Locating and exploiting electron divergence hotspots in the photosystem of green microalgae

With today’s ever-growing global population and rapid advances in technology, it has become more essential than ever to ensure energy and food supply for modern society. In the past decades, research has focused on exploiting photosynthesis to produce essentials such as biofuels or crop nutrients in a sustainable and economically favorable manner. Under specific conditions, the green biofuel hydrogen can be sustainably produced by green microalgae. The microorganism naturally conducts enzymatic reduction of protons powered by the photosynthetic electron transport chain. However, the raw hydrogen production yield is industrially insufficient. Hence, it has been of major interest to improve the yield by remodeling photosynthesis or, more specifically, redirecting more electrons from competing processes to hydrogen production. In this research, we introduce a novel and unsupervised method, called phage display, to discover strategic locations for exploiting electron divergence in favor of hydrogenase and therefore, generally, of enzymatic reduction processes. We find 12-amino-acid peptides that bind to the thylakoid membranes and to PSI. Using these peptides as a linker between hydrogenase and the photosynthetic machinery, we aim to connect the enzyme hydrogenase to the photosynthetic apparatus and boost hydrogen production to industrially significant levels.