Final answer:
The live bacteria in sour beers is called Lactobacillus, responsible for the sour taste due to lactic acid production, while Brettanomyces is a wild yeast contributing additional flavors.
Step-by-step explanation:
The live bacteria in sour beers are primarily Lactobacillus. These bacteria are responsible for producing lactic acid which contributes to the tart and tangy flavor characteristic of sour beers. Brettanomyces, although often erroneously referred to as bacteria, is actually a type of wild yeast that can also be present in sour beers and provide additional funky and earthy flavors.
Unlike Lactobacillus, Brettanomyces is known for its involvement in the production of certain aromatic compounds. It is important to distinguish between Lactobacillus and yeast as they are different types of microorganisms and play separate roles in the fermentation process.