IS THE KNOWLEDGE OF LACTOCOCCI SUFFICIENT TO UNDERSTAND OTHER LACTIC-ACID BACTERIA

Basically, lactococci are the best known lactic acid bacteria. A bette r control of fermentations involving these bacteria supposes to enlarg e our knowledge of other lactic bacteria and to determine the properti es they have in common. With this in view, two examples of comparison between lactococci and mainly lactobacilli are illustrated cell surfac e-located proteins (S-layer proteins and proteinases) and lactose syst ems (transport and catabolism of lactose). Significant differences are noted between bacterial geni. S-layer proteins cover the cell surface of lactobacilli, but lactococci are devoid of this extra layer. Parti cular attention is given to mechanisms of protein binding to the cell wall. An intra-genus variability is also noted. For instance, two lact ose sytems are mainly detected in lactobacilli. The origins of this va riability are discussed.