An introduction to rod-shaped lactic-acid bacteria.

The genus Lactobacillus is mainly found in the intestinal tract of healthy humans and animals as well as in fermenting vegetables or plant materials, such as silage. It has a moderate diffusion in meat products and is rarely found in wines and beers. On the other hand, rod-shaped lactic-acid bacteria are largely used in the preparation of a variety of foods and feed products. As starter cultures, they are omnipresent in cheeses and dairy manufacturing. Specific fermentation processes have been developed in order to encourage the growth of the desired species, some of which are fastidious organisms such as L. delbrueckii ssp. bulgaricus, L. helveticus and L. sanfrancisco. In addition, a promising and interesting perspective is the use of rod-shaped lactic-acid bacteria, primarily L. acidophilus, L. reuteri and L. salivarius as probiotic starters to preserve the natural biological equilibrium of the intestinal tract.