Engineering novel Yarrowia lipolytica whole-cell biocatalysts by cell surface display of the native Lip2 lipase for biodiesel production

Yeast surface display (YSD) has proven to be a valuable tool in cellular engineering, particularly for conferring biocatalytic activities to cells, thereby enabling the creation of novel whole-cell biocatalysts. Compared to intracellular and secretion-based strategies, cell surface display of enzymes offers distinct advantages, including the elimination of enzyme recovery and purification steps, the resolution of substrate transport limitations, and enhanced activity, stability, and selectivity. In this work, YSD was employed to construct efficient display systems for Yarrowia lipolytica using the native lipase Lip2 fused with constitutive promoter-based anchoring vectors. The biocatalytic activity of the Lip2 biomass–bound recombinant strains was evaluated in transesterification reaction (butanolysis of p-nitrophenyl palmitate). The best-performing strain expressing the LIP2 gene under the UAS1B8-TMAL(250) hybrid promoter was cultivated in a lab-scale bioreactor to identify crucial parameters that have to be fine-tuned for a scalable bioprocess that yields biomass of both high density and Lip2 activity. Harvested biomass was used to catalyze the synthesis of biodiesel (olive oil methanolysis) yielding under optimal reaction conditions 71.4% conversion after 48 h.