So from my understanding, bacteria is competing to reproduce the fastest, and the chemical that we want is simply a byproduct of its metabolism or pathway for

So from my understanding, bacteria is competing to reproduce the fastest, and the chemical that we want is simply a byproduct of its metabolism or pathway for reproduction issue is, however, the byproduct has to either be the most efficient factor for reproduction, or else by natural selection it will be removed my question is, can we use the same techniques found in tree grafting to prevent or delay natural selection, and grow our byproduct?