STTR Phase I: High-Yield Hydrogen Production from Biomass Sugars by Cell-Free Biosystems for Mobile Electricity Generation

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This Small Business Innovation Research Phase I project will scale up high-yield hydrogen production from maltodextrin and water mediated by cell-free enzymatic biosystems and develop prototype mobile electricity generators (MEGs). Cell-free biosystems for biomanufacturing (CFB2) implement complicated biochemical reactions in one pot by the in vitro assembly of more than three enzymes and/or cofactors. The Co-PI at Virginia Tech has demonstrated the production of nearly theoretical yields of hydrogen from sugars (including hexoses and pentoses) and water as CH2O (sugar) + H2O 2H2 + CO2 using CFB2. In this STTR I project, Cell-Free Bioinnovations Inc. will scale up enzymatic hydrogen production from a 2-mL bioreactor (current laboratory scale) to a 5-L bioreactor and integrate this process with a proton exchange membrane fuel cell stack for the high-efficiency generation of electricity. These integrated systems will charge numerous portable electronics and provide emergency power at low costs. The specific objectives are (i) scale-up of recombinant thermophilic enzyme production through high-cell density fermentation, (ii) discovery and production of more high-activity and ultra-thermostable enzymes, (iii) construction of synthetic enzyme complexes (metabolons) for easy purification and fast reaction rates, (iv) further enhancement of hydrogen generation rate by three fold, and (v) demonstration of prototype MEGs. The broader impact/commercial potential of this project is the scale-up of enzymatic production of hydrogen, which is mainly produced from natural gas and crude oil. Its satellite production facilities and its distribution are not widely available and are too costly. In the future, the production of low-cost, green hydrogen from local, renewable biomass sugars would create biomanufacturing and agricultural jobs in the bioeconomy, lower infrastructure costs for the hydrogen economy, decrease reliance on finite fossil fuels, and reduce net greenhouse gas emissions. Prior to large-scale production of economically competitive sugary hydrogen, several high-end applications are suggested for development to further improve the CFB2 platform, for example, MEGs, enzymatic fuel cells, and chiral compound synthesis. MEGs based on sugars will have some special markets. In addition, the new biotechnology platform CFB2 has unique advantages, such as higher product yields (i.e., neither by-product formation nor cell mass synthesis), greater engineering flexibility, faster reaction rates, broader reaction conditions (e.g., high temperature, low pH, organic solvent, toxic compound), and easier operation and control, compared with whole-cell fermentation. It is believed that the CFB2 platform could be used to produce jet fuels and long chain alcohols, store electricity, and fix CO2 in the future.