I-Corps: Lignin-Derived Antimicrobials to Control Bacterial Contamination in Fuel Ethanol Fermentation

Project Title: Exploring the commercialization of lignin-derived antimicrobials to control bacterial contamination in fuel ethanol fermentation Entrepreneurial Lead (EL): Mr. Ryan Kalinoski, [email protected] Qualifications: The EL is currently a fourth-year doctoral student in the Department of Biosystems and Agricultural Engineering at the University of Kentucky and is expected to graduate December 2020. His research focuses on evaluating the antimicrobial properties of lignin derived compounds and materials produced through different thermochemical depolymerization techniques. His role will be to investigate the commercial potential for the lignin-derived antimicrobials. Technical Lead (TL): Dr. Jian Shi, [email protected] Qualifications: The TL is an assistant professor in the Department of Biosystems and Agricultural Engineering at the University of Kentucky, Lexington, KY. Dr. Shi has 15 yearsf experience both in industry and academia with expertise in lignin valorization, bioprocessing, and fermentation. He will serve as the Principal Investigator and will have ultimate responsibility for project technical quality, schedule, budget, and writing the reports. He will be the primary contact for the project and will coordinate all project activities and ensure that necessary resources are committed to the project. I-Corps Mentor (IM): Dr. Patrick Heist, [email protected] Qualifications: Dr. Heist is well known in the beverage alcohol industry for problem solving skills relative to the microbiology and biochemistry of fermentation. Education includes B.S., M.S., and Ph.D. degrees from the University of Kentucky in Plant Pathology and microbiology-related fields. Dr. Heist spent 6 years as a Medical Microbiology Professor at Kentucky College of Osteopathic Medicine before co-founding Ferm Solutions, Inc., a provider of yeast, fermentation products and technical services to hundreds of distilleries in the U.S. and worldwide. Dr. Heist and his research team collaborate with industrial and academic partners on projects related to controlling bacterial contamination during alcohol production and yeast strain selection and improvement for Bourbon and other distilled spirits and have published multiple times. In 2013, Dr. Heist, along with his business partner Shane Baker, co-founded Wilderness Trail Distillery, which is currently one of the fastest growing premium bourbon whiskey distilleries and in six short years has grown to become the 14th largest Bourbon producer in the U.S. and the 18th member of the Kentucky Bourbon Trail. Brief Description of Technology (Intellectual Merit) This proposal builds on results from an NSF EPSCoR Track 2 project (grant number 1632854: Assembling successful structures: Lignin beads for sustainability of food, energy, and water systems), which developed a novel low cost lignin derived antimicrobial product that has high selectivity in preventing bacterial contaminations in ethanol fermentation. This product has the potential to replace traditional antibiotics commonly used in large scale corn ethanol plants. Lignin, as one of the most abundant natural phenolic polymers on earth, plays an important role in plant defense mechanism, and is currently considered a major waste product in the paper and pulp industries and lignocellulosic biorefineries. Despite the widely reported antioxidant and antimicrobial properties, lignin derived antimicrobials have poor selectivity thus limiting their real-world applications. Our patent-pending synthesis method oxidatively depolymerizes lignin into a liquid product under mild reaction conditions (. 60‹C) using an organic oxidant such as peracetic acid. The resulting product has shown selective antimicrobial properties against the lactic acid bacteria (LABs) by greater than 90% growth reduction, without affecting yeast growth. LABs are common bacterial contaminants in fuel ethanol fermentation that compete nutrients available to yeast for ethanol production. LAB contamination can dramatically reduce ethanol yields and lead to gstuckh fermentations that require costly shutdowns to clean the fermentation vessel and/or associated equipment (pumps, piping, heat exchangers, etc). Our technology offers a potential solution that reduces or eliminates the need for traditional antibiotics by converting a waste stream (lignin) into high value products. Brief Description of Commercial Applications (Broader Impacts) The overuse of antibiotics in agriculture has become an emerging concern to our society, due to the detrimental impact caused by antibiotics to the environment and ecosystems. In the fuel ethanol industry, antibiotics, such as virginiamycin, penicillin, and erythromycin, are introduced prophylactically into the fermentation process to reduce occurrences of bacterial contamination. However, widespread use of such antibiotics increases the chance of antibiotic-resistant bacterial strains that pose an ever-growing risk to human health. Additionally, these antibiotics have been shown to persist in downstream coproducts such as distillersf grains, which is becoming a major concern for consumers of livestock that are fed the distillers grains (stillage) byproduct of fuel ethanol production. The growing demand for biofuels like ethanol also corresponds to a greater demand for contamination control technologies. Therefore, the production of novel antimicrobial agents with similar selective toxicity and better biocompatibility would be highly marketable and useful in the fuel ethanol industry. Our technology offers a solution to this problem by converting a known waste stream (lignin) into a sustainable antibiotic replacement. The research in this I-Corps proposal will study the feasibility of scaling the lignin-derived antimicrobial product into industrial fermentation environments. Once successfully commercialized, the proposed innovation could offer industrial consumers a safer and sustainably-derived antibiotic replacement. The proposed technology uses a low-cost oxidation method at mild reaction conditions that can be retroactively fit into current bleaching processes and equipment. Lignin valorization can be attractive to the paper industry as a strategy to handle the vast volume of lignin waste stream produced every year. The scientific results could be of interest to the National Science Foundationfs goal of researching and promoting new scientific endeavors that are on the cutting edge of science. Brief Description of Current Commercialization Plan The current and future market need for alternative antimicrobials in fuel ethanol industry and other fermentation-based chemical or biofuel production facilities is continually growing. Through this grant, we will explore the commercialization path for our proposed technology, identify market need/niche and consumers, and seek potential commercialization partners. Our current technology has been shown to increase ethanol yields by greater than 8% in a contaminated fermentation when compared to untreated controls in laboratory scale reactors. However, to demonstrate the commercialization potential, additional tests at a demonstration scale reactor will be carried out to guide the technoeconomic analysis to validate the feasibility at industrial/commercial scales. Additionally, we will explore formulation methods (by contacting major agricultural chemical companies) to overcome the hydrophobic nature of the product and improve its solubility and efficiency in commercial-scale fermentation reactors. To enter the current fermentation chemicals market, a product must be differentiated and cost effective to be successful. Since our technology utilizes a plant-derived waste product that is regularly sent to landfills, this suggests that it could become a very competitively priced and attractive product in the current market.