Optimized production of PHBV copolymers by mixotrophic fermentation of Cupriavidus necator
摘要
Herein, enhanced PHBV production process by Cupriavidus necator MT-68 was developed through mixotrophic fermentation using low-cost and abundance molasses and various co-substrates. Among nine co-substrates examined, mixture of molasses and propanol provided the best PHBV production performance. By controlling the production of 3HB via feeding of sugars in molasses and 3HV via feeding of propanol in two-stage fed-batch process, the production of PHBV with high 3HV content was obtained and its production efficiency was improved by 2-fold compared to batch process. Under fed-batch cultivation, (2.7 ± 0.2) g/L of PHBV with 3HV molar fractions of 41.9% was achieved. PHBV production, with different 3HV fraction and rearrangement, was also demonstrated through two-stage fed-batch with alternated feeding patterns of molasses and propanol. Overall, this mixotrophic strategy enabled the production of PHBV with a high 3HV content, which could improve bioplastic flexibility and broaden its potential applications.