Production and Extraction of High-Value Wax Esters and Lipids from Yarrowia lipolytica using Cavitation Enhanced Hot Water Extraction.

Biomanufacturing is a sustainable approach to replace Petro-chemical manufacturing for producing fuels, chemicals, materials, and pharmaceuticals. Yeasts, such as Saccharomyces cerevisiae and Yarrowia lipolytica, have been engineered to produce many important high value bioproducts at high titers, rates, and yields (TRYs) for many applications. For example, the nonconventional yeast Y. lipolytica has recently been engineered in Xie lab at UMass Lowell to produce long-chain wax esters (C32-C38) up to 56% of the yeast biomass, which can be used as high-performance biolubricants. However, these compounds are produced as intracellular products in the yeast biomass. Extraction from yeast is notoriously difficult due to the thick and tough cellular walls, and typically involves mechanical cell disruption and solvent extraction processes that significantly increase costs. An inexpensive and efficient cell disruption and product recovery method will make yeast a more attractive microbe for more cost-competitive biomanufacturing. In this proposed Phase I STTR project, we will investigate the feasibility of using hydrodynamic cavitation and hot water to produce transient high temperatures and pressures that will reduce the permittivity of water at lower ambient temperatures and increase mass transfer rates with better mixing to recovery the intracellular yeast products. The proposed process will use less energy, lower temperatures (60 °C - 150°C) and pressures (<50 psi) and require a smaller footprint. The technology can also be applied to other similar intracellular products from yeast. In Phase I, Hydrodynamic cavitation in hot water will be used to extract long-chain (C32-C38) wax esters and lipids from the Yarrowia lipolytica biomass generated by the UMass Lowell team. The reactor and process design will be modelled with numerical simulations of cavitation in the concentrated yeast. Then lab-scale experiments will be used to investigate the performance of the system with respect to the efficiency of the extraction of the yeast. The effects of temperature, cavitation conditions, and extraction time will be determined. Combined lysis and solvent extraction will be examined. The resulting product samples and accumulated technical data will be used for further techno- economic analysis and scale-up studies. This project will result in a method for production of wax esters as biolubricants, which are sourced from sperm whales, Jojoba seeds, and petroleum, as well as lipids for biodiesel production. Biolubricants have a market size > $2 billion. A method for efficient cell disruption and product recovery from yeast and other microbial biomass will have wide application in biotechnology industry.