Talaromyces mellisjaponici sp. nov., a xerophilic species isolated from honey in Japan

Abstract

Five isolates of a xerophilic Talaromyces species were obtained from honey in Japan. Molecular phylogenetic analysis based on a combined dataset for four regions (rRNA internal transcribed spacer, β-tubulin, calmodulin and RNA polymerase II second largest subunit) revealed that the strains formed an independent clade in section Trachyspermi, which is sister to Talaromyces affinitatimellis, Talaromyces basipetosporus and Talaromyces speluncarum. The strains and their relatives have different growth on creatine agar, yeast extract sucrose agar and dichloran 18 % glycerol agar, different branching patterns (mostly monoverticillate or biverticillate, less frequently divaricate or terverticillate), and different sizes and surface structures of conidia. Xerotolerance tests were also conducted using media adjusted to five different sucrose concentrations (0, 20, 40, 60 and 80 %). The colony diameters of the strains were larger than those of T. affinitatimellis, T. basipetosporus and T. speluncarum at each sucrose concentration. Altogether, the obtained morphological, molecular and physiological data allowed the proposal of Talaromyces mellisjaponici sp. nov. for this novel species, with NBRC 116048T as the type strain.