We describe Pichia deserticola and Candida deserticola, two species that have as their habitats necrotic tissues of Opuntia spp. and Stenocereus spp., respectively. Pichia deserticola, 21 strains of which were isolated, is homothallic and occurs in nature exclusively in the diploid state. It produces asci with two hat-shaped spores, which are rapidly released upon maturity. This species is nonfermentative and assimilates few carbon compounds. The guanine-plus-cytosine content range of the nuclear deoxyribonucleic acid (eight strains) is 27.4 to 28.4 mol%, and the average ± standard deviation for eight strains is 27.8 ± 0.4 mol%. Candida deserticola, 48 strains of which were isolated, has the same phenotypic properties and deoxyribonucleic acid base composition as P. deserticola, but lacks the ability to produce ascospores and is resistant to triterpene glycosides in growth media. The deoxyribonucleic acids of P. deserticola and C. deserticola show more than 96% homology, but the two species are separated geographically and by host plant. P. deserticola occurs in Opuntia species in southern Arizona and Texas, whereas C. deserticola is found almost exclusively in columnar cacti of the genus Stenocereus on certain Caribbean islands and in Baja California, Mexico. The type strain of P. deserticola is strain UCD-FST 83-467.3 (= ATCC 58091 = CBS 7119), and the type strain of C. deserticola is strain UCD-FST 76-355A (= ATCC 58088 = CBS 7121).
BarkerJ. S. F.,
TollG. L.,
EastP. D.,
MirandaM.,
PhaffH. J.1983; Heterogeneity of the yeast flora in the breeding sites of cactophilic Drosophila
. Can. J. Microbiol 29:6–14
HolzschuD. L.,
PresleyH. L.,
MirandaM.,
PhaffH. J.1979; Identification of Candida lusitaniae as an opportunistic yeast in humans. J. Clin. Microbiol 10:202–205
KircherH. W.1982; Chemical composition of cacti and its relationship to Sonoran Desert Drosophila
. 143–158BarkerJ. S. F.,
StarmerW. T.Ecological genetics and evolution, the cactus-yeast-Drosophila model system Academic Press Australia; Sydney:
KurtzmanC. P.,
PhaffH. J.,
MeyerS. A.1983; Nucleic acid relatedness among yeasts. 139–166SpencerJ. F. T.,
SpencerD. M.,
SmithA. R. W.Yeast genetics, fundamental and applied aspects Springer-Verlag; New York:
PriceC. W.,
FusonG. B.,
PhaffH. J.1978; Genome comparison in yeast systematics: delimitation of species within the genera Schwanniomyces, Saccharomyces, Debaryomyces, and Pichia
. Microbiol. Rev 42:161–193
SchildkrautC. L.,
MarmurJ.,
DotyP.1962; Determination of the base composition of deoxyribonucleic acid from its buoyant density in CsCl. J. Mol. Biol 4:430–433
StarmerW. T.,
PhaffH. J.1983; Analysis of the community structure of yeasts associated with the decaying stems of cactus. II. Opuntia species. Microb. Ecol 9:247–259
StarmerW. T.,
PhaffH. J.,
MirandaM.,
MillerM. W.1978; Pichia cactophila, a new species of yeast found in decaying tissue of cacti. Int. J. Syst. Bacteriol 28:318–325
StarmerW. T.,
PhaffH. J.,
MirandaM.,
MillerM. W.1978; Pichia amethionina, a new heterothallic yeast associated with decaying stems of cereoid cacti. Int. J. Syst. Bacteriol 28:433–441
StarmerW. T.,
PhaffH. J.,
MirandaM.,
MillerM. W.,
HeedW. B.1982; The yeast flora associated with the decaying stems of columnar cacti and Drosophila in North America. Evol. Biol 14:269–295
StarmerW. T.,
PhaffH. J.,
TredickJ.,
MirandaM.,
AberdeenV.1984; Pichia antillensis, a new species of yeast associated with necrotic stems of cactus in the Lesser Antilles, Int. J. Syst. Bacteriol 34:350–354
van der WaltJ. P.,
JohannsenE.1979; A comparison of interfertility and in vitro DNA-DNA reassociation as criteria for speciation in the genus Kluyveromyces
. Antonie van Leeuwen-hoek J. Microbiol. Serol 45:281–291
van der WaltJ. P.,
YarrowD.1984; Methods for the isolation, maintenance, classification and identification of yeasts. 45–104Kreger-van RijN. J. W.The yeasts—a taxonomic study North-Holland Publishing Co; Amsterdam: