NH4+对多黏菌素E产生菌Paenibacillus polymyxa SIIA-1408代谢过程的影响

摘要

Objective The effects of NH4+ have on the metabolic process of polymyxin E producing strain Paenibacilluspolymyxa SIIA-1408 was studied.Methods Different concentrations ofNH4+ were added to the initial fermentation medium ofPaenibacillus polymyxa SIIA-1408 and its metabolites and production yields were analyzed.The desired product apart from polymyxin E was isolated and purified to study its chemical structure.The possible metabolic pathway of Paenibacillus polymyxa SIIA-1408 producing phenyllactic acid was determined by adding possible precursor to its original fermentation medium and identifying possible intermediate metabolite.Results When the concentration of NH4+ in initial fermentation medium was low or no NH4+ was added,the main product of Paenibacillus polymyxa SIIA-1408 was (S)-2-hydroxyl-3-phenyl-propionic acid.With the increasing concentrations of NH4+,the main product gradually turned into polymyxin E.Conclusion In certain concentrations,NH4+ can promote the biosynthesis of polymyxin E,and have a negative effect on the transference of phenylalanine to (S)-2-hydroxyl-3-phenyl-propionic acid in Paenibacillus polymyxa SIIA-1408.%目的 研究NH4+对多黏菌素E产生菌Paenibacillus polymyxa SIIA-1408代谢过程的影响 方法 通过向Paenibacillus polymyxa SIIA-1408的初始发酵培养基中添加不同浓度的NH4+,分析其代谢产物及其产量的变化,对于多黏菌素E以外的目标产物进行分离纯化确定其结构,通过前体的添加和中间代谢产物的验证,确定其可能的代谢途径.结果 初始培养基中不添加NH4+或添加低浓度的NH4+主要产物为(S)-2-羟基-3-苯基丙酸,当NH4+的浓度超过一定浓度后主要产物为多黏菌素E.结论 在一定浓度范围内,NH4+促进Paenibacillus polymyxa SIIA-1408生物合成多黏菌素E,抑制其将苯丙氨酸转化(S)-2-羟基-3-苯基丙酸.