For what could be used our experiment?

Changing the pH of bacteria to investigate how they react to this changes can be useful in treatment methods that are being investigated nowadays. What we are going to do is to change the pH of this bacteria (E. coli) and with this, determinate at which point they die by denaturising or dehidrating.
In this way, this could be use by genetic ingeneers. How are going to use genetic ingeneers this? They can use it because if they are able to introduce in the bacteria some genetic information that can harm cells that can be cancer cells or other disease cells, if they rise the acidity or de salinity of the place were the cancer is, they could attack this cells in a pathogenic environment that would be controlled by especialists and when the cancer is removed or controlled, the scientists could set the salinity or acidity levels down and like this, the bacteria would die and couldn't affect the patient.