Unlocking the potential of fluorescent microbes: Exploring their ecological and industrial applications

Microbial world is invisible but offers potential and rare biomolecules with an array of hues, which pose multifaceted benefits to environment and humans. Among millions of known microbes from earth, very few microbial taxa are known to produce fluorescent molecules, which indicate their significance in science and industry. Some microbes are completely fluorescent, while some do not exhibit fluorescence externally but produces one or more intracellular fluorescent molecules with dim to bright or intense fluorescence. Fluorescent microbes produce either diffusible (extracellular/exogenous) or non-diffusible (intracellular/endogenous) fluorescent molecules on growth media. These fluorescent molecules benefit microbes in defence function and also offer a myriad of applications to humans. Studies on such microbes are still scarce and underexplored. This review treatises on the diversity, distribution, naturally couple bio-optical traits, and applications of fluorescent microbes (archaea, bacteria, cyanobacteria, and fungi), with special emphasis on bacteria, for further research and industrial applications. The research gaps on fluorescent microbes have been discussed to address their evolutionary origins, geographical distributions, and multifaceted applications.