Development Of Yeast Strains for Production of Oleochemicals

Globally, more than 350 million metric tons of plastic polymers are produced annually, and their production is anticipated to quadruple by 2050. As much as three quarters of this material is single use, and only a small proportion is currently recycled. In 2018, 36 million tons of plastic waste were generated in the United States and 24 percent of that waste was recycled or incinerated. The remaining material was either sent to landfills or escaped into the environment. The Department of Energy recognizes the significance of this environmental problem and is seeking innovative research to develop a solution. Southeastern Biochemicals recognizes this opportunity to capture plastic waste before it reaches the landfills and the environment and profitably upcycle it into biochemicals. Their approach is to use a fermentation technology in which plastic wastes are heated to convert them into an oil. This oil is then consumed by microorganisms that convert it into biochemicals. Previous work at Southeastern Biochemicals has demonstrated the proof-of-concept of the process to convert polypropylene into biochemicals in Y. lipolytica, however the product yields were lower than necessary for economic viability. The objective of this project is to apply the principles of genome engineering and microbiome science to leverage metabolically engineered organisms to significantly improve the yield of biochemicals in our process. In this project, we will focus on the upcycling of polypropylene, which is the third largest volume of plastic produced today but has one of the lowest recycle rates. We will assess and engineer two oleaginous yeasts, Y. lipolytica and R. toruloides, to produce fatty acids and fatty alcohols, which are ingredients in many consumer products including detergents, surfactants, and paint. Success in this Phase 1 project will help move our process from technical viability to a technically and financially viable process at commercial scale. Phase II will expand the Phase I success to the remaining major types of plastics to enable Southeastern Biochemicals to process a single stream of plastic waste by eliminating significant, and expensive, feedstock presorting requirements. With this accomplished, Phase II will focus on scaling up the process from bench scale to near-commercial scale. A commercial-scale demonstration biochemical refinery will then be designed and constructed to demonstrate technical and financial viability. With these confirmations, high-volume biochemical refineries will be constructed near the sources of the highest concentrations of plastic waste. With the above accomplished, our solution to give plastic waste a second life as biochemicals will be a reality.