Hirasawa Takashi, Kim Jongpill, Shirai Tomokazu, Furusawa Chikara, Shimizu Hiroshi
Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Subcell Biochem. 2012;64:261-81. doi: 10.1007/978-94-007-5055-5_13.
Glutamate is a commercially important chemical. It is used as a flavor enhancer and is a major raw material for producing industrially useful chemicals. A coryneform bacterium, Corynebacterium glutamicum, was isolated in 1956 by Japanese researchers as a glutamate-overproducing bacterium and since then, remarkable progress in glutamate production has been made using this microorganism. Currently, the global market for glutamate is over 2.5 million tons per year. Glutamate overproduction by C. glutamicum is induced by specific treatments-biotin limitation, addition of fatty acid ester surfactants such as Tween 40, and addition of β-lactam antibiotics such as penicillin. Molecular biology and metabolic engineering studies on glutamate overproduction have revealed that metabolic flow is significantly altered by these treatments. These studies have also provided insight into the molecular mechanisms underlying these changes. In this chapter, we review our current understanding of the molecular mechanisms of glutamate overproduction in C. glutamicum, and we discuss the advances made by metabolic engineering of this microorganism.
谷氨酸是一种具有重要商业价值的化学物质。它被用作增味剂，并且是生产工业用化学品的主要原料。1956年，日本研究人员分离出一种棒状杆菌——谷氨酸棒杆菌，作为一种谷氨酸高产细菌，从那时起，利用这种微生物在谷氨酸生产方面取得了显著进展。目前，全球谷氨酸市场每年超过250万吨。谷氨酸棒杆菌过量生产谷氨酸是由特定处理诱导的——生物素限制、添加脂肪酸酯表面活性剂（如吐温40）以及添加β-内酰胺抗生素（如青霉素）。关于谷氨酸过量生产的分子生物学和代谢工程研究表明，这些处理会显著改变代谢流。这些研究还深入了解了这些变化背后的分子机制。在本章中，我们回顾了目前对谷氨酸棒杆菌中谷氨酸过量生产分子机制的理解，并讨论了该微生物代谢工程所取得的进展。
