Sustainable bioenergy from waste: Photo‐fermentative production of biohydrogen and biomethane

Abstract The depletion of fossil fuels and their environmental impacts has accelerated the search for clean, sustainable energy alternatives. Photo‐fermentation has emerged as a promising approach for bioenergy generation, particularly in producing biohydrogen and biomethane from organic waste and wastewater. This article examines the biological and technological aspects of photo‐fermentative biohydrogen production, including feedstock selection, factors influencing yield, and strategies for optimization. It further explores photo‐fermentative biomethane production—an area less frequently reviewed—highlighting key processes and enhancement techniques. A comparative assessment of the two pathways addresses production mechanisms, feedstock efficiency, environmental benefits, and economic feasibility. The review identifies current challenges, recent advancements, and future directions for photobiological hydrogen and methane as sustainable energy sources.