1. Combinatorial expression of different β-carotene hydroxylases and ketolases in Escherichia coli for increased astaxanthin production
- Author
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Panpan Yan, Zhiwen Wang, Xuewei Liu, Yuanqing Wu, Xueming Zhao, Tao Chen, and Ya-Jie Tang
- Subjects
Strain (chemistry) ,biology ,Operon ,medicine.medical_treatment ,Carotene ,Gene Expression ,Heterologous ,Bioengineering ,Xanthophylls ,medicine.disease_cause ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Fusion protein ,Mixed Function Oxygenases ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Astaxanthin ,Escherichia coli ,Oxygenases ,medicine ,Bacteria ,Biotechnology - Abstract
In natural produced bacteria, β-carotene hydroxylase (CrtZ) and β-carotene ketolase (CrtW) convert β-carotene into astaxanthin. To increase astaxanthin production in heterologous strain, simple and effective strategies based on the co-expression of CrtZ and CrtW were applied in E. coli. First, nine artificial operons containing crtZ and crtW genes from different sources were constructed and, respectively, introduced into E. coli ZF237T, a β-carotene producing host. Among the nine resulting strains, five accumulated detectable amounts of astaxanthin ranging from 0.49 to 8.07 mg/L. Subsequently, the protein fusion CrtZ to CrtW using optimized peptide linkers further increased the astaxanthin production. Strains expressing fusion proteins with CrtZ rather than CrtW attached to the N-terminus accumulated much more astaxanthin. The astaxanthin production of the best strain ZF237T/CrtZAs-(GS)1-WBs was 127.6% and 40.2% higher than that of strains ZF237T/crtZ As W Bs and ZF237T/crtZ Bs W Ps, respectively. The strategies depicted here also will be useful for the heterologous production of other natural products.
- Published
- 2019