Which microorganism is responsible for setting curd?

Curd is a dairy product that is formed by the coagulation of milk protein, which is caused by the action of microorganisms. Among the different microorganisms present in curd, the bacterium Lactobacillus is responsible for setting the curd. During fermentation, Lactobacillus produces lactic acid as a by-product, which reacts with the milk protein (casein) to form curd.