Centrifugal partition extraction, a new method for direct metabolites recovery from culture broth: Case study of torularhodin recovery from Rhodotorula rubra

Centrifugal partition extraction (CPE), close to centrifugal partition chromatography, put in contact in a continuous way two immiscible liquid phases. This work presents early experiments on CPE use for solid–liquid–liquid extraction. It was applied to the direct treatment of culture broth for metabolites recovery. Torularhodin is one of the carotenoid pigments produced by the yeast Rhodotorula sp., with a terminal carboxylic group considered nowadays as a powerful antioxidant to be included in food and drugs formulations. Torularhodin was extracted from Rhodotorula rubra ICCF 209 cells by CPE. The recovery of torularhodin reaches 74 μg/g of biomass i.e. 294 μg/L of culture medium. The efficiency of the extraction step increased with the operating flow rate. The extraction yield could reach 91% with a contact time lower than 2 min. A 300 mL apparatus allowed a feed at 90 mL/min. The technique is proposed for extraction or sample preparation before analysis.