What does the S. thermophilus bacteria in yogurt look like?

Streptococcus thermophilus, the bacteria found in yogurt, is a spherical, Gram-positive bacterium that typically appears as pairs or chains under a microscope. These bacteria are non-motile and lack flagella, giving them a smooth appearance. They are generally small, measuring about 0.6 to 1.0 micrometers in diameter. In yogurt, they contribute to the fermentation process, resulting in the characteristic texture and tangy flavor.