High-Throughput Screening of Catalytic H₂ Production

Area of Science:

• Biochemistry and Biotechnology
• Bioenergetics and Electron Transfer
• Enzyme Engineering

Background:

• Hydrogenases, ferredoxins, and ferredoxin-NADP+ reductases (FNR) are key redox proteins for biological electron metabolism and hydrogen (H2) production.
• Optimizing these proteins is crucial for advancing biological H2 production technologies.

Purpose of the Study:

• To develop and utilize a high-throughput screening device (H2 PAD) for identifying enhanced hydrogenase and FNR components.
• To discover novel enzyme variants with improved H2 production capabilities.

Main Methods:

• Development of a high-throughput H2 production assay device (H2 PAD) capable of evaluating 96 reactions simultaneously.
• Utilizing a CCD camera and image analysis to monitor chemo-optical responses of Pd/WO3 thin films to H2.
• Screening large libraries of randomly and semi-randomly mutated Clostridium pasteurianum [FeFe] hydrogenases and Oryza sativa FNR.

Main Results:

• Discovery of a Clostridium pasteurianum [FeFe] hydrogenase mutant with nearly 3-fold higher specific H2 production activity.
• Identification of an Oryza sativa FNR mutant that increased NADPH-driven H2 production rates by 60%.
• Demonstration of H2 PAD's efficacy in discovering performance-enhancing enzyme mutants.

Conclusions:

• The H2 PAD is an effective tool for high-throughput screening and discovery of improved biocatalysts for H2 production.
• Engineered hydrogenases and FNRs show significant potential for enhancing biological H2 generation.
• This platform can accelerate the development of sustainable H2 production technologies and aid in understanding enzyme mechanisms.