Moniliella sojae sp. Nov., a species of black yeasts isolated from vietnamese soy paste (tuong), and reassignment of Moniliella suaveolens strains to Moniliella pyrgileucina sp. Nov., Moniliella casei sp. Nov. And Moniliella macrospora emend. comb. nov

The presence of yeasts at different steps of Vietnamese soy paste production was studied. Yeast growth occurred during primary soybean fermentation, with the cell density reaching 4.10⁶ c.f.u. ml^-1, and terminated during brine fermentation. The dominant species were Pichia kudriavzevii and Millerozyma farinosa. Over the span of 14 years, nine strains of Moniliella were isolated. The strains had identical PCR fingerprints generated with primer (GAC)₅ and identical D1/D2 and internal transcribed spacer (ITS) sequences. A D1/D2-based phylogeny indicated that the strains were closest to a group of four previously assigned as Moniliella suaveolens strains. Together they form a new lineage that is well separated from all known species, including M. suaveolens (over 12.7 % divergence). ITS sequences indicated the presence of four species differing from each other by 9-57 nt. The name Moniliella sojae sp. nov. is proposed to accommodate the strains isolated from Vietnamese soy paste, Moniliella pyrgileucina sp. nov. is proposed for PYCC 6800 and Moniliella casei sp. nov. is proposed for CBS 157.58. An emended combination Moniliella macrospora is proposed for CBS 221.32 and CBS 223.32. The type strains and MycoBank numbers are: M. sojae sp. nov., SS 4.2^T=CBS 126448^T=NRRL Y-48680^T and MB 822871; M. pyrgileucina sp. nov., PYCC 6800^T=CBS 15203^T and MB 823030; M. casei sp. nov., CBS 157.58^T=IFM 60348^T and MB 822872; M. macrospora emend. comb. nov., CBS 221.32^T (=MUCL 11527^T) and MB 822874.