Effect of carbon source availability and growth phase on expression of Corynebacterium glutamicum genes involved in the tricarboxylic acid cycle and glyoxylate bypass
Effect of carbon source availability and growth phase on expression of Corynebacterium glutamicum genes involved in the tricarboxylic acid cycle and glyoxylate bypass
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DOI：
10.1099/mic.0.2008/019828-0
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发表时间：
2008-10-01
期刊：
影响因子：
2.8
通讯作者：
Yukawa, Hideaki
中科院分区：
文献类型：
--
作者：
Han, Sung Ok;Inui, Masayuki;Yukawa, Hideaki
测定了不同碳源对谷氨酸棒杆菌中三羧酸（TCA）循环基因沿着乙醛酸旁路基因表达的影响。所有TCA循环基因在含乙酸的培养基中协调表达。乙酸盐存在下的生长引起大多数TCA循环基因的丰富表达，其中gltA转录物的水平最高。然而，当细胞进入由乙酸耗尽引发的稳定期时，所有基因都被抑制，除了sucCD和mdhB，它们被轻微诱导。乙酸撤出生长培养基中的指数期也导致快速阻遏大多数TCA循环基因和相应的sucCD的表达，这是强烈诱导柠檬酸盐和琥珀酸盐的两倍增加。此外，在稳定期期间葡萄糖消耗导致sucCD、aceA和aceB基因的相应8-20倍诱导。向乙酸盐培养基中加入葡萄糖导致sucCD的诱导增加约10倍。TCA循环sucCD和乙醛酸旁路aceA和aceB表达对碳源可用性的强烈依赖性得到证实，并且将精确地研究调节系统。
The effect of different carbon sources on the expression of tricarboxylic acid (TCA) cycle genes, along with glyoxylate bypass genes, in Corynebacterium glutamicum was determined. All TCA cycle genes were coordinately expressed in medium containing acetate. Growth in the presence of acetate gave rise to abundant expression of most TCA cycle genes, with the level of gltA transcript being the highest. However, when the cells entered the stationary phase triggered by acetate exhaustion, all genes were repressed, except sucCD and mdhB, which were slightly induced. Acetate withdrawal from the growth medium during the exponential phase also led to rapid repression of most TCA cycle genes and a corresponding twofold increase in the expression of sucCD, which were strongly induced by citrate and succinate. In addition, glucose depletion during the stationary phase led to a corresponding 8-20-fold induction of the sucCD, aceA and aceB genes. Addition of glucose to acetate medium resulted in about 10-fold induction of sucCD. The strong dependence of TCA cycle sucCD and glyoxylate bypass aceA and aceB expression on carbon source availability was confirmed and the regulatory system will be studied precisely.