Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** the goal of this project is to…

Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** the goal of this project is to produce advanced biofuel and specialty chemicals (n-butanol, butyrate, and butyl butyrate) from agricultural residues in an integrated bioprocess. Butanol is an industrial solvent and also an attractive biofuel with superior fuel properties (higher energy density, lower volatility, etc.) than ethanol. Butyric acid is a specialty chemical widely used in food, chemical and pharmaceutical industries. The use of butyrate in animal feed to replace antibiotics is also expanding rapidly in the animal feed market. Both butyric acid and butanol can be produced biologically from biomass, which, however, is not economically viable because conventional fermentation processes are limited by severe product inhibition, low product yield and titer, and difficulty in product recovery and purification.to solve these problems, we have engineered clostridium tyrobutyricum for butyrate and butanol production from glucose and xylose present in lignocellulosic biomass hydrolysates. Also, adaptive evolutionary engineering was applied to increase cell tolerance to toxic compounds present in the fermentation broth. In this project, fermentation processes will be optimized and integrated with in situ product separation to alleviate product inhibition and further increase productivity and yield. In addition, we will also develop a novel immobilized enzyme reactor and an extractive fermentation-esterification process for converting fermentation-produced butyric acid and butanol to butyl butyrate, a higher-value flavoring compound used in the food industry. IT can also be used as a biofuel and oxygenator to enrich biodiesel. The engineered c. Tyrobutyricum can produce butyric acid and butanol at high titers, yields, and productivities for economical production of these chemicals, and are superior to conventional solventogenic clostridia widely used in the ABE fermentation. Also, in situ esterification with exogenous lipase in extractive fermentation can further increase reaction rate and conversion due to the removal of inhibitory products. These process concepts have not been investigated for industrial applications before. By applying these innovative technologies, butyric acid, n-butanol, and butyl butyrate can be produced economically in an integrated biorefinery.