典型性甲基供体对脱氮假单胞杆菌代谢过程的氧调控作用
详细信息Regulatory effect of the typical methyl-group donors on the oxygen metabolism in Pseudomonas denitrificans
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摘要: 本文在7L发酵罐中分别以甜菜碱和氯化胆碱作为合成维生素B12的甲基供体,分别考察了二者对脱氮假单胞杆菌代谢过程的影响。结果表明:使用氯化胆碱的罐批出现了溶氧过早回升、pH剧烈下降等异常的代谢现象,致使发酵过程的菌体生长缓慢且维生素B12合成量低;而使用甜菜碱作为甲基供体时,其菌体代谢活力要明显优于使用氯化胆碱的罐批,整个发酵过程的pH和溶氧均能保持在稳定且合适的水平,最终的菌体量和维生素B12产量也更高。Abstract: In this paper, the fermentation processes of Pseudomonas denitrificans were investigated in 7L fermenter by using betaine and choline chloride as the typical methyl-group donors for vitamin B12 biosynthesis, respectively.When using choline chloride as the methyl-group donor, the dissolved oxygen (DO) and pH respectively presented an obviously zooming and dropping phenomena, resulting in a slow cell growth and low vitamin B12biosynthesis.However, the metabolism capability under betaine as methyl-group donor was significantly better than that of choline chloride, and the pH and DO could be maintained at a stable and appropriate level during the whole fermentation processes.As a result, the final cell growth and vitamin B12 production were significantly higher than those obtained in choline chloride.
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