Studies on substrate utilisation in l-valine-producing Corynebacterium glutamicum strains deficient in pyruvate dehydrogenase complex |
| |
Authors: | Tobias Bartek Christiane Rudolf Ulrike Kerßen Bianca Klein Bastian Blombach Siegmund Lang Bernhard J Eikmanns Marco Oldiges |
| |
Institution: | 1. Institute of Biotechnology 2, Forschungszentrum Jülich, 52425, Jülich, Germany 4. Lonza Biopharmaceuticals, R&D Microbial Services, Lonza AG, 3930, Visp, Switzerland 2. Institute of Microbiology and Biotechnology, University of Ulm, 89069, Ulm, Germany 3. Institute for Biochemistry and Biotechnology, Braunschweig University of Technology, 38106, Braunschweig, Germany
|
| |
Abstract: | The pyruvate dehydrogenase complex was deleted to increase precursor availability in Corynebacterium glutamicum strains overproducing l-valine. The resulting auxotrophy is treated by adding acetate in addition glucose for growth, resulting in the puzzling fact
of gluconeogenic growth with strongly reduced glucose uptake in the presence of acetate in the medium. This result was proven
by intracellular metabolite analysis and labelling experiments. To increase productivity, the SugR protein involved in negative
regulation of the phosphotransferase system, was inactivated, resulting in enhanced consumption of glucose. However, the surplus
in substrate uptake was not converted to l-valine; instead, the formation of up to 289 μM xylulose was observed for the first time in C. glutamicum. As an alternative to the genetic engineering solution, a straightforward process engineering approach is proposed. Acetate
limitation resulted in a more efficient use of acetate as cosubstrate, shown by an increased biomass yield Y
X/Ac and improved l-valine formation. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|