SM Agar

SM Agar is used for cultivation and enumeration of microorganisms encountered in dairy industry. It is used for the demonstration of coagulation and proteolysis of casein. It is also recommended by APHA for same purpose.Proteolytic bacteria hydrolyze casein to form soluble nitrogenous compounds indicated as clear zone surrounding the colonies. More clear zones are seen on milk agar if, the bacteria produce acid from fermentable carbohydrates in the medium. Pseudomonas aeruginosa, Serratia marcescens, Bacillus subtilis are few known organisms having proteoltic activity.