GENETIC, PHYSIOLOGY, AND ECOLOGY OF STRESS RESISTANCE IN LACTOBACILLUS PLANTARUM, A MULTIFUNCTIONAL STARTER FOR THE PRODUCTION OF FERMENTED FOODS AND NUTRACEUTICALS

摘要

Lactic acid bacteria (LAB) are a heterogeneous bacterial group important both in food fermentations and as probiotics. To date, 90 LAB genomes have been sequenced and the body of knowledge on important species is impressive. Lactobacillus plantarum is a versatile species which is widespread in fermentation of foods of plant and animal origin, includes probiotic strains, and has a relatively large genome and diverse metabolic activities (Siezen et ai, 2010). LAB are exposed in foods or in the gastrointestinal tract to a variety of stresses to which they respond with adaptation mechanisms, which influence their performance and survival. All species show a generalized stress response during the stationary growth phase and are able to adapt following exposure to sub-lethal stresses during the exponential growth phase. As in other Gram+, stress response regulation mechanisms mediated by HrcA and CtsR control the expression of class I and class III stress response genes, respectively, even if some genes are subjected to dual regulation (van de Guchte et al., 2002).