471035 High-Throughput Screening of Biological H2 Production

Thursday, November 17, 2016: 9:06 AM
Continental 7 (Hilton San Francisco Union Square)
Jamin Koo1, Tim Schnabel1, Sylvie Liong2, Niklaus Evitt1 and James R. Swartz3, (1)Chemical Engineering, Stanford University, Stanford, CA, (2)Bioengineering, Stanford University, Stanford, CA, (3)Department of Chemical Engineering, Stanford University, Stanford, CA

Hydrogenases, ferredoxins (Fd), and ferredoxin-NADP+ reductases (FNR) are redox proteins that often mediate electron metabolism in vivo. These proteins are also potential components for biological H2 production technologies, but have not necessarily evolved for this application. Here, we report a High-throughput H2 Production Assay Device (H2PAD) that enables simultaneous evaluation of 96 individual H2 production reactions. Using a CCD camera, H2PAD senses the chemo-optical response of Pd/WO3 thin films to H2 produced in the individual wells of a 96-well plate. Image analysis software has been developed to interpret these time-lapse photographs. The resulting rates of color change indicate H2 production rates by the biological assays in the wells. We used H2PAD to discover hydrogenase and FNR mutants that can enhance biological H2 production. From a library of 10,080 randomly mutated Clostridium pasteurianum [FeFe] hydrogenase (CpI), we found a mutant with nearly 3-fold higher H2 production specific activity across a range of pH values. From a library of 400 semi-randomly mutated Oryza sativa (rice root) FNR (RrFNR), the top hit exhibited a 2-fold higher catalytic activity within an NADPH-driven H2 production pathway. In addition to accelerating the pace of directed evolution in biological H2-producing systems, H2PAD has the potential to elucidate fundamental biochemical mechanisms of these systems. As such, it represents a tool to allow research to more rapidly meet the growing global demand for sustainable H2.

Extended Abstract: File Not Uploaded