E.S.T.Y. MEDIUM 500 grams/bottle

ESTY Medium is a medium recommended for the growth of lactic streptococci and their bacteriophages from yogurt and other dairy products. This medium is recommended for Streptococcus thermophilus isolation and enumeration in yogurt. Lactic streptococci produce acid and are difficult to grow. They are nutritionally fastidious and demand complex culture media for an optimum growth. Glycerophosphate present in high concentrations acts as a pH regulator and inhibits Lactobacillus bulgaricus development while the ascorbic acid promotes the growth of lactic streptococci. It is recommended for the maintenance of the initial cultures, where this microorganisms produce acids in their metabolism. Beef extract, tryptone and soy peptone provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Disodium glycerophosphate is a buffering agent. Ascorbic acid promotes the growth of Lactic Streptococci. Magnesium sulphate provides ions required in a large variation of enzymatic reactions, including DNA replication, and also acts as a buffer. Bacteriological agar is the solidifying agent.