SusChEM: Design of Ionic-Liquid-Biocatalyst Systems for Production of Platform Chemicals and Intermediates Directly from Plant Biomass

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

In the future, for biorefineries to operate economically, they will require an integrated process with the complete use of all carbons in the lignocellulosic biomass including cellulose, hemicellulose, and lignin to produce biofuels, biochemicals, and biomaterials. Biomass is difficult to process, however. Ionic liquid (IL) pretreatment is an emerging technology that aids biomass processing. For its successful commercialization, this technology must overcome significant barriers, namely cost of the ILs, recycling expense, and general toxicity to biocatalysts. To tackle these barriers, the objective of the proposed research is to develop novel highly-compatible IL-biocatalyst systems for simultaneous saccharification and fermentation (SSF-IL) of lignocellulosic biomass into high-value organic chemicals (HVOs). Specifically, the team will fundamentally study and optimize high IL-tolerance of Yarrowia lipolytica, a generally regarded-as-safe oleaginous yeast, that can thrive and perform efficient biotransformation in at least a 10% IL solution. The team will also elucidate and optimize Y. lipolytica metabolism for efficient co-utilization of glucose and xylose, the major sugars of lignocellulosic biomass. Finally, the team will develop highly compatible IL-biocatalyst systems for enhanced conversion of lignocellulosic hybrid poplar (a potential bioenergy crop), into high-value organics, specifically alpha-ketoglutaric acid via SSF-IL. The project will gain fundamental understanding of how the engineered IL-biocatalyst system can transform recalcitrant biomass into valuable biofuels, biochemicals, and biomaterials, and demonstrate a model for an unconventional, economical, and competitive integrated biorefinery. It will present a promising sustainable pathway for energy independence, security, and a greener environment by utilizing renewable, sustainable, and domestic lignocellulosic biomass instead of fossil fuels. The project will also provide educational components including training of postdoctoral, graduate and (underrepresented minority) undergraduate students in the areas of biomass conversion, biocatalysis, systems biology, and metabolic engineering. In addition, outreach will involve engaging undergraduate students in the Internationally Genetically Engineered Machinery (iGEM) program that the PI has organized since 2012 as well as organizing summer workshops for K-12 students who will be exposed to various aspects of Catalysis and Biocatalysis to address challenging energy-related problems. The project is co-funded by the NSF Experimental Program to Stimulate Competitive Research (EPSCoR).