Which of the following is NOT a sugar that Lacto consumes?

Lactobacillus, a prominent genus of lactic acid bacteria, primarily ferments sugars to produce lactic acid. They can utilize a variety of carbohydrates, but they have specific preferences regarding sugar types that they can ferment.

Glucose, fructose, and maltose can all be fermented by Lactobacillus species. Glucose is a primary energy source for many microorganisms due to its simplicity and high fermentability. Fructose, naturally found in fruits, is also easily consumed by Lactobacillus, and maltose, a disaccharide composed of two glucose molecules, is effectively utilized during fermentation processes, particularly in malty beverages.

Galactose, however, is less commonly consumed directly by many Lactobacillus species. While some strains can metabolize galactose, it is not a primary sugar that they ferment, making galactose the least compatible option in this context. This distinction reflects the metabolic pathways and energy requirements of Lactobacillus, which favor sugars that readily convert into lactic acid during fermentation.