Exopolysaccharides produced by lactic acid bacteria: from health-promoting benefits to stress tolerance mechanisms

Abstract

A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and "ropy" products. Polysaccharides are involved in several mechanisms such as prebiosis and probiosis, tolerance to stress associated to food process, and technological properties of food. In this paper, we summarize the beneficial properties of exopolysaccharides (EPS) produced by LAB with particular attention to prebiotic properties and to the effect of exopolysaccharides on the LAB-host interaction mechanisms, such as bacterial tolerance to gastrointestinal tract conditions, ability of ESP-producing probiotics to adhere to intestinal epithelium, their immune-modulatory activity, and their role in biofilm formation. The pro-technological aspect of exopolysaccharides is discussed, focusing on advantageous applications of EPS in the food industry, i.e., yogurt and gluten-free bakery products, since it was found that these microbial biopolymers positively affect the texture of foods. Finally, the involvement of EPS in tolerance to stress conditions that are commonly encountered in fermented beverages such as wine is discussed.

Complete Genome Sequence of Streptococcus thermophilus KLDS 3.1003, A Strain with High Antimicrobial Potential against Foodborne and Vaginal Pathogens

“…Interestingly, the eps1C-ID and eps2C-2D produced by this organism suggests that it is a mixed producer of capsular and ropy EPS, a rare feature similar to high EPS-producing strains like S. thermophilus ASCC 1275 (Wu et al, 2014). This is however subject to further validation as many LABs produce different amounts and types of EPS under different conditions (Caggianiello et al, 2016). Furthermore, eps1C, 1D and eps2C, 2D function in chain length determination and eps A and B facilitate regulation of cell activities (Wu et al, 2014).…”

Controlled fermentation of the zoom-koom dough using two isolates of lactic acid bacteria (LAB 1 and LAB 5) as starter cultures: Effect on hygienic, rheological, nutritional and sensorial characteristics of the final product

“…The use of EPS-producing LAB isolates, for controlled fermentation could improve the physical stability of this beverage. Moreover, LAB are generally recognized as safe (GRAS) due to their long history of safe use in food production, and many of them have the qualified presumption of safety (QPS) status (Lahtinen et al, 2011;Caggianiello et al, 2016). Controlled fermentation using starter cultures allowed improvement of the hygienic and nutritional quality of traditional fermented products (Egounlety et al, 2007;Sawadogo-Lingani et al, 2008;Yao et al, 2009;Soma, 2014).…”

β-Glucans and Probiotics

“…Interestingly, since the survival of probiotics is conditioned by the ability to pass through the gastrointestinal tract, particular attention has been focused on microorganisms able to produce exopolysaccharides, due to the ability of these compounds to increase the tolerance to acid and enzymatic stress (Stack et al, 2010;Caggianiello et al, 2016). Accordingly, food matrices containing barley β-glucans were also able to ameliorate the persistence of Lactobacillus strains to in vitro gastrointestinal transit (Arena et al, 2014a).…”