Biofuels and biochemicals derived from biomass represent a synthetic alternative that uses abundant and renewable lignocellulosic resources, which do not require food-crop feedstocks. Cellulose and hemicellulose found in biomass must first be converted to fermentable sugars for subsequent conversion into fuels and chemicals by fermentative organisms. The efficiency of state-of-the-art bio-conversion pathways is reduced by factors like intermediate and end-product toxicity to fermentative organisms, diversion of carbon to biomass formation, and co-production of undesired byproducts. A solution is the elimination of fermentative organisms for only their isolated metabolic pathways, but such in vitro enzymatic systems typically suffer from low productivities. Researchers at the National Renewable Energy Laboratory have developed acellular enzymatic polypeptide scaffolds that can efficiently degrade biomass and produce fuels or chemicals with single enzymatic units.
The National Renewable Energy Laboratory’s enzymatic polypeptide scaffolds overcome the limitations of state-of-the-art microbial biocatalyst technology through a combination of a synthetic metabolome with a synthetic cellulosome into a homologous single module that degrades biomass and yields desired fuels or chemicals. The technology takes advantage of the type and species specificity of the dockerin-cohesin protein pairs found in nature. These pairs are linked to either cellulases or metabolic enzymes that are assembled on two distinct scaffolds. Linked by linker peptides, the scaffolds form the final synthetic proteome. This architectural approach offers intrinsic flexibility in functionality by allowing accessible tailoring of the synthetic proteome to be specially suited for particular types of biomass feedstocks, reaction products, or conversion processes.
To learn more about Synthetic Proteomes for Direct Conversion of Biomass to Biochemicals and Fuels, please contact Eric Payne at:
Applications and Industries
- Biofuels such as biodiesel
- Chemicals or chemical intermediates such as 3-hydroxypropionic acid, 1,3-propanediol, 2,3-butanediol, alkenes, nootkatone, or gluconic acid
- Polymers, monomers, and chemical precursors such as 3-hydroxypropionic acid, acrylic acid, acrylamide, acrylonitrile, methyl acrylate, or malonic acid
- Enhanced thermal stability and easier product recovery via surface targeting or advanced reactors with advantageous designs
- Protein recycling via functionalization with tags for expedited recovery
- Enabling of consolidation of heterologous metabolic pathways in microorganisms for in vivo production of biofuels and biochemicals
- Reduction of the loss of product intermediates along proteome metabolic pathways
- Minimization of the production of toxic inhibitory compounds produced naturally by cell metabolism
- Consolidation of promising synthetic proteomes into a single gene product for multifunctional enzymatic catalytic behavior