Introduction. Streptococcus thermophilus belongs to the thermophilic group of lactic acid bacteria. It is traditionally used in association with one or several Lactobacillus species as a starter culture in the production of yogurt and the manufacture of Swiss and Italian cheeses such as Emmentaler and Mozzarella.n common with other lactic acid bacteria, some strains of S. thermophilus produce exocellular polysaccharides (EPS). The EPS produced by S. thermophilus is critically important for the final texture in most yogurt processes.