Dissolved oxygen level directly affects the synthesis of arginine by Corynebacterium crenatum (C. crenatum). Proteomic approaches including two-dimensional electrophoresis (2-DE) and matrixassisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) were used to analyze differential expression of proteins in C. crenatum in different oxygen supply conditions. The results showed that most of the isoelectric points of the proteins on the 2-DE gels distributed from 4 to 7. Thirtytwo different protein points were detected in the pH 4-7 gels and characterized by MALDI-TOF-MS as well as peptide mass fingerprintings. Using matrixscience database, 29 protein points were identified, and they represented 27 proteins. Database research showed that the proteins performed different functions in carbohydrate metabolism, amino acid metabolism and energy metabolism. Most of the differentially expressed proteins concentrated in the pentose phosphate pathway, TCA cycle and the urea cycle. The results showed that in the high oxygen supply model, energy metabolism was significantly increased, and the oxidative stress was balanced because of the increase of pentose phosphate pathway. Meanwhile, the activation of TCA cycle and urea cycle were beneficial to the synthesis of arginine.%溶氧水平直接影响钝齿棒杆菌合成精氨酸产量的高低,运用双向电泳结合MALDI-TOF-MS及MS/MS质谱鉴定技术的方法对高低供氧条件下高产精氨酸的钝齿棒杆菌的胞内可溶性蛋白进行分离鉴定.结果表明,钝齿棒杆菌菌体蛋白的等电点主要分布在4-7的范围内,采用pH4-7的IPG胶条进行分离,得到了645±12个蛋白点.通过软件比对分析发现,在高低两种供氧条件下存在32个显著差异的蛋白点,成功鉴定出了其中的29个蛋白点,代表了27种差异蛋白.采用数据库检索发现这些蛋白参与不同的代谢途径,包括糖类代谢、氨基酸代谢及能量代谢等.其主要集中在HMP途径、TCA循环和尿素循环.分析结果表明,在高供氧条件下能量代谢水平提高,HMP途径的增强可明显缓解高供氧条件下的氧化压力,同时TCA和尿素循环途径活跃有利于精氨酸的合成.
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