title: Characterization of a carotenoid-hyperproducing yeast mutant isolated by low-dose gamma irradiation.
abstract: To isolate a carotenoid-hyperproducing yeast, Phaffia rhodozyma was treated by low-dose gamma irradiation below 10 kGy. Through repeated rounds of gamma irradiation and visual screening, a mutant 3A4-8 was isolated. It produced 3.3 mg of carotenoid per gram of yeast, 50% higher carotenoid content than that of the unirradiated strain. Glucose and peptone were the most suitable carbon and nitrogen sources for production of carotenoid based on the growth experiment of the mutant under various carbon and nitrogen sources. This result suggests that low-dose gamma irradiation could be used as a means of mutagenesis for isolation of a carotenoid-hyperproducing strain of P. rhodozyma because only the carotenoid-hyperproducing yeast survives gamma irradiation by scavenging oxygen radicals generated by radiolysis of water.
authors.affiliation: Department of Food Science and Technology, College of Agricultural and Life Sciences, Chungnam National University, Daejeon 305-764, South Korea.
authors.forename: Namkyu
authors.initials: N
authors.lastname: Sun
authors.forename: Seunghee
authors.initials: S
authors.lastname: Lee
authors.forename: Kyung Bin
authors.initials: KB
authors.lastname: Song
mesh_terms: D002338:Carotenoids / Q000096:biosynthesis*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D009154:Mutation; D024341:Xanthophylls; D015003:Yeasts / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000096:biosynthesis
chemical_list: D024341:Xanthophylls; D019207:beta Carotene; D002338:Carotenoids; C005948:astaxanthine