Phaffia rhodozyma and Xanthophyllomyces dendrorhous: astaxanthin-producing yeasts of biotechnological importance

The nutritional value of carotenoids such as α- and β-carotene, β-cryptoxanthin and astaxanthin has been known for many years, and their antioxidant properties and their efficiency in the prevention of certain human diseases have also been claimed.Accordingly, interest in these compounds from a nutritional aspect has increased substantially. Phaffia rhodozyma andXanthophyllomyces dendrorhous are the most promising industrial sources of astaxanthin. Since Phaffia was described in 1972, many studies of the phylogenesis, and biochemical and biotechnological properties of this red-pigmented yeast have been performed. The commercial demand for astaxanthin is increasing and, although biological production is still not economical, progress is being made in strain improvement and in fermentation methods