Extraction and purification of violacein from Yarrowia lipolytica cells using aqueous solutions of surfactants

BACKGROUND The demand for colorants from natural bio‐based sources is increasing. Violacein is a natural purple‐blue hydrophobic pigment with interesting bioactivity whose expression in genetically modified Yarrowia lipolytica production was successfully achieved. RESULTS In this work, several surfactants were tested in the extraction of violacein from Y. lipolytica cells, and the operational conditions were optimized to maximize the extraction yield. After the optimization, the purification of violacein using aqueous biphasic systems (ABS) composed of Tween 20 and cholinium‐based ionic liquids (ILs) was pursued. The ABS were characterized and applied in the separation of violacein from contaminant proteins, reaching a maximum selectivity of 155 with violacein being fully concentrated in the Tween 20‐rich phase, with 80% of the contaminant proteins present in the extract being removed. CONCLUSION This work led to a conceptual downstream process based on a first step of (solid–liquid) extraction and a second step addressing the separation of violacein from contaminant proteins using ABS. © 2019 Society of Chemical Industry