Phylogenetic distribution in yeasts of the capacities for photoreactivation and for temperature-sensitive dark recovery following inactivation by ultraviolet radiation

Abstract

SARACHEK, A., and R. IRELAND. 1970. Phylogenetic distribution in yeasts of the capacities for photoreactivation and for temperature-sensitive dark recovery following inactivation by ultraviolet radiation. Can. J. Microbial. 16: 1187-1198.Eighty-three species of yeasts representing 12 perfect and 10 imperfect genera were tested for temperature-sensitive dark recovery and for direct photoreactivation after inactivation by ultraviolet radiation (uv). With the single exception of Torulopsis inconspicua, all species exhibit temperature-sensitive dark recovery. I n contrast, the ability to photoreactivate appears to be a genus-delimited characteristic. All test organisms unequivocally assignable to the genera Cryptococc~is, Debaryolnyces, Endomycopsis, Hansenula, Nadsonia, Rhodotorula, Saccl~aromyces, Sporobolomyces, Sporotrichum, and Trigonopsis photoreactivate. Photoreactivation was not observed among representatives of the genera Brettanomyces, Ha~aeniaspora, Kloeckera, Lipomyces, Nematospora, Pichia, Saccharomycodes, Schizosaccharomyces, or Schwanniomyces. The systematically heterogeneous genera Candida, Torulopsis, and Trichosporon include both photoreactivating and non-photoreactivating species. The evolutionary, radiobiological, and taxonomic significances of genus-independent temperature-sensitive dark recovery and of genusdependent photoreactivation are discussed.Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by University of Queensland on 11/17/14For personal use only.Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by University of Queensland on 11/17/14For personal use only.