title: Photosensitization of the yeast Phaffia rhodozyma at a low temperature for screening carotenoid hyperproducing mutants.
abstract: Phaffia rhodozyma strain Ant-1 produces more carotenoids, known as antioxidants, but it was more sensitive to light plus toluidine blue O (TBO), a superoxide producer, than wild strain 67-385 at 20 degrees C. Carotenoid hyperproducing mutants (CHMs), Ant-1 and 2A2N, exhibited decreased activity of superoxide dismutase (SOD) compared to 67-385, and this is in part responsible for hypersensitivity of the mutants to photosensitization. Light plus TBO at 2 degrees C allowed carotenoid hyperproducing mutants to produce higher colony-forming units than the wild-type. Photosensitization with limited cell metabolism by a low temperature, provides an idea of selective conditions for carotenoid hyperproducers of P. rhodozyma.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors.forename: G H
authors.initials: GH
authors.lastname: An
mesh_terms: D002338:Carotenoids / Q000096:biosynthesis*; D003080:Cold Temperature; D005820:Genetic Testing / Q000379:methods*; D009154:Mutation; D017319:Photosensitizing Agents / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D014048:Tolonium Chloride / Q000494:pharmacology*; D015003:Yeasts / Q000235:genetics / Q000528:radiation effects*
chemical_list: D017319:Photosensitizing Agents; D014048:Tolonium Chloride; D002338:Carotenoids; D013482:Superoxide Dismutase