Aureobasidium spp.

Genus/species: Aureobasidium spp.

Classification: Ascomycete

Morphology:
  • Cell: Yeast-like; vegetative growth predominantly hyphae over 3µm wide, hyaline, smooth, ellipsoidal, single celled, variable size/shape (7–17 × 3.5–7.0 µm), locally transformed into chlamydospores. Become brown (melanin formation). Budding frequent: Conidia form blastic or phialidic by swelling from mother cell; secondary conidia smaller than primary conidia, encased in slimy mass. Sometimes form endoconidia.
  • Colony: Malt agar:Fast growing: 25 mm diam in 7 days; colonies appear smooth and shiny due to abundant sporulation, pinkish with brownish central part, margin white, reverse yellowish; margin composed of superficial aerial mycelium; also light brown, yellow, pink or black.
  • WL: Unknown
  • Spore: Occasionally form chlamydospores; frequently form conidia.
  • Zygote: Anamorphic, does not reproduce sexually
  • Ascus: Rarely produced; reproduce by conidia (see morphology, cell).
  • Liquid Growth: unknown

Physiological Traits:

Assimilation of nitrate, glucose, cellobiose, galactose, maltose, mellobiose, raffinose, mannitol, erythritol (Senses-Ergul et al. 2006).


Ecological Traits:

Ubiquitous: plants, stone, wood, painted and damp surfaces; oligotrophic (Yurlova et al. 1999). Extremophilic; found in osmotically stressed environments, hypersaline salterns, glacial ice (Gostincar et al 2010; Zalar et al. 2008). Natural member of grape microflora (Fleet et al. 2003; Renouf et al. 2007).


Distinguishing Features:

Osmotolerant, saline tolerant, ubiquitous black fungus from the production of melanin pigmentation (Zalar et al. 2008).

Role in wine: Normal member of grape microflora (Fleet 2003). Natural biocontrol agent for Aspergillus and other grape vine pathogenic fungi (Dimakopoulou et al. 2008). Can degrade Ochratoxin A on grape berries (de Felice et al. 2008). Does not survive into wine (Renouf et al. 2007).


Sensitivities:

  • SO2: +
  • Sorbate: –
  • DMDC: +
  • pH: –
  • Acids:  –
  • Ethanol: –
  • Anaerobiosis: +
  • Heat:  >35˚C


References:

  • Dimakopoulou M, Tjamos SE, Antoniou PP, et al. 2008. Phyllosphere grapevine yeast Aureobasidium pullulans reduces Aspergillus carbonarius (sour rot) incidence in wine-producing vineyards in Greece. Biological Control 46 (2): 158-165
  • Fleet G. 2003. Yeast interactions and wine flavour. International Journal of Food Microbiology 86:11-22.
  • De Felice DV, Solfrizzo M, De Curtis F, Lima G, Visconti A, Castoria R. 2008. Strains of Aureobasidium pullulans Can Lower Ochratoxin A Contamination in Wine Grapes. Phytopathology 98(12):1261-1270.
  • Gostincar C, Grube M, de Hoog S, et al. 2010. Extremotolerance in fungi: evolution on the edge. FEMS Microbiology Ecology 71 (1): 2-11
  • de Hoog GS. 2000. Atlas of clinical fungi, 2nd ed. Washington, DC: American Society of Microbiology.
  • de Hoog GS, Yurlova NA. 1994. Conidiogenesis, nutritional physiology and taxonomy of Aureobasidium and Hormonema. Antonie van Leeuwenhoek 65: 41–54.
  • de Hoog GS. 1998. A key to the anamorph genera of yeastlike Archi- and Euascomycetes. In: Kurtzman CP, Fell JW, eds. The Yeasts, A Taxonomic Study. New York: Elsevier.
  • Renouf V, Claisse O, Lonvaud-Funel A. 2007. Inventory and monitoring of wine microbial consortia. Applied Microbiology and Biotechnology 75:149-164.
  • Senses-Ergul S, Agoston R, Belak A, Deak T. 2006. Characterization of some yeasts isolated from foods by traditional and molecular tests. International Journal of Food Microbiology 108:120-124.Yurlova NA, de Hoog GS, van den Ende AHGG. 1999. Taxonomy of Aureobasidium and allied genera. Studies in Mycology 43: 63-69
  • Zalar P, Gostincar C, de Hoog GS, et al. 2008. Redefinition of Aureobasidium pullulans and its varieties. Studies in Mycology 61:21-38.