Engineering the oleaginous yeast Yarrowia lipolytica to produce the aroma compound β-ionone

• DOI: 10.1186/s12934-018-0984-x
• Publication Date: 2018-09-01T06:44:53Z
• Authors: Jeffrey J. Czajka; Justin A. Nathenson; Veronica T. Benites; Edward E. K. Baidoo; Qianshun Cheng; Yechun Wang; Yinjie J. Tang
• Keywords: Yarrowia; Ionone; Aroma compound

β-Ionone is a fragrant terpenoid that generates pleasant floral scent and used in diverse applications as cosmetic flavoring ingredient. A growing consumer desire for natural products has increased the market demand β-ionone. To date, chemical extraction from plants remains main approach commercial β-ionone production. Unfortunately, changing climate geopolitical issues can cause instability supply chain. Microbial fermentation using generally recognized safe (GRAS) yeast offers an alternative method producing Yarrowia lipolytica attractive host due to its oleaginous nature, established genetic tools, large intercellular pool size of acetyl-CoA (the backbone precursor). push–pull strategy via genome engineering was applied Y. PO1f derived strain. Heterologous native genes mevalonate pathway were overexpressed push production geranylgeranyl pyrophosphate, while carB biofunction carRP Mucor circinelloides introduced pull flux towards β-carotene (i.e., ionone Medium tests combined with machine learning based data analysis 13C metabolite labeling investigated influential nutrients strain achieved > 2.5 g/L rich medium. Further introduction carotenoid cleavage dioxygenase 1 (CCD1) Osmanthus fragrans resulted Utilization situ dodecane trapping avoided loss vaporization (with recovery efficiencies ~ 76%) during operations, which titers 68 mg/L shaking flasks 380 2 L fermenter. Both medium outcomes indicated last enzymatic step CCD1 (rather than supply) key bottleneck. We engineered GRAS platform sustainable economical aroma Although could be produced at high by lipolytica, synthesis relatively poor, possibly low activity non-specific β-carotene. In addition, both strains showed decreased performances after successive sub-cultures. For industrial application, efforts should focus on CCD enzyme stability improvement.