At a glance
Essentials
- Habitat
- It is found in milk and fermented dairy products.
- Activity
- It participates as a starter culture in yogurt fermentation, often along with Lactobacillus delbrueckii subsp. bulgaricus.
Observation guide
What to look for
- 01
It is a Gram-positive bacterium with spherical cells; it exhibits no motility and does not form spores.
- 02
Its metabolism is described as fermentative and facultatively anaerobic.
Lighting, age and viewing angle can hide features. If identification affects consumption, handling or conservation, consult specialist sources.
Ecology
Description and characteristics
Streptococcus thermophilus is a lactic acid bacterium that is Gram-positive and facultatively anaerobic. Its cells are spherical, non-motile, and do not form spores. It is found in fermented dairy products and participates, along with Lactobacillus delbrueckii subsp. bulgaricus, in the fermentation that produces yogurt. During this association, the metabolism of both bacteria can favor the growth of the other; it is described that S. thermophilus provides formic acid, while L. delbrueckii subsp. bulgaricus produces small peptides and amino acids that favor the growth of S. thermophilus.