Starter culture microbes in fermentation typically include bacteria that produce lactic acid, such as which genus?

• A. Escherichia coli
• B. Lactic acid bacteria (e.g., Lactobacillus spp.)
• C. Clostridium spp.
• D. Staphylococcus aureus

Answer: (B)

In fermentation, starter cultures are chosen for their ability to produce lactic acid, which lowers pH, helps preserve the product, and develops characteristic tangy flavors. Lactic acid bacteria, especially Lactobacillus species, are classic examples of these producers. They metabolize sugars primarily into lactic acid, thrive in the low-oxygen conditions of many fermentations, and are widely used in foods like yogurt, sauerkraut, pickles, and sourdough. That makes the option identifying lactic acid bacteria the best fit. The other bacteria listed don’t serve this role: Escherichia coli is a gut-associated organism not used as a safe food starter; Clostridium species can produce unwanted gases or toxins; Staphylococcus aureus is a potential pathogen and not used as a starter culture in foods.