Ok. thanks for your answers so far. this is what I am suppose to explain more detailed:
Genetics metabolism and nutrition in microbes are very close related together in a dependent relationship that if you alter one of these processes, you will affect the other ones, you will end up altering them as well. If we altering the nutrients that microbes have access to, you will alter the gene expression that it can do, and then the whole metabolism will go through. And if we alter the metabolism, we may alter the DNA, and this will alter the type of nutrients the bacteria will take in.