Environmental Stress Response of Corynebacterium glutamicum
Susanne Morbach and Reinhard Krämer
from: Corynebacteria: Genomics and Molecular Biology (Edited by: Andreas Burkovski). Caister Academic Press, U.K. (2008)
Bacteria, like Corynebacterium glutamicum, are confronted with numerous stress situations. These can be caused by two principally different conditions, namely (i) by limitations in the supply of various nutrients, or (ii) by influences from the environment such as variations in temperature, osmolality, pH, and oxygen content, as well as increased heavy metal concentrations. In this chapter we will not describe adaptation processes related to nutrient limitation because this type of stress will be described elsewhere in this issue. Instead we will focus on external stress factors. So far only data are available dealing with the response of C. glutamicum to influences of osmotic, heat and chill stress. These changes are often accompanied by the formation of reactive oxygen species, thus leading also to oxidative stress. In order to adapt to these unfavourable conditions, C. glutamicum has developed several adaptation strategies, which are acting at different levels of the regulatory network as for example by the transcriptional response of a whole sigma factor-dependent regulon or directly at the level of activity of an enzyme or a carrier. In this review we will summarize the knowledge about adaptation strategies of C. glutamicum to heat, oxidative, osmotic, and chill stress read more ...