不同碳源对E.adhaerens产维生素B12发酵代谢动力学分析OA北大核心CHSSCD

Vitamin B12(VB12)has a variety of physiological functions and is widely used in the pharmaceutical and food industries.During the industrial process of Ensifer Adhaerens(E.adhaerens)fermentation to produce VB12,the type of carbon source has a significant influence on the anabolism of E.adhaerens.In this paper,we investigated the physiological metabolic properties of the E.adhaerens under different carbon sources conditions(maltose,sucrose,glucose and fructose),and used Logistic and Luedeking-Piret models to deeply analyze the changes in growth kinetics and product synthesis kinetic properties during the fermentation of E.adhaerens.The results showed that sucrose could significantly promote the growth and anabolism of E.adhaerens,and the fermentation units were 53%,40%and 103%higher than those of the glucose,maltose and fructose groups under the supplemented batch culture conditions,respectively.Fermentation kinetic analysis showed that the fitted kinetic parameters α and β values were not zero under different carbon source conditions,and the production of VB12 by E.adhaerens showed a partial growth-associated type.Among them,sucrose was the optimal carbon source with the maximum specific growth rate and maximum units of 0.054 h-1 and 115 mg/L,respectively.During the fermentation process of E.adhaerens,sucrose could be gradually decomposed into glucose and fructose to maintain an appropriate glucose production rate,which is used to provide sufficient energy and precursors for bacterial growth and VB12 synthesis,effectively alleviating the inhibition of bacterial growth and product synthesis by high glucose concentration.