Lactobacillus Delbrueckii Subsp. bulgaricus

Lactobacillus Delbrueckii Subsp. bulgaricus

Lactobacillus delbrueckii subspecies bulgaricus (until 1984 known as Lactobacillus bulgaricus) is one of several bacteria used for the production of yogurt. It is also found in other naturally fermented products. First identified in 1905 by the Bulgarian doctor Stamen Grigorov, the bacterium feeds on lactose to produce lactic acid, which is used to preserve milk.

It is a Gram-positive rod that may appear long and filamentous. It is non-motile and does not form spores. It is regarded as aciduric or acidophilic, since it requires a low pH (around 5.4–4.6) to grow effectively. The bacterium has complex nutritional requirements.