Bacteria "Read" Light To Gain a Competitive Advantage.

Photosynthesis, the process of converting solar energy into stored chemical bonds, represents the primary mechanism by which biological organisms utilize photons. Light can also be used to activate a number of photosensory compounds and proteins designed to carry out tasks, such as DNA repair, gene regulation, and synchronization with the diurnal cycle. Given that sunlight is incident upon many environments, it is not farfetched to think that life may have evolved other as-yet-undetected mechanisms to profit from solar irradiation. In this issue, Maresca and coworkers detail their observations of light-enhanced growth of several nonphotosynthetic actinobacteria, as well as describe the potential photosensitizer responsible for this phenotype and discuss the regulatory networks involved (J. A. Maresca, J. L. Keffer, P. P. Hempel, S. W. Polson, et al., J Bacteriol 201:e00740-18, 2019, https://doi.org/10.1128/JB.00740-18). This study opens the door to many intriguing questions about the use of light as information in nonphotosynthetic biological systems.