Modulating Exopolysaccharide Production in Lactic Acid Bacteria and Bifidobacteria: Insights from Physiological, Evolutionary, and Co-Culture Strategies

Lactic acid bacteria (LAB) and Bifidobacterium make exopolysaccharides (EPS), which positively affect the physicochemical and sensory properties of fermented food. The isolated EPS is also useful for improving viscosity, stability, and food textures, and also finds applications in the medical field. Thus, there is an increasing research focus on enhancing EPS production by these bacteria. Altering the growth media composition, by varying carbon and mineral sources, is a tested approach for such a purpose. Cultivation conditions like temperature, pH, and shaking also significantly influence EPS production in a strain-specific manner. Given the plausible role of EPS in stress tolerance, elevating EPS yield by exposure to certain stressors, such as bile, has been achieved. Advanced strategies such as evolutionary engineering and cross-kingdom ecological interactions of LAB, especially with yeast, also appear to be promising techniques for enhancing bacterial EPS yield and quality. This review elucidates recent research on all the above-mentioned ways of enhancing EPS production and the possible utility of such bacteria in industrial applications.