补料分批发酵优化土壤杆菌A02产可得然胶工艺

Optimization of fed-batch fermentation process for curdlan production by Agrobacterium sp. A02

中文关键词:  土壤杆菌  可得然胶  分批补料发酵  发酵工艺

英文关键词:Agrobacterium sp.  curdlan  fed-batch fermentation  fermentation process

中文摘要:

      目的 提升土壤杆菌A02发酵产可得然胶产量, 对其补料分批发酵工艺进行优化。方法 对土壤杆菌在15 L发酵罐中分批发酵过程进行放料后一次补加碳源、放料后连续补加培养基和放料后一次补加培养基3种补料分批发酵工艺, 探究其对可得然胶产量的影响。结果 放料后一次补加碳源效果最差, 连续补加补加培养基补料工艺效果最好。连续补加培养基和一次补加培养基可得然胶产量分别为66.69 g/L和66.51 g/L, 较一次补加碳源可得然胶产量(53.69 g/L)分别提高了23.97%和24.31%; 生产强度均为0.69 g/(L·h), 较一次补加碳源[0.56 g/(L·h)]提高23.2%。连续补加培养基产胶速率为0.11 g/(h·g-cell), 较一次补加碳源和一次补加培养基工艺[0.09 g/(h·g-cell)]提升22.2%。连续补加培养基和一次补加培养基转化率为44.31%、40.67%, 分别是和一次补加碳源培养基(40.59%)的1.1倍和1.0倍。结论 对比3种补料分批发酵工艺, 在发酵中期放料后连续补加培养基的发酵工艺可得然胶产量、生产强度、比产胶速率和转化率最高, 优于其余两种发酵工艺, 为可得然胶工业化生产提供了理论支撑。

英文摘要:

      Objective To improve the production of curdlan by Agrobacterium sp. A02 during fermentation, and optimize the fed-batch fermentation process. Methods The 3 kinds of fed-batch fermentation processes were carried out for Agrobacterium sp. during the batch fermentation process in a 15 L fermenter, including a single supplementation of carbon source after discharging the fermentation broth, continuous feeding of the culture medium after discharging, and a single supplementation of the culture medium after discharging. The effects of these processes on the production of curdlan were investigated. Results The single supplementation of carbon source after discharging had the worst effect, while the continuous feeding of the culture medium had the best effect. The curdlan production obtained by continuous medium supplementation and one-time medium supplementation was 66.69 g/L and 66.51 g/L respectively. Compared with the curdlan production obtained by one-time carbon source supplementation (53.69 g/L), it increased by 23.97% and 24.31% respectively. The production intensity was all 0.69 g/(L·h), which was 23.2% higher than the one-time carbon source supplementation [0.56 g/(L·h)]. The curdlan production rate of continuous medium supplementation was 0.11 g/(h·g-cell), which was 22.2% higher than the process of one-time carbon source supplementation and one-time medium supplementation [0.09 g/(h·g-cell)]. The conversion rates of continuous medium supplementation and one-time medium supplementation were 44.31% and 40.67% respectively, which were 1.1 times and 1.0 times that of one-time carbon source supplementation (40.67%). Conclusion By comparing the 3 kinds of fed-batch fermentation processes, the fermentation process of continuous feeding of the culture medium after discharging in the middle stage of fermentation has the highest production of curdlan, production intensity, specific curdlan production rate and conversion rate, which is superior to the other 2 kinds of fermentation processes. This study provides useful information for enhancing the industrial production of curdlan.