发酵体系中氨态氮含量的测定及影响因素的探讨

靛酚蓝-分光光度法是一种灵敏度高、设备要求简单、线性相关性好、重现性高的氨态氮检测方法。本文对该方法的检测波长,反应温度、时间以及催化剂浓度等条件进行了优化,确定了最佳的检测波长为637nm,最佳的反应条件为37℃、25 mg.L-1的催化剂和20 m in的反应时间。并由此得到一条线性相关系数为0.9996的氨态氮检测标准曲线。同时,对靛酚蓝法测定氨态氮用于普通发酵体系进行了探讨。对常用发酵基质如炭源、氮源、金属离子以及消泡剂等进行了考察,结果发现这些常用基质基本不影响本法用于氨态氮的测定。最后,将这种氨氮测定方法用于泰乐菌素和阿维菌素的发酵实践,取得了良好效果,由此证明该方法是一种切实可行的发酵中氨态氮的检测方法。

Determination of NH4+ - N in Microbial Fermentation and Some In fluential Factors

NH_4~+-N is a very important factor on the production of metabolites by fermentation process especially on many types of secondary metabolites.Indophenol blue method has been proved high performance,high sensitivity and high reproducibility on NH_4~+-N determination.Detection wavelength,reaction temperature,time and concentration of catalyst have been firstly studied.The best conditions of 37℃ reaction temperature,20min reaction time,25mg·L~(-1) catalyst and 637nm wavelength have been gained after optimization.Many factors about fermentation substrates such as glucose,corn steep liquor,Ca~(2+),antifoam and so on have been studied by indophenol blue method.And the result indicated that normal substrate of the fermentation had no influence on NH_4~+-N determination.