Multiple promoters driving the expression of astaxanthin biosynthesis genes can enhance free-form astaxanthin production

• Published in: Journal of microbiological methods 2019-05, Vol.160, p.20-28
• Main Authors: Chou, Yi-Li, Ko, Chia-Yun, Yen, Chih-Chung, Chen, Long-Fang O., Shaw, Jei-Fu
• Format: Article
• Language: English
• Subjects: Astaxanthin; Escherichia coli; Multiple promoters
• ISSN: 0167-7012; 1872-8359
• DOI: 10.1016/j.mimet.2019.03.012

Astaxanthin possesses various biological properties and is used in the animal and fish feed, food, and beverage industries. In this study, we derived zeaxanthin biosynthesis genes (crtE, crtB, crtI, crtY, and crtZ) from Erwinia uredovora and crtW from Agrobacterium aurantiacum. We fused inducible and constitutive promoters to astaxanthin biosynthesis genes to construct a novel plasmid (dubbed PTP3-6) that can effectively enhance free-form astaxanthin (FFAX) production. The PTP3-6 plasmid contains one T7 promoter, driving IPTG inducible crtW expression, and three constitutive promoters (isolated from E. uredovora) driving expression of the other zeaxanthin biosynthesis genes. Escherichia coli BL21 (DE3) cells carrying the PTP3-6 plasmid produced 8.3 mg/g dry cell weight astaxanthin, which is 69.4-fold higher than has been previously reported. Using multiple promoter fusions of astaxanthin biosynthesis genes could be applied in other hosts to enhance astaxanthin production. FFAX was identified in recombinant E. coli cells through ultra-performance liquid chromatography-mass spectrometry. [Display omitted] •The novel plasmid contained the multiple promoters operated gene expression at different times.•The amount of astaxanthin produced in recombinant E. coli cells was 69.4-fold higher than that reported in previous study.•The recombinant E. coli cells can effectively enhance free-form astaxanthin production.