Volatile communication between fungi and bacteria

If you are small, smells are a good way to stand out. Soil microorganisms, such as bacteria and fungi, produce an array of pleasant or repelling odors, also known as volatile compounds. These compounds can easily travel through the abundant air- and water-filled pockets of the soil, mediating interaction and communication amongst physically separated microorganisms. Hence, volatiles play important roles in the microbial world. In this PhD thesis I explored how bacteria and fungi use volatiles to communicate with each other and studied the underlying mechanisms of such volatile dialogues. Fungal volatiles, in particular terpenes, showed to affect the ability of bacteria to move. But not only that; being exposed to a terpene-producing plant-pathogenic fungus, a beneficial bacterium started to produce its own terpenes. It is still unclear how often these dialogues take place with other microorganisms and plants. But since there are billions of other microorganisms, of which many have the genetic repertoire to produce terpenes, it seems likely that “terpene” is the most spoken language belowground. Thus, this thesis sets the basis for future research on microbe-microbe and plant-microbe interactions and, by understanding their ecological roles, for developments towards sustainable solutions for crop welfare.