Nature
The Genus Trichoderma is a group of common filamentous fungi showing a wide range of phenotypes and interactions with other life forms (1). Trichoderma viride is the anamorph (asexual form) of the fungus Hypocrea rufa (teleomorph, the asexual form) (1, 2). T. viride can grow on a wide variety of substrates, including wood (from many plant species), soil, leaf litter, peat, bark, water-damaged buildings (2) and other moldy, damp buildings (3). It was isolated in 22% of surface-derived water samples, and frequently found throughout the water systems (4).
Most Trichoderma tipically produce copious large amounts of green conidia, organized in pustules (1-5 mm) or “lawns” when cultured in vitro. Pustules appear cottony, with individual fertile branches and conidiophores protruding beyond the surface. In cultures of T. viride, conidia often formed at the surface of a pustule and reached a deep-dark green color after a week. Various types of conidia are produced, though warted (i.e. presenting warts on the surface)(5), is the most common; size also varies, with a wide range of 3–5.5 by 2.8–5 μm. Optimal growth temperature was 25°C (2). T. viride colonies may have a coconut-like odor (5).
There is considerable overlap between peak fungal activity season and other allergens such as grass and weed pollens, often masking the pathology caused by fungal spores in multi-sensitized people (6). Trichoderma spp contributed on average to 0.23% of the total mold spores caught during a study spanning a 2-year period (7).
Trichoderma viride may prove to be a bio-control agent against plant pathogens (8), though it is not believed to produce antibiotics (5).
Taxonomy
Taxonomic tree of Trichoderma genus (9)
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Domain
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Eukaryota
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Kingdom
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Fungi
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Phylum
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Ascomycota
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Subphylum
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Pezizomycotina
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Class
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Sordariomycetes
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Order
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Hypocreales
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Family
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Hypocreaceae
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Genus
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Trichoderma
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Taxonomic tree of Trichoderma genus (9)
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Tissue
Spores release detectable amounts of allergens following germination (6, 7, 10). T. viride spores were more likely to be found in dust samples than air (11).
