Overview
Trichoderma is a genus of filamentous ascomycete fungi ubiquitous in soil and plant root ecosystems. Best known as a biological control agent against plant pathogens, Trichoderma species produce an arsenal of hydrolytic enzymes and antimicrobial compounds. Rarely, they cause invasive infections in severely immunocompromised humans.
Metal Dependencies
Trichoderma species are prolific siderophore producers, synthesizing hydroxamate-type siderophores that sequester iron from the environment with high affinity. This iron-scavenging capacity is central to their biocontrol activity — they starve competing fungi of iron. They also require zinc for metalloprotease activity and copper for laccase-mediated lignin degradation.
Ecological Role
In soil, Trichoderma outcompetes pathogenic fungi through a combination of siderophore competition, direct mycoparasitism (attacking other fungi with chitinases), and antibiotic production. In the gut mycobiome, Trichoderma appears transiently through dietary exposure. Its siderophore production could theoretically modulate iron availability for gut bacteria, though this has not been systematically studied in vivo.
Conditions Associated
Invasive Trichoderma infections are rare, almost exclusively occurring in patients with severe immunosuppression (transplant recipients, peritoneal dialysis). T. longibrachiatum is the most commonly reported human pathogen in the genus. These infections can be difficult to treat due to variable antifungal susceptibility.
Cross-References
- iron — siderophore-mediated competition
- siderophore competition — core ecological strategy
- candida albicans — iron competition in polymicrobial contexts
- chitinase — mycoparasitic enzyme