Optimization of fermentation medium of polyhydroxyalkanoate based on non-grain molasses and pilot scale-up
To promote the development of polyhydroxyalkanoates(PHA),promote the standardization,scale and green operation of non-grain molasses fermentation,reduce PHA fermentation cost and improve production capacity,using Halomonos sp.TD01 as fermentation strain,PHA was produced based on the fermentation of non-grain molasses raw materials.The composition of the fermentation medium was optimized by single factor experi-ment and response surface method,the optimal fermentation medium formula was determined,and the pilot scale-up test was verified after adjusting the fed medium.The optimum technological formula was obtained as follows:molasses addition 33.2 g/L,urea 2.5 g/L,and ammonium sulfate 2.2 g/L.Under these optimal conditions,PHA was 3.12 g/L.After further optimization and amplification in a 2 L fermenter,the results showed that the PHA total yield reached 67.36 g/L,which was 142.13%higher than that before optimization.The results were verified by 5 kL pilot fermentation experi-ments,the results showed that the PHA total yield was 51.16 g/L,which was 83.90%higher than that before optimization.