Clarification on the usage of Rennet

Assalam Alyaikum Ua Rakhmattullakhi Ua Barokyatukh! I read in your fatwa that cheese is not permissible in basic as meat. How I know the bacteria starter in cheese and other milk products usually grown on milk even the teachers on “cheese making” say so. Maybe in rare cases they are grown on other nutrient medium (I don’t know which ones exactly but from microbial technology everything can be) I read in somewhere that they can be grown on whey but I don’t can it be really in milk products production.

Can I eat milk products with bacteria starter? Even there is possibility that nutrient medium can be another one than milk there is a rule that everything is halal in basic except meat. If people don’t eat milk products will be great problems for health. We havent normal halal certification on our countries to eat only checked products.