2. Proteases
Microorganisms represent an excellent source of enzymes owing to their broad biochemical diversity and
their susceptibility to genetic manipulation. Microbial proteases account for approximately 40% of the
total worldwide enzyme sales [5]. Proteases from microbial sources are preferred to the enzymes from
plant and animal sources since they possess almost all the characteristics desired for their
biotechnological applications.
In contrast with the well characterized proteolytic system of dairy LAB, the proteolytic system of
fruits, fruits juices and fermented fruits LAB remains not extensively studied. Although Davis et al. [6]
failed to detect protease activity in several wines LAB examined, including several strains of oenococci,
pediococci and lactobacilli, the research group of Manca de Nadra demonstrated by the first time the
production, characterization, regulation and purification of an extracellular proteases by strains of
Oenococcus oeni [7-13], (formerly Leuconostoc oenos; Dicks et al. [14]. As the fermented must,
produced from grapes, is a nutritionally poor ecological niche the LAB must develop strategies to
survive and growth. Guilloux-Benatier et al. [15] reported that wine have few nutrients available for
LAB in general and specifically for O. oeni strains