Journal of Industrial Microbiology & Biotechnology

, Volume 38, Issue 9, pp 1345–1357

Phenotypic characterization of Corynebacterium glutamicum under osmotic stress conditions using elementary mode analysis

Original Paper

DOI: 10.1007/s10295-010-0918-z

Cite this article as:
Rajvanshi, M. & Venkatesh, K.V. J Ind Microbiol Biotechnol (2011) 38: 1345. doi:10.1007/s10295-010-0918-z

Abstract

Corynebacterium glutamicum, a soil bacterium, is used to produce amino acids such as lysine and glutamate. C. glutamicum is often exposed to osmolality changes in its medium, and the bacterium has therefore evolved several adaptive response mechanisms to overcome them. In this study we quantify the metabolic response of C. glutamicum under osmotic stress using elementary mode analysis (EMA). Further, we obtain the optimal phenotypic space for the synthesis of lysine and formation of biomass. The analysis demonstrated that with increasing osmotic stress, the flux towards trehalose formation and energy-generating pathways increased, while the flux of anabolic reactions diminished. Nodal analysis indicated that glucose-6-phosphate, phosphoenol pyruvate, and pyruvate nodes were capable of adapting to osmotic stress, whereas the oxaloacetic acid node was relatively unresponsive. Fewer elementary modes were active under stress indicating the rigid behavior of the metabolism in response to high osmolality. Optimal phenotypic space analysis revealed that under normal conditions the organism optimized growth during the initial log phase and lysine and trehalose formation during the stationary phase. However, under osmotic stress, the analysis demonstrated that the organism operates under suboptimal conditions for growth, and lysine and trehalose formation.

Keywords

Corynebacterium glutamicumOsmotic stressElementary mode analysisNodal analysisFlux analysis

Supplementary material

10295_2010_918_MOESM1_ESM.pdf (154 kb)
Supplementary material 1 (PDF 154 kb)

Copyright information

© Society for Industrial Microbiology 2010

Authors and Affiliations

  1. 1.Department of Biosciences and BioengineeringIndian Institute of Technology, BombayMumbaiIndia
  2. 2.Department of Chemical EngineeringIndian Institute of Technology, BombayMumbaiIndia