Characterization of a carotenoid-hyperproducing yeast mutant isolated by low-dose gamma irradiation.
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.
Sun
Namkyu
N
Department of Food Science and Technology, College of Agricultural and Life Sciences, Chungnam National University, Daejeon 305-764, South Korea.
Lee
Seunghee
S
Song
Kyung Bin
KB
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
D024341:Xanthophylls; D019207:beta Carotene; D002338:Carotenoids; C005948:astaxanthine