Metschnikowia baotianmanensis f.a., sp. nov., a new yeast species isolated from the gut of the rhinoceros beetle Allomyrina dichotoma

Four strains, NYNU 15610, NYNU 15612, NYNU 15613 and NYNU 15615, of a novel ascomycetous yeast were isolated from the gut of Allomyrina dichotoma (Coleoptera: Scarabeidae) collected from two different localities in Henan Province, Central PR China. The four strains shared identical sequences in both of the D1/D2 domains of the large subunit rRNA gene and the internal transcribed spacer regions. Sequence analyses revealed that this novel species represents a member of the genus Metschnikowia. It differed from its closest known species Metschnikowia zobellii, Metschnikowiaaustralis and Metschnikowia bicuspidata, by 8.4-9.2% sequence divergence (33-40 nt substitutions and 7-12 gaps over 509 bases) in the D1/D2 sequences. The formation of ascospores was not observed on various sporulation media. In contrast to M. zobellii, M. australis and M. bicuspidata, the novel yeast species was unable to assimilate succinate, ethanol, ethylamine, cadaverine and 10% NaCl plus 5% glucose, but was able to grow in vitamin-free medium. The name Metschnikowia baotianmanensis f.a., sp. nov. is proposed to accommodate these strains, with NYNU 15613 as the holotype.