Hydrolysis of fruit and vegetable waste for efficient succinic acid production with engineered Yarrowia lipolytica

Abstract

Abstract Bio-based production of succinic acid (SA) is regarded to supplement the petro-based processing for environmental reasons. However, in order to enhance the industrial competitiveness of bio-based SA, it is necessary to develop a method that is cost-effective, environmental friendly and with high efficiency. In this study, the utilization of fruit and vegetable waste (FVW) hydrolysate for SA production via engineered Yarrowia lipolytica was reported for the first time. In the study, the hydrolysis conditions were firstly optimized and the final glucose concentration of 56.7 g L−1 and a yield of 0.46 g g−1 were obtained with 2% glucoamylase, 1% cellulase, 2% hemicellulase and 0.25% pectinase at pH 5.0 and 55 °C. Then, the feasibility of using the hydrolysate for SA production via Y. lipolytica PSA02004 was demonstrated. SA titer and yield at 43.1 g L−1 and 0.46 g g−1, respectively were obtained using 100 g L−1 glucose-containing FVW hydrolysate and 4% corn steep liquor (CSL) as fermentation medium by free cell batch fermentation. Finally, in situ fibrous bed bioreactor (isFBB) and fed batch fermentation were demonstrated to be effective approach for improved SA production, from which SA productivity of 0.69 g L−1 h−1 and the resultant SA concentration of 140.6 g L−1 were achieved, respectively. In summary, this study achieved the anticipated target of turning waste into value-added products with high efficiency and cost-effectiveness.