(302h) Extraction and Crystallization of Carotenoids Produced from Engineered Yarrowia Lipolitica

Carotenoids constitute a diverse class of naturally occurring compounds responsible for the orange coloration of many fruits and vegetables. Structurally, they can be divided into two major categories: carotenes and xanthophylls. Carotenes, such as lycopene, β-carotene, and α-carotene, are polyunsaturated hydrocarbons devoid of oxygen-containing functional groups. In contrast, xanthophylls, such as astaxanthin, contain additional keto and hydroxyl groups. Collectively referred to as lipochromes, these lipophilic pigments exhibit substantial health-promoting properties. In particular, β-carotene serves as a major dietary source of provitamin A, essential for vision, immune response, and epithelial maintenance.

In this work, we present a systematic workflow for the extraction and crystallization of β-carotene produced by metabolically engineered Yarrowia lipolytica. Multiple cell disruption methods including high-pressure homogenization, bead beating, and ultrasonication were evaluated to identify the most effective extraction strategy. A range of solvent and antisolvent systems were screened with an emphasis on sustainability, aiming to maximize β-carotene stability while achieving high yield and purity. Through the optimized combination of extraction techniques and solvent selection, we achieved >80% extraction efficiency, along with >90% yield and purity of crystalline β-carotene from combined cooling and antisolvent crystallization. This integrated process establishes a scalable and sustainable route for the downstream recovery of carotenoids from yeast cells.