Dipodascus starmeri sp. nov., a new species of yeast occurring in cactus necroses.

In a previous publication describing the geographic distribution of yeasts associated with cactus necroses (W. T. Starmer, M.-A. Lachance, H. J. Phaff, and W. B. Heed, Evol. Biol. 24:253-296, 1990), 127 isolates were identified as strains of Candida ingens van der Walt et van Kerken on the basis of morphology and certain phenotypic characteristics. Here we show by using DNA hybridization and additional phenotypic properties that these strains were misidentified and that they represent a minimum of three separate species that can be differentiated from C. ingens and from each other by utilization of 2-propanol or acetone, sensitivity to digitonin, utilization of L-lysine as a sole nitrogen source, vitamin dependence, NaCl tolerance, lipolytic activity, and habitat. One of the new species is haploid and heterothallic, and its teleomorph represents the genus Dipodascus. We describe Dipodascus starmeri sp. nov. The phylogenetic relationship of D. starmeri with other members of the genus Dipodascus and its anamorph, the genus Geotrichum, was estimated from ribosomal DNA nucleotide sequence divergence. The type strain, a heterothallic haploid isolate, is UCD-FST 72-316 (= CBS 780.96 = ATCC 200546 = NRRL Y-17816). The complementary mating type is UCD-FST 81-513.3 (= CBS 781.96 = ATCC 200547 = NRRL Y-17817).