Engineering Yarrowia lipolytica for de novo production of tetraacetyl phytosphingosine.

Abstract

To genetically engineer the oleaginous yeast Yarrowia lipolytica for de novo production of tetraacetylphytosphingosine (TAPS), a precursor of phytosphingosine, and optimization of fermentation conditions for high yield. We successfully constructed a TAPS-producing Y. lipolytica CE3 strain by co-expression of Wickerhamomyces ciferrii-derived acetyl transferases, Sli1p and Atf2p. Next, we optimized several environmental factors including temperature, initial pH and C/N ratio for TAPS production in a shake culture. Deletion of LCB4 in CE3 strain increased the volumetric TAPS titre and cell-specific yield to 142·1±10·7mgTAPS l-1 and 3·08±0·11mgTAPS gDCW -1 , respectively, in a shake flask culture incubated for 120h at 28°C with glycerol as the carbon source. Finally, we developed a 5-l fed-batch process with NaOH-mediated pH control and olive oil as a carbon source, exhibiting 650±24mgTAPS l-1 of TAPS production within 56h of the fermentation. The introduction of codon-optimized Sli1p and Atf2p, deletion of LCB4 gene and sexual hybridization, accompanied by specific fermentation conditions, enhanced TAPS yield in Y. lipolytica. Our results highlight Y. lipolytica as a promising candidate for the industrial production of TAPS, an important component of cosmetic formulations.