杆菌肽生产菌种选育及发酵新工艺研究

杆菌肽是一种重要的饲料添加剂,开展菌种选育和发酵工艺研究提高杆菌肽产量十分必要。使用紫外线诱变技术选育淀粉酶分泌能力增强菌种,以加快杆菌肽积累速率。通过静态吸附和解吸实验筛选吸附杆菌肽的树脂。借助发酵吸附分离耦合试验以解除产物反馈抑制,并考察树脂加入时间对杆菌肽产量的影响。选育得到的菌株Bacillus licheniformis Y8226A发酵周期明显缩短。借助发酵吸附分离耦合策略,发酵开始30 h后在50 m L发酵液加入D152树脂1.0 g,最终杆菌肽产量与对照组相比提高了27.40%。通过紫外线诱变选育得到杆菌肽高效生产菌种,使用D152树脂开展发酵吸附分离耦合试验可显著提高杆菌肽产量。

Breeding of bacitracin producing strain and new fermentation technology study

Objective] Bacitracin is a kind of important microbial feed additive. It is necessary to screen strains and optimize fermentation process for improving bacitracin production. Methods] To improve fermentation efficiency of bacitracin, ultraviolet was employed to screen high amylase-secreting strain. Several resins were tested for their static adsorption/desorption performance towards bacitracin. The technology of fermentation coupled with resin adsorption separation was carried out to relieve feedback inhibition and increase bacitracin production. The effect of resin addition time on bacitracin was investigated. Results] Result showed that the fermentation time of obtained mutant strain Bacillus licheniformis Y8226A was shorten obviously. When D152 resin 1.0 g was added to the fermentation broth 50 mL and addition time 30 h, the technology of fermentation coupled with resin adsorption separation has increased the titer of bacitracin by 27.40% in contrast with the group without addition the resin. Conclusion] An efficient bacitracin producing strain was obtained through ultraviolet mutagenesis. Using D152 resin, the titer of bacitracin could be significantly improved by the technology of fermentation coupled with resin adsorption separation.