Dothideales » Saccotheciaceae » Aureobasidium

Aureobasidium pullulans

Aureobasidium pullulans (de Bary & Löwenthal) G. Arnaud, Annals d'École National d'Agric. de Montpellier, Série 2 16(1-4): 39 (1918) [1917].

Index Fungorum number: IF 101771; Facesoffungi number: FoF00099, Fig. 1

Description:

Colonies on MEA at 25 ºC attaining 50−90 mm diam., after 14 days, appearing smooth and slimy due to abundant sporulation, pinkish white. Within first 5 weeks colonies are filamentous developing into white, setae-like mycelia becoming brown initially and then black at the irregular margin. Sexual morph: Unknown. Asexual morph: Vegetative hyphae hyaline, transversely septate, smooth, sometimes becoming brown to dark brown when mature, smooth, thin-walled, 2−9 μm wide, transversely septate. Conidiogenous cells undifferentiated, intercalary or terminal on hyaline hyphae or arising as short lateral branches. Conidia 5.5−18 × 3−6 µm (x̄ = 10.2 × 4.8 µm, n = 20), produced synchronously in dense groups from small denticles, and also formed percurrently on short lateral denticles, hyaline sometimes becoming brown, ellipsoidal, aseptate, smooth. Endoconidia are produced by an intercalary cell.

Material examined: Thailand, Chiang Rai, on malt extract agar, 5 May 2021, dried (MFLUCC 14−0288, ICMP 20350).

Fig. 1. Aureobasidium pullulans (MFLUCC 14−0288). a, b Culture on MEA incubated for 4 weeks. c–h Conidiophores and conidiogenesis. i–k Conidia. Scale bars: c = 20 μm, d–h = 10 μm, i–k = 5 μm.

Importance and distribution

Aureobasidium species are parasitic and saprobic on wide range of hosts and some taxa are pathogenic to humans. Some taxa are allergens causing allergic reactions by producing significant mycotoxins (Taylor et al. 2006). Aureobasidium pullulans can cause phaeohyphomycosis, keratomycosis, pulmonary mycosis with sepsis and cutaneous mycoses such as dermatitis and several other infections (Alami et al. 2022). There are 46 Aureobasidium epithets in Index Fungorum (2022) but several species have been transferred to other genera such as Alternaria, Dothiora, Exophiala, Kabatiella and Microdochium. Aureobasidium comprises 26 species known on wide range of hosts such as Abies (Pinaceae), Acer sp. (Sapindaceae), Avena sativa (Poaceae), Bambusa sp. (Poaceae), Celosia cristata (Amaranthaceae), Convallaria majalis (Asparagaceae), Dactylis glomerata (Poaceae), Hemerocallis sp. (Asphodelaceae), Leucospermum conocarpodendron (Proteaceae), Linum (Linaceae), Maianthemum bifolium (Asparagaceae), Olea europaea (Oleaceae), Phoenix dactylifera (Arecaceae), Pinus (Pinaceae), Polygonatum multiflorum (Asparagaceae), Protea (Proteaceae), Ribes (Grossulariaceae), Secale cereale (Poaceae), Trifolium pratense (Fabaceae), Umbellularia californica (Lauraceae), Vicia (Fabaceae), Viscum (Santalaceae) and Zea mays (Poaceae) amongst others. Aureobasidium has worldwide distribution.

Industrial relevance and applications

Aureobasidium has antagonistic activity against several post-harvest pathogens and is useful for the agricultural industry (Bozoudi and Tsaltas 2018). Aureobasidium also has an effect on mycotoxin biocontrol through several methods, such as binding or absorption (Castoria et al. 2001). Aureobasidium pullulans strains also produce a wide range of industrial enzymes, such as β-glucosidase, amylases, cellulases, lipases, proteases, xylanases and mannanases (Bozoudi and Tsaltas 2018).

Quarantine significance

Aureobasidium is of quarantine significance and was found from asymptomatic seed (Dugan and Rector 2007).

Biochemical importance of the genus, chemical diversity or applications

Aureobasidium produces several chemicals such as volatile organic compounds, hydrolytic enzymes, antimicrobial compounds (antibacterial and antifungal) and polysaccharides such as pullulan amongst others (Pouliot et al. 2005; Thirumavalavan et al. 2010).

References

Alami S, Sekkal I, Aoufi S, Lyagoubi M, Benzekri L, Senouci K. 2022 – Subcutaneous phaeohyphomycosis caused by Aureobasidium Pullulans in an immunocompetent carpenter. Medical Mycology Case Reports 36, 1–4.

Arnaud G. 1910 – Contribution à l'étude des Fumagines. 1. Annales de l'École Nationale d'Agriculture de Montpellier Series 2, 9, 239–277.

Bozoudi D, Tsaltas D. 2018 – The Multiple and Versatile Roles of Aureobasidium pullulans in the Vitivinicultural Sector. Fermentation 4, 85.

Castoria R, De Curtis F, Lima G, Caputo L, Pacifico S, De Cicco V. 2001 – Aureobasidium pullulans (LS-30) an antagonist of postharvest pathogens of fruits: Study on its modes of action. Postharvest Biology and Technology 22, 7–17.

Ciferri R. 1958 – Man Mic Med, edn 2 (Pavia) 1, 178.

Dugan FM, Rector RG. 2007 – Mycoflora of seed of common teasel. (Dipsacus fullonum) in Washington State. Pacific Northwest Fungi 2, 1–10.

Hermanides-Nijhof EJ. 1977 – Aureobasidium and allied genera. Studies in Mycology 15, 141–222.

Hongsanan S, Hyde KD, Phookamsak R, Wanasinghe DN et al. 2020a – Refined families of Dothideomycetes: Dothideomycetidae and Pleosporomycetidae. Mycosphere 11,1553–2107.

Pouliot JM, Walton I, Nolen-Parkhouse M, Abu-Lail LI, Camesano TA. 2005 – Adhesion of Aureobasidium pullulans Is Controlled by Uronic Acid Based Polymers and Pullulan. Biomacromolecules 6, 1122–1131.

Taylor P, Esch R, Flagan R, House J, Tran L, Glovsky M. 2006 – Identification and Possible Disease Mechanisms of an Under-Recognized Fungus, Aureobasidium pullulans. International archives of allergy and immunology 139, 45–52.

Thambugala K, Ariyawansa H, Li Y, Boonmee S et al. 2014 – Dothideales. Fungal diversity 68, 105–158.