Subject: Why are bacteria affected by pH and temperature?

I am interested in gut flora and am trying to find out the reason for 
optimum ph levels and temperatures. I had an idea that temperature 
could affect protein shape, but i wasn't sure if the effect was 
structural or if enzyme activity is interfered with. I have no 
idea how pH levels influence gut bacteria, but i think they
will tolerate a more acidic environment.

I would be very grateful if you could find the time to help me with 
this query as i have looked through many sources of information and
i can't find any detailed scientific answers.

Thank you for your help

Yours faithfully

Miss A Zecharia  

Re: Why are bacteria affected by pH and temperature?