Seventy-one strains were isolated from the River Agrio–Lake Caviahue acidic aquatic environment in Argentina. Strains were isolated mainly from the most acidic section of the river (pH 1.8–2.7). According to the mini/microsatellite-primed PCR technique and physiological data, these strains are representatives of a single novel species of the genus Cryptococcus. Analysis of the D1/D2 region of the large-subunit rRNA gene showed that the strains belong to the order Filobasidiales of the subphylum Agaricomycotina. The novel isolates formed a phylogenetic group with Cryptococcus ibericus, Cryptococcus aciditolerans and Cryptococcus metallitolerans, the most closely related species. This group, which is phylogenetically related to the Gastricus clade, is considered to be an ecoclade due to its peculiar ecology and physiology. The name Cryptococcus agrionensis sp. nov. is proposed to accommodate these isolates, with strain CRUB 1317T (=CBS 10799T=JCM 15321T) as the type strain.
A novel species of ascomycetous yeast, Pichia insulana sp. nov., is described from necrotic tissue of columnar cacti on Caribbean islands. P. insulana is closely related to and phenotypically very similar to Pichia cactophila and Pichia pseudocactophila. There are few distinctions between these taxa besides spore type, host preference and locality. Sporogenous strains of P. insulana that produce asci with four hat-shaped spores have been found only on Curaçao, whereas there was no evidence of sporogenous P. cactophila from that island. In addition, sequences of the D1/D2 fragment of the large-subunit rDNA from 12 Curaçao strains showed consistent differences from the sequences of the type strains of P. cactophila and P. pseudocactophila. The type strain of P. insulana is TSU00-106.5T (=CBS 11169T =UCD-FST 09-160T).