Question

In the case of temperature change from 25 C to 37 C:

What are the changes in the microorganism regulation system? 
What effects would it have? 
In the case of B.subtulis that represses any sensor? What stimulus response would it have?

Answer 1

Answer :

Q)

The main change happening to regulation of microorganism is lower temperature triggers induction of genes and repression of another few genes as compared to organism in higher temperature.

Example : Bacillus Subtilis triggers induction of 279 genes and repress another 301 genes when climate changes to 25 degree celcius from 37 degree celcius.

Q)

Important transcriptional changes in low temperature grown cells comprise the induction of Sig B controlled general stress regulon. The induction of parts of the early sporulation regulons and the induction of a regulatory circuit. That is involved in the fine tuning of phosphorylation status of the Spo0A response regulator. There is reduction in major anabolic and catabolic routes which causes a low growth rate in lower temperature.

Q)

In Bacillus Subtilis there is repression of 301 genes in response to cold stimuli. This results in repression of major catabolic pathways as glycolysis, oxidative phosphorylation and ATP synthesis. Also anabolic routes as biosynthesis of purines, pyramidines, haem and fatty acids.

Another repression is in part of SigW regulon and with many genes with predicted functions chemotaxis, and motility.

Q)

So they will have lower growth rate compared to existence in higher temperature. Their motility and chemotactic stimulus response will also decrease.