Tremella saccharicola f.a., sp. nov., a novel tremellaceous yeast species isolated from tropical regions

Ten strains representing a single anamorphic novel yeast species were isolated from the external surface (DMKU-SP23 and DMKU-SP40) and tissue (DMKU-SE89, DMKU-SE99, DMKU-SE100 and DMKU-SE147) of sugarcane leaves in Thailand, and phylloplane (IMUFRJR 52034) and rhizoplane (IMUFRJ 52036 and 52037) of sugarcane and associated soil (IMUFRJ 52035) in Brazil. These strains showed zero to two nucleotide substitutions in the sequences of the D1/D2 region of the LSU rRNA gene and zero to three nucleotide substitutions in the internal transcribed spacer (ITS) region. Tremella globispora was the most closely related species, but with 1.7-2.1 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 5.3-6.0 % nucleotide substitutions in the ITS region. Phylogenetic analysis based on the concatenated sequences of the ITS and the D1/D2 regions showed that these 10 strains represented a single species belonging to the genus Tremella (class Tremellomycetes, subphylum Agaricomycotina) that was distinct from related species. They therefore represented a novel species of the genus Tremella although the formation of basidia and basidiocarp were not observed. The name Tremella saccharicola f.a., sp. nov. is proposed. The type strain is DMKU-SP23(T) (=NBRC 109698 T =BCC 61186(T)).