1前言微生物培养中氮源除作为构成菌体细胞的物质外,对次级代谢产物的合成还具有调控作用。通常,微生物培养所用的氮源为复合氮源,而复合氮源主要由各种氨基酸、多肽和蛋白质组成,且蛋白质和多肽在培养过程中被胞外蛋白酶降解为氨基酸或进一步被降解为铵离子和有机酸才被微生物 1 Introduction Microbial culture in addition to the nitrogen source as the cells that constitute cells, the synthesis of secondary metabolites also play a regulatory role. In general, the nitrogen source used for microbial cultivation is a complex nitrogen source, while the complex nitrogen source is mainly composed of various amino acids, polypeptides and proteins, and the proteins and polypeptides are degraded by the extracellular protease into amino acids or further degraded into ammonium ions And organic acids were microbes