Streptococcus thermophilus is an essential lactic acid bacterium used for commercial purposes, which include 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. 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. Streptococcus thermophiles lack cytochrome, oxidase, and catalase enzymes. It does not have motility and it does not form spores. Although Streptococcus thermophilous is closely related to other pathogenic streptococci, Streptococcus thermophilous is classified as a non-pathogenic, alpha-hemolytic species that is part of the viridians group. The increasing consumer need for dairy products and the booming manufacture of dairy products ($40 billion industry) led to the investigation and sequencing of Streptococcus thermophilus.