Professional Description:
A genus of bacteria of the family Lactobacillaceae, occurring as large, gram-positive, asporogenous, rod-shaped organisms. They are anaerobic or microaerophilic and occur widely in nature and in the human mouth, vagina, and intestinal tract. They are separable into two groups, the homofermentative group producing only lactic acid, and the heterofermentative group producing other end-products of fermentation.