[Optimization of fermentation conditions for the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with...

A close relationship, between the initial addition time and concentration of propionate and HV fraction, was observed in shaking culture of Alcaligenes eutrophus for the production of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate). The optimal initial addition time of propionate was determined at the onset of PHBV formation period. Although relatively high HV unit could be obtained under high propionate concentration, the growth and product synthetic activities were inhibited obviously. Different ratios of glucose to propionate were fed to stimulate the formation of HV unit and the results were compared. The optimizing feeding strategy of propionate was proposed based on the consideration of several fermentation index. The final cell dry weight, PHB concentration, PHB content and HV fraction in PHBV reached 52.1 g/L, 40.8 g/L, 78.3% and 16.2 mol%, respectively, Yield coefficient of HV unit to propionate and PHBV productivity were obtained to be 0.5 g/g and 0.74 g/(L/h), respectively.