Supercritical Fluid Extraction of Avermectin from Streptomyces avermitilis Using Carbon Dioxide

The process of supercritical fluid extraction (SCFE) of avermectin from the bacterial biomass of Streptomyces avermitilis with carbon dioxide is optimized by the method of a full factorial experiment using a second-order rotatable uniform plan. In the planning, the main levels chosen are a pressure of 25 MPa, a temperature of 60°C, and an extraction duration of 100 min. The analysis of the regression equation makes it possible to establish the optimal process parameters: 30 MPa, 85°C, and 133 min. In the control experiment, an extract is obtained with a yield of 13%, containing 41% avermectin. The yield of avermectin of an absolutely dry (a.d.) biomass is 5.36%, which exceeds the extraction yields obtained using organic solvents.