do you want to introduce an adulteration to effect (modify, impair?) the acidification that leads to coagulation in the manufacturing of cultured dairy products? Am i understanding well your question? if that is the case, then antibiotics will impair the process, unless you make a direct acidification with known acids. Or do you want to induce coaguIation via addition of adulterants??? I need to understand your problem to try to provide an answer.