Which among the following microbe is used in the production of curd from milk ?

Lactobacillus.

Among the options provided, Lactobacillus is the microbe used in the production of curd from milk. Lactobacillus species, particularly Lactobacillus bulgaricus and Streptococcus thermophilus, are commonly used as starter cultures in the production of curd or yogurt. These bacteria ferment lactose, the sugar present in milk, and convert it into lactic acid. The lactic acid lowers the pH of the milk, causing it to coagulate and form curd. This process of bacterial fermentation by Lactobacillus helps in the transformation of milk into curd, giving it its characteristic texture and tangy flavor.

In contrast, Saccharomyces cerevisiae is a yeast commonly used in bread-making and fermentation of alcoholic beverages, while Propionibacterium sharmanii is involved in the production of Swiss cheese and is not typically used in curd production.