Biogenic amines formation in Streptococcus thermophilus isolated from home-made natural yogurt

► Some dairy fermentative isolates microorganisms produce high ammonia and biogenic amines. ► S. thermophilus isolated from home-made natural yogurt produced ammonia in histidine and lysine decarboxylase broth. ► Most of the S. thermophilus isolates have an ability to form biogenic amines, especially histamine and tyramine. ► Selection of proper strains as starter culture is important.