Chemical interaction of endophytic fungi and actinobacteria from ce:italic>Lychnophora ericoides/ce:italic> in co-cultures

摘要

Microorganisms interact chemically in natural environments; however, the compounds and mechanisms involved in this phenomenon are still poorly understood. Using the cocultivation approach, changes in metabolic profiles due to interactions between endophytic fungal and actinobacterial strains isolated from the plantLychnophora ericoides(Asteraceae) were assessed. The production of the cytotoxic compound cytochalasin H by the fungusPhomopsissp. FLe6 was remarkably inhibited in solid and liquid co-cultures with the actinobacteriaStreptomyces albospinusRLe7. This was a consequence of the fungal growth inhibition caused by antifungal compounds produced byS. albospinusRLe7, including amphotericin B. Cytochalasin H is not toxic toS. albospinusRLe7, suggesting that this microorganism does not require a defense mechanism to prevent the potentially harmful effects of such fungal compound. By exhibiting various competitive phenotypes, these microbes can control each other’s growth when sharing an environment.