It is also capable of generating energy, in the form of adenosine triphosphate (ATP), by aerobic respiration with the presence of oxygen; however, without the presence of oxygen, it still can produce ATP through fermentation. Optimum growth temperatures for 9 strains of S. thermophilus and 10 strains of L. bulgaricus ranged from 35 to 42°C for S. thermophilus and 43 to 46°C for L. bulgaricus. Streptococcus thermophilus and L. bulgaricus strains exhibiting similar to divergent optimum growth temperatures were combined (1:1 vol.vol) and incubated in milk at 37, 42, and 45°C until pH 4.2 was reached. ... has high temperature and alkaline activity optima and is relatively thermostable [15]. S. thermophilus lacks cyt… Streptococcus thermophilus is a member of the Salivarius group, ... Streptococcus thermophilus is used widely as a starter in the manufacture of a wide range of cheeses and yogurt. Streptococcus thermophilus is an essential lactic acid bacterium used for commercial purposes, which includes the production of milk, cheese, and other dairy products. This organism is a thermophilic Gram-positive bacterium with an optimal growth rate at 45 °C.