| Abstract: | Summary The dark pigmentation ofAureobasidium pullulans is due to melanin that stains the walls and may be heavily encrusted on the surface of older cells. The pigment granules can be shaken off ultrasonically. The melanin is quite impervious to ultraviolet light.Most strains ofA. pullulans observed secrete a viscous  mucin that encloses hyphae and spores in a matrix. In both hyphae and yeastlike blastospores, cross walls develop centripetally, and in many cases a pore is left in the cross wall, rendering possible protoplasmic movement and a heterokaryotic condition, which may account for the variability of the species. These wall pores are not like those found in Basidiomycetes.The blastospores contain droplets of lipid, and usually have but one nucleus though the few larger spores may have two or rarely three nuclei. The blastospores are not borne on stipules but bud from the parent cell in a manner similar to yeasts and leave behind a bud scar. |
