Microbial co-cultures for production of methyl ketones from lignocellulose

Production of liquid transportation fuels from abundant and renewable lignocellulosic biomass represents a promising and sustainable alternative to present petroleum feedstock platforms. However, despite several decades of substantial efforts, commercialization of cellulosic biofuels has been limited and faces critical challenges, which include increased fossil fuel supply from hydraulic fracturing, poor economical returns from renewable energy/chemical investments, feedstock supply chain logistics, and overall high capital/operating costs due to technological barriers. This SBIR project aims to demonstrate the technical and economic feasibility of a new biochemical route that utilizes synthetic microbial consortia, consisting of co-cultures of cellulolytic fungi and metabolically engineered bacteria, for consolidated bioprocessing of lignocellulosic biomass to medium chain methyl ketones (MCMKs). These products are promising as renewable diesel blendstock and have existing markets as high-value specialty chemicals. In Phase I, the focus is to address critical early-stage technical risks, and to establish the basic feasibility of producing these chemicals via engineering and characterization of microbial co-cultures. Commercializing co-culture production of cellulosic MCMKs entails two aspects of development. Specifically, MCMK production will be integrated into a fungal-bacterial co-culture platform and the system will be further engineered towards economically viable performance. In parallel, MCMK fuel properties and specifications for specialty chemical applications will be validated and optimized. Biofuels produced from lignocellulosic biomass represents a promising alternative to petroleum fuels, however their commercialization still faces significant technical and economic barriers. This project aims to demonstrate the basic feasibility of a new biochemical route, based on microbial co-culture fermentation, for making cellulosic chemicals for diesel fuel and other applications. Commercial Applications and Other Benefits: Future Phase II and Phase III research & development will focus on aggressive strain and co-culture optimization to improve performance metrics, scale-up to reach commercial production, and full development of MCMKs for fuel applications. If successful, the proposed project will lead to a new cost- effective technology for consolidated bioprocessing of lignocellulosic biomass to advanced biofuels, which will generate many technical, economic, social, and environmental benefits to US public and globally. By offering improved profitability and co-revenues for cellulosic bio-refining, successful implementation of this technology will help drive commercialization of new cellulosic fuels and chemicals. As a result, significant environmental benefits will be achieved through reducing dependency on fossil fuels/feedstocks and through decrease in green-house gas emissions (GHG). Additionally, this could improve rural economies by creating new markets for crops and driving construction of new bio-refineries.