Incredible role of 2 Bacteria in Yogurt production

S. thermophilus is responsible for yogurt acidity. It's one of the bacterium that is responsible for fermentation of milk by transforming lactose found in milk into lactic acid, creating yogurt. It act as the starter of yogurt production because it firstly used oxygen in the milk to produce new compounds creating good environment for another bacterium ( Lactobacillus delbrueckii ) .
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L. delbrueckii start to function after the S. thermophilus formed new compounds. L.delbrueckii function is to catalyse protein in the milk into amino acids providing good environment for S. thermophilus to keep growing and functioning.

After they helped each other to grow and get nutrients. They both ferment the milk by transforming lactose into lactic acid until acidity is sufficient. Once there is sufficient acidity the casein proteins clump together and cause the milk to be thick which is the yogurt texture. Their fermentation is used for conservation since they will inhibit the growth of other bacteria that could lead to spoilage of yogurt.

S. thermophilus is a Gram-positive, non-pathogenic, facultative anaerobic lactic acid bacterium , non-spore-forming, non-motile and spherical shape bacteria of the family streptococcaceae. Lactobacillus delbrueckii are Gram-positive, non-pathogenic, rod-shape facultatively anaerobic, non-motile, and non-spore-forming bacteria of the family Lactobacillaceae

In yogurt industries many sophisticated machines are used in order to perform food science or food technology. during yogurt production, fermentation is done after the pasteurization of milk to kill harmful bacteria that could be present to increase the safety. Pasteurization also plays a role in the distinct texture of yogurt. High temperatures cause whey protein to bind with casein protein that result in the clumping within the milk to form thick texture of yogurt.

Both lactic acid bacteria are likely safe for human consumption but they have some important precaution . Both S. thermophilus and L. delbreuckii is not safe for breast feeding , pregnancy. S. thermophilus they cause infection to people with organ failure and dysfuctional gut barrier. people with histamine should avoid probiotics and fermented foods since it can produce low amount of biogenic amines. L. delbreuckii may cause an infection in people with cirrhosis. L. weakened immune system