Candida halmiae sp. nov., Geotrichum ghanense sp. nov. and Candida awuaii sp. nov., isolated from Ghanaian cocoa fermentations

During an investigation of the microbiology of Ghanaian cocoa fermentations, a number of yeast isolates with unusual pheno- and genotypic properties representing three possible novel species were isolated. Members of Group A divided by multilateral budding and ascospores were not produced. Group B strains produced true hyphae and ascospores were not produced. Group C representatives divided by budding and formed chains and star-like aggregates. Ascospores were not produced. Sequence analysis of the 26S rRNA gene (D1/D2 region) revealed that the Group A isolates were phylogenetically most closely related to Saturnispora mendoncae (gene sequence similarity 92.4 %), Saturnispora besseyi (88.8 %), Saturnispora saitoi (88.8 %) and Saturnispora ahearnii (88.3 %). Members of Group B were most closely related to representatives of the genera Dipodascus and Galactomyces and the asporogenous genus Geotrichum, but in all cases with 26S rRNA gene (D1/D2 region) similarities below 87 %. For Group C, the most closely related species were Candida rugopelliculosa (92.4 %), Pichia occidentalis (91.6 %) and Pichia exigua (91.9 %). The very low gene sequence similarities obtained for the three groups of isolates clearly indicated that they represented novel species. Repetitive Palindromic PCR (Rep-PCR) of the isolates and their closest phylogenetic relatives confirmed that the new isolates belonged to previously undescribed species. In conclusion, based on the genetic and phenotypic results, the new isolates were considered to represent three novel species, for which the names Candida halmiae (group A, type strain G3(T)=CBS 11009(T)=CCUG 56721(T)); Geotrichum ghanense (group B, type strain G6(T)=CBS 11010(T)=CCUG 56722(T)) and Candida awuaii (group C, type strain G15(T)=CBS 11011(T)=CCUG 56723(T)) are proposed.