Strategic use of microbial culture collections to empower drug discovery.

AIMS: Microbial natural products (NP) remain a major source of therapeutic agents. Microbial culture collections represent valuable reservoirs of unexplored bioactive compounds. This study aimed to evaluate the potential of two well-curated Brazilian microbial collections (CBMAI and LIF) for the identification of microbial strains with antifungal activity against clinically relevant fungal pathogens.

METHODS

Forty bacterial strains, mainly actinomycetes, derived from Brazilian and Antarctic biodiversity and preserved in the CBMAI collection were screened for antifungal activity against pathogenic fungi from the LIF collection using antagonism assays. The nine most promising strains were subsequently cultivated, and their crude extracts were evaluated by broth microdilution assays to determine minimum inhibitory and fungicidal concentrations.

RESULTS

Antifungal activity was observed in 28 strains (70%). Crude extracts from selected strains exhibited minimum inhibitory concentrations ranging from 0.125 to 1.5 mg/mL and fungicidal activity from 0.25 mg/mL to greater than 3 mg/mL, indicating broad and potent antifungal effects.

CONCLUSIONS

The results demonstrate that accessible screening approaches combined with the strategic use of well-maintained microbial culture collections enable the efficient identification of bioactive bacteria with potential applications in medicine and agriculture. These findings reinforce the role of microbial biobanks as essential infrastructure for drug discovery.