Increased carotenoid production by the food yeast Candida utilis through metabolic engineering of the isoprenoid pathway

• Published in: Applied and environmental microbiology Vol. 64; no. 7; pp. 2676 - 2680
• Main Authors: Shimada, H. (Tokyo Institute of Technology, Yokohama, Japan.), Kondo, K, Fraser, P.D, Miura, Y, Saito, T, Misawa, N
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01-07-1998
• Subjects: Animal, plant, fungal and microbial proteins, edible seaweeds and food yeasts; Biochemistry; Biological and medical sciences; Biotechnology; Candida - metabolism; CANDIDA UTILIS; Carotenoids - biosynthesis; Carotenoids - metabolism; Farnesyl-Diphosphate Farnesyltransferase - genetics; Food industries; Food Microbiology; Fundamental and applied biological sciences. Psychology; GENBANK/AB012603; GENBANK/AB012604; GENE; GENES; Genetic Engineering; Genetic technics; Hydroxymethylglutaryl CoA Reductases - genetics; HYDROXYMETHYLGLUTARYL-COA REDUCTASE; Methods. Procedures. Technologies; Microbiology; Modification of gene expression level; MOLECULAR SEQUENCE DATA; NUCLEOTIDE SEQUENCE; OXIDOREDUCTASES; OXIDORREDUCTASAS; OXYDOREDUCTASE; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; Yeast; Recombinant microorganism; Yeast; Gene overexpression; Biosynthesis; Metabolic pathway; Isoprenoid; Metabolism; Optimization; Fungi; Candida utilis; Food yeast; Gene; Production; Fungi Imperfecti; Mutation; Carotenoid; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.64.7.2676-2680.1998

The yeast Candida utilis does not possess an endogenous biochemical pathway for the synthesis of carotenoids. The central isoprenoid pathway concerned with the synthesis of prenyl lipids is present in C. utilis and active in the biosyntbesis of ergosterol. In our previous study, we showed that the introduction of exogenous carotenoid genes, crtE, crtB, and crtI, responsible for the formation of lycopene from the precursor farnesyl pyrophosphate, results in the C. utilis strain that yields lycopene at 1.1 mg per g (dry weight) of cells (Y. Miura, K. Kondo, T. Saito, H. Shimada, P. D. Fraser, and N. Misawa, Appl. Environ. Microbiol. 64:1226-1229, 1998). Through metabolic engineering of the isoprenoid pathway, a sevenfold increase in the yield of lycopene has been achieved. The influential steps in the pathway that were manipulated were 3-hydroxy methylglutaryl coenzyme A (HMG-CoA) reductase, encoded by the HMG gene, and squalene synthase, encoded by the ERG9 gene. Strains overexpressing the C. utilis HMG-CoA reductase yielded lycopene at 2.1 mg/g (dry weight) of cells. Expression of the HMG-CoA catalytic domain alone gave 4.3 mg/g (dry weight) of cells; disruption of the ERG9 gene had no significant effect, but a combination of ERG9 gene disruption and the overexpression of the HMG catalytic domain yielded lycopene at 7.8 mg/g (dry weight) of cells. The findings of this study illustrate how modifications in related biochemical pathways can be utilized to enhance the production of commercially desirable compounds such as carotenoids