60 h of fermentation under fed-batch conditions. To the best of our knowledge, this is the highest astaxanthin obtained using engineered E. coli to date.