Microalgae have the potential to produce hydrogen through photosynthesis, making them a promising alternative to traditional fossil fuels. Although the progress in large-scale production is limited by biological constraints, such as low hydrogen production rates and sensitivity to environmental conditions, the bioengineering of microalgae is an important tool that will help overcome these limitations by enhancing hydrogen production efficiency and improving tolerance to varying environmental conditions. The review indicates the effectiveness of the inhibition of photosystem II (PSII), the introduction of oxygen-tolerant hydrogenase variants, and enhanced electron flow to hydrogenase enzymes as effective strategies to improve hydrogen production in microalgae. The role of integrated systems that combine hydrogen production with co-product generation, such as biofuels, bioplastics, or high-value metabolites, will enhance economic feasibility and sustainability. Also, advancements in bioreactor designs, coupled with real-time monitoring and control systems, create optimized environments that favor large-scale production. This integrated bioengineering approach not only maximizes biohydrogen potential, but also aligns with circular bioeconomy principles by minimizing waste and utilizing resources efficiently. Exploring new ways to enhance the integration of the use of microalgae for biohydrogen production and other valuable products will drive a more efficient and environmentally friendly bioprocess.
Sun et al. (Mon,) studied this question.