Used for differentiation of Lactobacillus bulgaricus and Streptococcus thermophilus on the basis of colony morphology from yoghurt cultures as per APHA.
HYA Agar is recommended for differentiation of Lactobacillus bulgaricus and Streptococcus thermophilus on the basis of colony morphology. HM peptone B and proteose peptone provides necessary nitrogenous nutrients required for growth of two species. The sugars dextrose, galactose, lactose serve as energy sources. Lactobacillus bulgaricus and Streptococcus thermophilus grows luxuriantlly. L.bulgaricus grow as diffuse, low mass colonies (2-10 mm in diameter) and S.thermophilus as discrete high mass colonies (1-3 mm in diameter).
1.Porubcan R. S., and Sellars R. L., 1973, J. Dairy Sci., 56: 634. 2.Downes F. P. and Ito K., (Eds.), 2001, Compendium of Methods for the Microbiological Examination of Foods, 4th Ed.,APHA, Washington, D.C.