EUBCE 2026 - Silvia DONZELLA - Agri-Food Residues and Waste Cooking Oil as Sustainable Feedstocks for Microbial Carotenoid and Lipid Production

Agri-Food Residues and Waste Cooking Oil as Sustainable Feedstocks for Microbial Carotenoid and Lipid Production

Short Introductive summary

The global carotenoid market — driven by their use as colorants, antioxidants, and vitamin A sources — is expanding alongside the demand for sustainable and eco-friendly production methods. Yeast-based biotechnology offers a promising, circular-economy-compatible approach, especially when using low-cost agro-industrial residues as culture media. In this study, red yeast bioprocesses were developed using soy okara as a substrate. Enzymatic pre-treatment of okara was optimized to create nutrient-balanced media. HPLC screening of Rhodosporidium and Rhodotorula strains revealed natural producers of ß-carotene, as well as the rarer but potent carotenoids torulene and torularhodin. A fermentation process using Rhodotorula paludigena CBS 6565 in a 2L bioreactor achieved 264 mg/L of total carotenoids — mainly ß-carotene (140 mg/L) and torularhodin (72.5 mg/L) — enhanced by adding waste cooking oil and syrup from candied fruit production. The yeast also accumulated lipids up to 56% of its dry weight (18 g/L). Overall, the results demonstrates how agri-food waste can be transformed into valuable resources for sustainable co-production of carotenoids and microbial oils, offering an integr

S. Donzella, Unimi, Milan, ITALY
D. Romano, Unimi, Milan, ITALY
F. Molinari, Unimi, Milan, ITALY
C. Compagno, Unimi, Milan, ITALY