Fungal antibiotics control bacterial community diversity in the cheese rind microbiome

Abstract

ABSTRACTPotent antimicrobial metabolites are produced by filamentous fungi in pure lab cultures, but their ecological functions in nature are often unknown. Using an antibiotic-producingPenicilliumisolate and the cheese rind microbial community, we demonstrate that a fungal specialized metabolite can regulate the diversity of bacterial communities. Inactivation of the global regulator, LaeA, resulted in the loss of antibacterial activity in thePenicilliumisolate. Cheese rind bacterial communities assembled with thelaeAdeletion strain had significantly higher bacterial abundances than the wild-type strain. RNA-sequencing and metabolite profiling demonstrated a striking reduction in the expression and production of the natural product pseurotin in thelaeAdeletion strain. Inactivation of a core gene in the pseurotin biosynthetic cluster restored bacterial community composition, demonstrating the role of pseurotins in mediating bacterial community assembly. Our discovery demonstrates how antibiotic production can drive the assembly of microbiomes and provides an ecological context for widespread fungal specialized metabolites.