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Title | Improved L-threonine production of Escherichia coli mutant by optimization of culture conditions |
Authors | M-H Lee; Hong-Weon Lee; J-H Park; Jungoh Ahn; Joon-Ki Jung; Y-I Hwang |
Publisher | Elsevier |
Issue Date | 2006 |
Citation | Journal of Bioscience and Bioengineering, vol. 101, no. 2, pp. 127-130 |
Keywords | biotin; escherichia coli MT201; l-methionine; l-threonine; minimal salt medium; cell culture; optimization; salts; synthesis (chemical); escherichia coli |
Abstract | l-Threonine production was investigated in a minimal salt medium using l-threonine-overproducing Escherichia coli MT201, derived from E. coli K-12. It was observed that dry cell weight reached 12.5 g/l with 15.9 g/l l-threonine. To increase dry cell weight and l-threonine production, the fermentation process was optimized. When biotin was added as growth factor, l-threonine production reached 52.0 g/l from 15.9 g/l without biotin. Dry cell weight and l-threonine production were further increased by continuous feeding of the feed media with an optimized l-methionine concentration (5.0 g/l). However, high-cell-density culture caused oxygen-limited condition, which resulted in the accumulation of organic acids. To overcome this problem, oxygen-enriched air was supplied to the fermentor with the minimal salt medium. Under these optimal conditions, we achieved an l-threonine production of 80.2 g/l in the minimal salt medium. |
ISSN | 1389-1723 |
Link | |
Appears in Collections | |
Registered Date |
2017-04-19 |
