Light-mediation as a strategy to induce production of valuable microbial compounds

Microorganisms are highly valued for their production of valuable natural compounds. These microbial-based compounds are often with multiple bioactivities, demonstrating antimicrobial, anti-tumour, and antioxidant attributes, among others. The yield of the compounds is, however, typically low and insufficient to supplement large-scale extraction and purification. To address this limitation, several strategies have been attempted to enhance the production of microbial-based compounds. These include optimization of media composition, genetic level modifications, and modifications to external stimuli. This review emphasizes on the role of light, an external stimuli, in enhancing the production of microbial-based compounds. The use of light as a regulating factor is clearly a more environmental-friendly and low-cost approach than the modification of other regulating factors. In this chapter, the major types of microbial compounds, factors regulating the production of microbial compounds, influence of light on the production of microbial compounds, mechanisms regulating light mediation, and applications for light mediation are discussed.