Valentiella maceioensis gen. et sp. nov. (Herpotrichiellaceae, Chaetothyriales), a new black yeast-like fungus isolated from bromeliads in Brazil

Abstract

Bromeliads have shown to be an excellent reservoir for fungi, especially yeasts and yeast-like fungi. Three strains were obtained from healthy leaves of Canistrum improcerum and Aechmea muricata (Bromeliaceae) in the Atlantic Forest of the Brazilian northeastern region. They were characterized morphologically, biochemically/physiologically, and based on the sequence-based phylogenetic species concept with analysis of the nrLSU and the ITS regions and the translation elongation factor EF-1 alpha (TEF1) gene. Based on our findings, a new genus, and species, namely, Valentiella maceioensis (Herpotrichiellaceae, Chaetothyriales, Ascomycota), was introduced for these isolates. The new taxa are mainly characterized by their black yeast-like morphology, with a mycelium consisting of torulose hyphae, conidiophores that were straight or slightly flexuous, septate, and chains of brown to dark brown fusoid-ellipsoid cells; conidiogenous cells fusoid-ellipsoid, 0–1-septate, brown to dark brown, having apical scars at the apex, and producing heads of conidia; conidia ellipsoid, subglobose to globose, light brown to brown with age, occasionally having basal scars. In the yeast-like phase, pseudohyphae and true hyphae are rarely formed while budding cells are present, and fermentation is not observed.