Engineering oleaginous yeast strains in the Yarrowia clade for enhanced growth and lipid production from lignocellulosic biomass

Authors: Quarterman, Joshua; Slininger, Patricia - Pat; Kurtzman, Cletus; Dien, Bruce

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2018
Publication Date: 4/30/2018
Citation: Quarterman, J.C., Slininger, P.J., Kurtzman, C.P., Dien, B.S. 2018. Engineering oleaginous yeast strains in the Yarrowia clade for enhanced growth and lipid production from lignocellulosic biomass[abstract]. Symposium on Biotechnology for Fuels and Chemicals. Paper No. M41: Poster No. PS2.

Interpretive Summary:

Technical Abstract: Oleaginous yeasts have attracted increasing attention for their ability to accumulate intracellular lipids from abundant lignocellulosic biomass feedstocks. However, fermentation inhibitors, generated during conventional biomass pretreatment processes have been observed to inhibit yeast growth. For example, the industrial yeast Yarrowia lipolytica, which is a model species for lipid production, is inhibited by very low concentrations (< 0.5 g/L) of the xylose degradation product furfural. Chemical methods to condition the hydrolysate are expensive. Engineered strains may lower processing costs, but gene targets have not been previously identified to increase inhibitor tolerance in oleaginous yeasts. This work describes engineering and characterization of more robust strains in the Yarrowia clade for lipid and biofuel production from renewable biomass. A strain which produced up to 3-fold higher lipid titers in dilute acid biomass hydrolysate compared to the control Y. lipolytica strain W29 was the starting point. It was engineered for in situ detoxification of inhibitory furan compounds. To this end, several heterologous gene targets were independently expressed under control of the strong Y. lipolytica TEF promoter, and transformants were screened for growth performance in liquid culture with or without a furfural challenge (10 mM). The best recombinant strains showed a significant reduction in lag time and increase in biomass productivity and growth rate (P < 0.01), as compared to the control strain in the presence of furfural. The robust, engineered Yarrowia yeast was further characterized to evaluate other relevant traits, including in vitro enzyme activity and lipid production kinetics in dilute acid-pretreated biomass hydrolysate.