In the face of climate change, exploding world population and inevitable shortages in fossil resources within the next 50–100 years, it keeps getting harder and harder for agriculture to keep up with demand. Taken together with the fact that conventional chemical fertilisation destroys natural biomes, this calls for immediate action and alternatives.
One such possible alternative dwells underground, well hidden from the eye. An illustrious circle of soil fungi have been found to associate with nearly every terrestrial plant on earth, rendering them one of the key players in ecosystem stability and carbon sequestration. They interact with the plant’s roots and form a symbiosis commonly known as the mycorrhiza. These mycorrhizal fungi span vast mycelial networks, exploring the soil for minerals, which they exchange with the plant for photosynthesis products, like sugars. Furthermore, the symbiosis increases the plant’s resistance against soil pathogens, heavy metals or drought, reduces nutrient leaching and improves the environment for the establishment of fresh seedlings. The fungus acts as an elongation to the roots and stores large amounts of carbon, even beyond the plant’s life, remaining in a state of quiescence just waiting for the next plant to team up with.
In order to harness the fungus’ abilities, more basic research is needed. Their natural habitat is the intransparent soil, a complex environment with an enormous range of physical obstacles, nutrient and mineral gradients and numerous interacting species of each of nature’s kingdoms as well as their metabolites. In order to mimic these structures and simulate real-life conditions, which is impossible with conventional techniques, we set out to design our own microenvironment using so-called microfluidic technology.
In the past decades microfluidic technology has arisen as a new promising tool. In general, the field of microfluidics deals with the behaviour of fluids in miniature dimensions down to picoliters and involves the fabrication of microdevices for all kinds of tasks in biology or chemistry, either for analytics or synthesis. We can specifically tailor microenvironments to the task at hand, implanting physical obstacles, introducing chemical gradients or facilitating co-habitation with beneficial, hostile or just co-existing character. The applications are vast, stretching over investigations involving all kinds of environmental cues, chemical or physical, and their influence on the fungus.
With this new approach for basic mycorrhizal fungi research, we hope to understand these essential fungi and their symbiosis better, paving the way for new strategies in biofertilisation, as an alternative to conventional fertilisers based on fossil resources as well as sustainable forestry.