混合碳源对地衣芽孢杆菌发酵合成杆菌肽的影响

摘要

The effects of batch culture and glucose/lactose fed-batch culture on cell growth and bacitracin production by B.licheniformis were studied in 10 L bioreactor.In the process of batch culture (the control),the maximum biomass and bacitracin production was 91 × 10s CFU/mL at 28 h and 960 U/mL at 32 h,respectively.Glucosefed batch culture from 20 h to 28 h facilitated the second growth,the peak biomass was 115 × 10s CFU/mL at 24 h,which was 26％ higher than that of the control.Nevertheless,the bacitracin synthesis efficiency was 17.2 U/(mL ·h),which was only 53％ of that before glucose feeding.Lactose addition in the production medium enhanced the maximum biomass to 110 × 10s CFU/mL at 32 h,which was 20.6％ higher than that of the control and was nearly the same as that of the glucose-fed batch culture.Meanwhile,bacitracin synthesis efficiency was maintained at 29 U/(mL · h) to 40 h,thus elevating bacitracin production to 1 143 U/mL that was 19％ higher than the control.%在10 L发酵罐水平研究了地衣芽孢杆菌批发酵、补料(葡萄糖、乳糖)批发酵对细胞生长以及溢流代谢和杆菌肽合成的影响.批发酵过程中,细胞28 h达到峰值(91×108 CFU/mL)后自溶,杆菌肽效价32 h达到峰值(960 U/mL)后逐渐降解.20 ～ 28 h流加葡萄糖批发酵的峰值生物量(24 h)为115×1o8 CFU/mL,比对照提高了26％.但是,流加葡萄糖后杆菌肽合成速率(20 ～40 h)是17.2 U/(mL·h),仅为补料前(20 h之前)的53％.基料添加乳糖批培养的峰值生物量(32 h)为110×108 CFU/mL,比分批发酵提高了20.6％,并与流加葡萄糖批发酵接近.同时,杆菌肽以29 U/(mL·h)的速率持续合成至40 h的1 143 U/mL,比分批发酵效价提高了19％.