Li W Z, Yang Y X, Yang H F
Wei Sheng Wu Xue Bao. 1989 Apr;29(2):117-23.
It was detected that both NAD(P)H-linked reductase (TNT-Red) and NAD(P)+-linked TNT dehydrogenase (TNT-Deh) were present in TNT-degrading enzymes of Citrobacter freundii simultaneously. The time course of formation for the enzymes and the actions of coenzymes in enzymatic reaction of TNT have been studied. The effects of varied carbon and nitrogen sources on the regulation of the enzymes were different clearly. When the concentration of NH4Cl or urea in culture medium was more than 0.1 mol/L, the formation of both TNT reductase and TNT dehydrogenase was promoted. However, the formation of these enzymes was inhibited by KNO3 in culture. The production of both reductase and dehydrogenase was promoted by glucose. The sodium citrate was able to help the formation of the TNT dehydrogenase. The activity of the TNT reductase was increased when the concentration of sodium citrate was less than 0.5%, but when it was more than 0.5%, the activity of this enzyme was decreased rapidly.
检测发现，弗氏柠檬酸杆菌的TNT降解酶中同时存在NAD(P)H连接的还原酶（TNT-Red）和NAD(P)+连接的TNT脱氢酶（TNT-Deh）。研究了这些酶的形成时间进程以及辅酶在TNT酶促反应中的作用。不同碳源和氮源对这些酶的调节作用明显不同。当培养基中NH4Cl或尿素的浓度超过0.1 mol/L时，TNT还原酶和TNT脱氢酶的形成均得到促进。然而，培养基中的KNO3会抑制这些酶的形成。葡萄糖能促进还原酶和脱氢酶的产生。柠檬酸钠有助于TNT脱氢酶的形成。当柠檬酸钠浓度小于0.5%时，TNT还原酶的活性增加，但当浓度超过0.5%时，该酶的活性迅速下降。
