A novel impeller configuration to improve fungal physiology performance and energy conservation for cephalosporin C production

Effects of impeller configuration on fungal physiology and cephalosporin C production were investigated by an industrial strain Acremonium chrysogenum in a 12m(3) bioreactor equipped with conventional and novel impeller configuration, respectively. The cell growth and oxygen uptake rate (OUR) profiles were little affected by the impeller configurations. However, differing impeller combinations significantly affected the morphology, which in turn influenced cephalosporin C production. Under the novel impeller configuration, the production of cephalosporin C was 10% higher and an excessive amount of dispersed arthrospores was also observed. Computational fluid dynamics (CFD) simulation further revealed that poor mass and energy exchange as well as inhomogeneous environment existed in the bioreactor equipped with conventional impeller configuration. For equivalent power dissipation, the volume oxygen transfer coefficient (K(L)a) could be enhanced by 15% compared with that of conventional impeller configuration. Power consumption was dramatically decreased by 25% by using novel impeller configuration.