Modelling carbon core metabolism in Bacillus subtilis (BaCell-SysMo2)

Modelling carbon core metabolism in Bacillus subtilis (BaCell-SysMo2)

The BaCell project is part of the SysMo transnational network, an initiative focusing on approaches on the application of Systems Biology to microorganisms. In the BaCell project, our interest is to gain a better understanding of the dynamics of the transition from exponential to stationary growth phase in Bacillus subtilis. Obtaining knowledge in this model organism provides twofold advances: First, elucidating the fundamental processes in bacterial growth and stress response. Second, Bacillus subtilis is used in many biotechnological applications, thus our research improves production of medical drugs and consumer goods.

In Rostock, we focus on the sigB-mediated general stress response. SigB is a global transcription factor controlling the expression of about 200 genes involved in stress protection. We developed a model of the sigB-mediated stress response which we improved by using new experimental data from our collaborators of the Völker group in Greifswald. The improved model quantitatively captures the observed behaviour during stress response of Bacillus subtilis.

Based on previous works, we established a model able to reproduce the dynamic, energy-dependent activation of the general stress response.
We predict a mechanism that explains the observed behaviour of mutant strain BSA115 relative to the wild type: Our hypothesis is that the LacZ proteolytic stability has to change during general stress response.

Our finding has impact on interpretation of past and design of future experiments.