There is many review on the subject either by chemical mutation or by chemical/biological induction.
just do some bibliographic search. Some preliminary info could be found here : https://www.researchgate.net/publication/260996012_Metabolite_induction_via_microorganism_co-culture_A_potential_way_to_enhance_chemical_diversity_for_drug_discovery
If you focus on chemical based mutation look in the references from that review.
Article Metabolite induction via microorganism co-culture: A potenti...