Bacteria in milk that produce yogurt and buttermilk?

These two bacteria are responsible for the fermentation of milk into yogurt and buttermilk.

- Lactobacillus bulgaricus is a rod-shaped Gram-positive bacterium that is found in milk and other dairy products. It is responsible for the production of lactic acid, which gives yogurt and buttermilk their characteristic sour taste. Lactic acid also helps to preserve yogurt and buttermilk by inhibiting the growth of harmful bacteria.

- Streptococcus thermophilus is a spherical Gram-positive bacterium that is also found in milk and other dairy products. It works synergistically with Lactobacillus bulgaricus to produce yogurt and buttermilk. Streptococcus thermophilus helps to break down the proteins in milk, which makes the yogurt and buttermilk more digestible. It also produces acetaldehyde, which gives yogurt and buttermilk their characteristic flavor.