Quantitative proteomic overview on the Corynebacterium glutamicuml-lysine producing strain DM1730

Corynebacterium glutamicum is one of the most important microorganisms because of its ability to produce and secrete glutamate, lysine and other amino acids. To optimize biotechnological amino acid synthesis it is therefore necessary to understand well how metabolic fluxes can be altered by studying the proteins directing these fluxes. In this work we give a comprehensive quantitative outline about the proteomic state of the l-lysine producing mutant strain DM1730 compared to wild type strain ATCC 13032 in the stationary phase of growth. This study comprises 1107 soluble and membrane proteins, of which 908 have been quantified. C. glutamicum DM1730 seems to produce a large amount of lysine even at the expense of various housekeeping functions. Generally, several proteins that are involved in stress response were found to be significantly more abundant, whereas many members of the protein expression machinery are less abundant as well as most proteins involved in cell growth and division and cell envelope synthesis. Extensive l-lysine production causes C. glutamicum to suffer from oxidative stress and iron limitation. Ultimately, a changed lipid composition of C. glutamicum's cell envelope seems to increase its fluidity, which might be related to altered physiology and membrane processes.