Production of high-value added exopolysaccharide by biotherapeutic potential Lactobacillus reuteri strain

Abstract

Exopolysaccharides (EPS) are produced by various microbial groups including bacteria. EPS produced from Lactobacilli is gaining popularity as a new generation functional food to replace various chemically synthesized food additives. EPS production by strains of L. reuteri were reported previously in sourdough fermentation. The submerged cultivation of L. reuteri strain DSM 20016 T was optimised for crude EPS production. Initially, the factors controlling crude EPS generation were explored using one-at-a-time (OFAT). Among the investigated carbon sources, sucrose supplemented medium increased maximal crude EPS generation. Yeast extract was determined to be the greatest nitrogen source for increasing crude EPS and cell mass. Plackett-Burman experimental design (PBD) was employed to screen the important parameters impacting crude EPS production in the growing medium. Three important factors were identified: sucrose, yeast extract and sodium acetate. The RSM quadratic model for crude EPS generation was significant (R2:0.9373) and correlated with the observed response at roughly 94%. About 3.4 g L-1 crude EPS was produced under optimal fermentation conditions of sucrose (106.0 g L-1), yeast extract (30.0 g L-1) and sodium acetate (7.0 g L-1). This study shows the crude EPS synthesis of L. reuteri from sourdough can be used in submerged fermentation and biotechnological applications.