| The fermentation conditions for sporulation quantity by Trichoderma viride strain H06 was optimized by response surface methodology (RSM) based on single factor tests. Firstly, three of the most significant influence factors were
screened by the method of Plackett-Burman design as loading volume of liquid medium, inoculum volume and temperature.
The path of steepest ascent was applied to approach the optimal region of the three significant factors. Lastly, the optimal concentration and correlations among three factors were identified by RSM. The optimal fermentation conditions were determined as followed: rotate 200 r/min，loading volume of liquid medium 74.70 mL/250mL，inoculum volume 5.83%，pH
7.5，temperature 29.50℃，time 72 h，bacterium age 48 h. Under these conditions，the maximum theoretic spore number was
7.64*1000000000 mL-1. After three parallel verifications，the maximum theoretic value was consistent with mean value of verification test and the spore number increased by 133% compared to that before optimization. |
