A novel stirrer design and its application in submerged fermentation of the edible fungus Pleurotus ostreatus

摘要

In this study, a straight diagonal-pitched blade stirrer was designed, built and characterized in a 5-L fer-menter. Compared with the six straight blade Rushton turbine, the power consumption of the new stirrer is lower at a given speed under conditions of no ventilation. The oxygen transference is poorer at the same agitation speed in the cultivation conditions and scales investigated, which confirms that the shear stress of the new stirrer is lower and the gas dispersion is weaker. The new stirrer was installed in a 5-L bioreactor and evaluated in submerged fermentation of the edible fungus Pleurotus ostreatus. The results showed that the maximum dry weight of mycelium is increased by 47 % and reached 7.47 g/L, and the maximum laccase activity is increased by 15 % up to 2,277 U/ L. Glucose consumption was also found to be relatively faster. The power consumption is 2.8 % lower than that of the Rushton turbine.