Li Shun, Huang Jun-Chao
Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Nat Prod Bioprospect. 2018 Oct;8(5):397-403. doi: 10.1007/s13659-018-0172-z. Epub 2018 Jun 6.
Astaxanthin is a value-added ketocarotenoid with great potential in nutraceutical and pharmaceutical industries. Genetic engineering of heterologous hosts for astaxanthin production has attracted great attention. In this study, we assessed some key factors, including codon usage of the expressed genes, types of promoters, bacterial strains, and culture media, for engineered Escherichia coli to produce astaxanthin. The effect of codon usage was shown to be related to the types of promoters. E. coli DH5α was superior to other strains for astaxanthin production. Different culture media greatly affected the contents and yields of astaxanthin in engineered E. coli. When the expression cassette containing GadE promoter and its driving genes, HpCHY and CrBKT, was inserted into the plasmid pACCAR16ΔcrtX and expressed in E. coli DH5α, the engineered strain was able to produce 4.30 ± 0.28 mg/g dry cell weight (DCW) or 24.16 ± 2.03 mg/L of astaxanthin, which was a sevenfold or 40-fold increase over the initial production of 0.62 ± 0.03 mg/g DCW or 0.61 ± 0.05 mg/L.
虾青素是一种具有附加值的酮类胡萝卜素，在营养保健品和制药行业具有巨大潜力。利用异源宿主进行虾青素生产的基因工程已引起广泛关注。在本研究中，我们评估了一些关键因素，包括表达基因的密码子使用情况、启动子类型、细菌菌株和培养基，以探究工程化大肠杆菌生产虾青素的情况。结果表明，密码子使用情况的影响与启动子类型有关。大肠杆菌DH5α在虾青素生产方面优于其他菌株。不同的培养基对工程化大肠杆菌中虾青素的含量和产量有很大影响。当将含有GadE启动子及其驱动基因HpCHY和CrBKT的表达盒插入质粒pACCAR16ΔcrtX并在大肠杆菌DH5α中表达时，该工程菌株能够产生4.30±0.28毫克/克干细胞重量（DCW）或24.16±2.03毫克/升的虾青素，相较于初始产量0.62±0.03毫克/克DCW或0.61±0.05毫克/升分别提高了7倍或40倍。
