BRC-BIO: Bioconversion of Food Waste with Non-model Organisms

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Each year 2.86 trillion pounds of food is wasted globally. The U.S. alone wastes approximately 200 billion pounds, which accounts for $240 billion in revenue loss, equal to 30-40% of the total food supply. This waste ends up in landfills, contributing to 3.3 gigatons of greenhouse gas emissions. To reduce waste and greenhouse gases, this research proposes the conversion of food waste to 2,3-butanediol and other valuable end-products. Food waste will be collected from Elementary and Middle Schools within the Nashville, TN Metro Public Schools District to evaluate its potential in bioproduct production, while also increasing awareness and participation from young, underrepresented future scientists. Food waste samples collected from schools will be analyzed with regards to nutrient composition, sorting methods, and storage conditions. These results will help determine the best methods for collecting food waste in the future. To carry-out conversion of food waste to valuable compounds, heat-stable bacteria will be added to food waste to take advantage of naturally occurring microbial fermentation. Unique heat-tolerant bacteria can outcompete other contaminant microbes found in food waste when incubation temperatures are increased to approximately 50 °C. In doing so, food waste will not require sterilization, reducing the cost of conversion and the impact on the environment. Overall, this study will address the existing knowledge gap and help to provide an efficient means of converting food waste to bioproducts. The project will also provide educational and research opportunities for undergraduate students.The major goal of this project is to convert non-sterile food waste into valuable bioproducts through “open” thermophilic fermentation. One of the major concerns of using food waste for bioproduct production is the unpredictable heterogeneity and inconsistent nature. While food waste does contain high energy macromolecules for microbial fermentation, a consistent feedstock is needed to sustain a potential bioeconomy through food waste remediation. Another issue limiting the usage of food waste is the cost associated with sterilization. To remove native contaminant microorganisms, sterilization methods (e.g., high-pressure steam) must be carried out. However, to skip these processes and suppress native microbes, a novel high-heat fermentation method with Bacillus licheniformis YNP5-TSU is proposed. In addition to this approach, collections of new thermophilic microorganisms and metagenomic sequencing of hot springs, within Yellowstone National Park, will be conducted to yield novel heat stable enzymes and/or microorganisms that can be used to improve current thermophilic food waste conversion. The effectiveness of this study will impact future endeavors to use food waste as a sustainable feedstock.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.