Bacteria of the genus Streptomyces produce chemical substances called arginoketides, to which many other microorganisms react. Bacteria form biofilms, algae join together to form aggregates, and fungi produce signaling substances that they would not otherwise produce triggering new responses from other organisms.
Click here for original story, How Streptomyces bacteria produce signaling molecules, a mechanism of microbial communication in soil
Source: Phys.org