Note: Determination of Nattokinase Production Condition Using Taguchi Parameter Design

Natto has recently attracted attention throughout the world due to its healthy benefits. In 1987 a potent fibrinolytic enzyme in the extract of natto was discovered and named as ‘nattokinase’. Many biotechnology companies produce nattokinase via the fermentation of Bacillus subtilis natto. Various factors in the fermentation process may affect the production of nattokinase. This work reports the application of Taguchi parameter design to identifying the importance of those factors and then to obtain the optimal condition of fermentation to achieve the maximum yield of enzyme. Seven controllable factors and one noise factor were involved in the experiment. Based on the analysis of experimental data, both the volume of medium and the fermentation time were considered to have a significant effect on nattokinase activity value. Their nominal values should be set as 80mL and 36h, respectively, to maximise the yield of nattokinase.