Lactic acid bacteria as starter cultures

The production of fermented foods today is based on the use of lactic acid bacteria (LAB) as starter cultures, in order to initiate and provide controlled and predictable fermentation. LAB starters are primarily used because of their ability to produce lactic acid from lactose, and for consequent pH reduction, but also for their ability to improve the quality and functionality of fermented foods. In particular, the following aspects are very interesting: the type of starter and the metabolisms of lactose, citrate, nitrogen and lipids, bacteriocins and exopolysaccharides production. Nowadays effort has to be made to search for potential starter microorganisms from wild strains recoverable from raw materials. The most important new aspects that have to be considered in this trend are first microbial genome sequences; and secondly possible interactions (positive and negative) among different microbial groups living together in the same system (i.e. food system, human/animal intestine system etc.) and influencing each other.