Toxic Peptides from common indoor Trichoderma Mold

Several studies have suggested that allergy to Trichoderma may be an important trigger for asthma development.

Trichoderma molds are known to produce a group of mycotoxins composed of small peptides (proteins) which are call peptaibiols. Peptaibiols are small peptides of 4 to 21 amino acids and have a high content of uncommon amino acids such as ά-aminoisobutyric acids. A Finnish study examined the effects of cell extracts from 8 strains of the mold Trichoderma longibrachiatum on mammalian cells. These 8 strains were obtained from 2 clinical samples, 3 soil samples and 3 samples from sick buildings. These 8 strains of T. longibrachiatum were found to produce large quantities of peptaibols, which comprised about 0.5 to 2.6% of the total fungal mass. Each culture petri dish contained from 1,500 to 8,800 micrograms of peptaibols. Concentrations of mixed peptaibols as low as 0.6 parts per million (0.6 micrograms per milliliter) were very toxic to boar sperm cells. These peptaibols are very toxic to cells by opening sodium and potassium permeable holes in the membranes of mammalian cells. Further research on the health effects of mold-produced peptaibols is needed.

Raimo Mikkola et al. 20-residue and 11-residue peptibols from the fungus Trichoderma longibrachiatum are synergistic in forming Na+/K+ – permeable channels and adverse actions toward mammalian cells. FEBS Journal, 2012 In Press.