In nature, bacteria often form communities known as biofilms, where cells are embedded
in a self-produced extracellular matrix (ECM) that provides protection against external
aggressions or facilitates efficient use of resources. Interactions with other microbes can
significantly alter the structure of the community and thus the type of relationship with the
environment. Here, we study the role of different components of Bacillus ECM in the
adhesion to Botrytis hyphae, which could facilitate the efficient release of antifungal
metabolites. We also describe how the different purified components of the ECM and
certain Bacillus secondary metabolites (TasA, TapA, EPS, Fengycin) modulate the
chemical communication between Bacillus and Botrytis, altering the physiology and
ultrastructure of Botrytis.