Ethanologenic/Electricigenic Consolidated Biprocessing of Cellulosic Biomass

Developing alternatives to fossil fuels is a major issue for the United States, as well as for the entire global economy. One alternative being aggressively pursued is the use of ethanol produced from renewable plant fiber. Plant fiber ,cellulose, which is contained in abundant resources such as wood pulp, agricultural wastes, and non-food crops such as switch grass and corn stover ¿ represents an attractive alternative to corn as a feedstock. Although this material can be biologically converted ,fermented, to ethanol, problems with the process currently make it too costly to be commercially feasible. In part, the problem is due to the generation of inhibitory organic acids, which cause low ethanol yields. This project seeks to combine fermentation with microbial fuel cell technology to reduce the amount of inhibitory acids produced and thereby increase the overall yield of ethanol from plant fiber. In Phase I, feasibility was proven by demonstrating a 5-fold increase in ethanol production and a 3-fold decrease in the amount of inhibitory acids relative to the ethanol produced. The objectives for Phase II include optimizing the system, matching the best biocatalysts with the best hardware, and testing at a scale that prepares the process for pilot-scale work and for a practical demonstration in Phase III. Commercial Applications and other Benefits as described by the awardee: The public is well aware of the increasing cost and competition for energy, and concern over the use of fossil fuels and climate change continues to increase. A cost-effective process that converts plant fiber to ethanol should lead to the delivery of alternative renewable fuels that are not based on fossil fuels