Metabolic engineering a yeast to produce astaxanthin. (December 2017)

• Record Type: Journal Article
• Authors: Lin, Yu-Ju; Chang, Jui-Jen; Lin, Hao-Yeh; Thia, Caroline; Kao, Yi-Ying; Huang, Chieh-Chen; Li, Wen-Hsiung
• Is Part Of: Bioresource technology. Volume 245:Part A(2017)
• Page Start: 899
• Page End: 905
• Publication Date: 2017-12
• Subjects: Kluyveromyces marxianus -- Astaxanthin-biosynthesis genes -- Repeated genome integration -- Astaxanthin -- Site-directed mutagenesis; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2017.07.116
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: An astaxanthin-biosynthesis pathway was constructed in Kluyveromyces marxianus . Repeated genome integration of bkt and Hpchyb increased astaxanthin yield. Hpchyb was modified by site-directed mutagenesis to improve the enzyme activity. Our newly constructed strain can produce 3S, 3′S-astaxanthin at a high rate. Abstract: In this study, an astaxanthin-biosynthesis Kluyveromyces marxianus strain Sm23 was first constructed, which could produce 31 µg/g DCW astaxanthin. Then, repeated genome integration of the key astaxanthin biosynthesis genes Hpchyb and bkt was done to increase gene copy number and astaxanthin yield. Four improved strains were obtained and the yield of astaxanthin and the total yield of carotenoids in a strain increased with the copy numbers of Hpchyb and bkt . To improve the yield further, the gene Hpchyb from Haematococcus pluvialis was modified by site-directed mutagenesis to increase the enzyme efficiency or/and to prevent the heterologous protein degradation by ubiquitination. Using repeated-integration approach of bkt and the mutated Hpchyb into Sm23, the S3-2 strain was obtained and shown to produce the 3S, 3′S-astaxanthin at 9972 µg/g DCW in a 5 L fermentor.