The Application of Microbial Consortia in a Biorefinery Context: Understanding the Importance of Artificial Lichens

The exchange of nutrients among different species is one of the most complex, intriguing, and important factors that favored the development of certain microorganisms in evolutionary systems. As a direct result of this, microorganisms in natural system often co-exist with many others in an organized manner. From an engineering approach, the benefits of having multiple microorganisms in a bioprocess may be beneficial to a number of reasons, including favoring the preferred metabolic pathways of one organism, simultaneously by promoting other additional effects by another. Among the many examples of microbial communities or consortia, one of the most studied from a biological point of view are known as lichens—a combination of fungi and algae and/or cyanobacteria. Adding to the fact that over one fifth of all fungal species today known to be in its lichenized form, it is crucial to understand the hidden benefits that such combination can offer to biosystems engineers. Fungal-algal symbiotic relationships often offer significant and efficient exchange of gases, promoting a healthy growth, and can be directly applied towards the solution of a wide range of issues faced today by biorefineries. This chapter summarizes some of the applications of this novel, yet promising, concept, including algal harvesting, lipid accumulation, and bioremediation of wastewater, presenting also a brief history and perspectives on the concept.