In this study, the effect of pH control and aeration on the production of Aspergillus niger inulinase from sugarbeet molasses in the bioreactor was investigated. The inulinase fermentations were performed at 30 °C temperature in 4°Bx sugarbeet molasses with a 2% (v/v) inoculation rate. The fermentation medium was only supplemented with 4.2% (w/v) yeast extract. In fermentations with aeration (1 vvm), the agitation speed was gradually increased from 200 to 600 rpm. Based on the results, it was determined that the pH-(un)controlled and non-aeration inulinase fermentations caused inadequate fungal growth and thus low inulinase and invertase-type activities, specific inulinase and invertase-type activities, and low maximum production and consumption rates. On the other hand, when the fermentation broth was aerated with 1 vvm, the inulinase and invertase-type activities, specific inulinase and invertase-type activities, and maximum production and consumption rates increased significantly under pH-controlled (5.0) and pH-uncontrolled conditions. In the fermentation with aeration, the highest inulinase and invertase-type activities were yielded as 1825.38 and 1537.88 U/mL under pH-controlled and pH-uncontrolled conditions, respectively. Also, maximum specific inulinase and invertase-type activities and maximum specific inulinase production rate were found as 5361.45 and 4371.58 U/mg and 316.71 U/mL/day with pH-uncontrolled and aerated fermentation. It was found that in both non-aeration and aeration fermentation broths, the pH control had no significant effect on enzyme production (p > 0.05). The inulinase activity/invertase-type activity ratios also varied between 0.95 and 1.56, showing that the enzyme produced is inulinase since the ratios > 10⁻². Besides, with aerated fermentations, excessive and irregular fungal growth was also observed. In conclusion, aeration played a crucial role in increasing the production of inulinase and fungal growth (p < 0.05). Therefore, the best fermentation was performed under pH-uncontrolled and aeration (1 vvm) conditions (200–600 rpm agitation speed, 10 days fermentation duration, 2% (v/v) inoculum level, 30 °C temperature, 4°Bx sugarbeet molasses, and 4.2% (w/v) yeast extract). At these conditions, inulinase and invertase-type activities were 1810.76 and 1537.88 U/mL, respectively.

在这项研究中，pH控制和通气对黑曲霉生产的影响研究了生物反应器中甜菜糖蜜中的菊粉酶。菊粉酶发酵是在30°C的温度下在4°Bx甜菜糖蜜中以2％（v / v）的接种率进行的。发酵培养基仅补充有4.2％（w / v）酵母提取物。在通气发酵（1 vvm）中，搅拌速度从200 rpm逐渐增加。根据这些结果，可以确定，不受pH值控制和无曝气的菊粉酶发酵会导致真菌生长不足，从而导致菊粉酶和转化酶类型的活性降低，菊粉酶和转化酶类型的活性降低，最大产量和消耗量降低费率。另一方面，当用1 vvm充气发酵液时，菊粉酶和转化酶类型的活性，特定的菊粉酶和转化酶类型的活性，在pH值控制为（5.0）和pH值不受控制的条件下，最大产量和消耗率显着增加。在通气发酵中，在pH受控和pH不受控制的条件下，菊粉酶和转化酶型活性最高，分别为1825.38和1537.88 U / mL。同样，在不受pH控制和充气发酵的条件下，发现最大的菊粉酶和转化酶类型活性以及最大的菊粉酶生产速率分别为5361.45和4371.58 U / mg和316.71 U / mL /天。发现在非曝气和曝气发酵肉汤中，pH值控制对酶的产生均无显着影响（在pH受控和pH不受控制的条件下，菊粉酶和转化酶型活性最高，分别为1825.38和1537.88 U / mL。同样，在不受pH控制和充气发酵的条件下，发现最大的菊粉酶和转化酶类型活性以及最大的菊粉酶生产速率分别为5361.45和4371.58 U / mg和316.71 U / mL /天。发现在非曝气和曝气发酵肉汤中，pH值控制对酶的产生均无显着影响（在pH受控和pH不受控制的条件下，菊粉酶和转化酶型活性最高，分别为1825.38和1537.88 U / mL。同样，在不受pH控制和充气发酵的条件下，发现最大的菊粉酶和转化酶类型活性以及最大的菊粉酶生产速率分别为5361.45和4371.58 U / mg和316.71 U / mL /天。发现在非曝气和曝气发酵肉汤中，pH值控制对酶的产生均无显着影响（p > 0.05）。菊粉酶活性/转化酶类型活性之比也在0.95至1.56之间变化，这表明产生的酶是菊粉酶，因为比率> 10 ^-2。此外，在充气发酵条件下，还观察到过量和不规则的真菌生长。总之，通气在增加菊粉酶的产生和真菌生长方面起着至关重要的作用（p <0.05）。因此，最好的发酵是在不受控制的pH和通气（1 vvm）条件下进行的（搅拌速度为200–600 rpm，发酵时间为10天，接种量为2％（v / v），温度为30°C，甜菜为4°Bx）糖蜜和4.2％（w / v）酵母提取物）。在这些条件下，菊粉酶和转化酶的活性分别为1810.76和1537.88 U / mL。