Chapter 17 - Babjeviella Kurtzman & M. Suzuki (2010)

Abstract

This chapter studies the genus Babjeviella. In the determination of asexual reproduction, cell division is by multilateral budding on a narrow base. Cells are short ellipsoid to elongate. Neither pseudohyphae nor true hyphae are formed. Colonies are butyrous with a glistening surface. In sexual reproduction, it is seen that Asci are unconjugated, and form one to four hat-shaped ascospores that are released by ascus deliquescence. Transmission electron microscopy has shown that bulb-like structures sometimes form on the brims of the ascospores. It is not known whether the species is homothallic or heterothallic. In physiology and biochemistry, it is seen that sugars are not fermented, but many of the sugars and polyols in standard yeast growth tests are assimilated. The major ubiquinone formed is CoQ-9, and the diazonium blue B test is negative. B. inositovora, the only known species in the genus, is one of only a few ascomycetous yeasts that can utilize myoinositol as a sole source of carbon. The type of species mentioned and accepted is Babjeviella inositovora. The systematic discussion of the species includes growth on 5% malt extract agar, growth on the surface of assimilation media, Dalmau plate culture on morphology agar, formation of ascospores, fermentation, CoQ, Mol% G1C, gene sequence accession numbers, type strain, cell carbohydrates, origin of the strains studied, type strain, systematics, ecology, biotechnology, agriculture and food, and clinical importance.