Pichia antillensis, a New Species of Yeast Associated with Necrotic Stems of Cactus in the Lesser Antilles

Abstract

We describe Pichia antillensis, a new species of yeast which is closely related to Pichia opuntiae. Pichia antillensis, 20 strains of which were isolated, is heterothallic and occurs in nature in both the haploid state and the diploid state. It produces asci with four hat-shaped spores, which are rapidly released upon maturity. The guanine-plus-cytosine content of its nuclear deoxyribonucleic acid is 33.4 to 33.7 mol%. The deoxyribonucleic acids of Pichia antillensis and Pichia opuntiae var. opuntiae show approximately 50% homology, but the two species are not interfertile. Moreover, the two species are separated geographically and by host plant. Pichia antillensis occurs principally in necrotic tissue of the columnar cactus Cephalocereus royenii in the West Indies, and Pichia opuntiae var. opuntiae occurs in Opuntia rots in Australia. The type strain of P. antillensis is strain UCD-FST 82–651A (= ATCC 56267 = CBS 7111).