Characterization of potential probiotic strain, L. reuteri B2, and its microencapsulation using alginate-based biopolymers

Abstract

In this study, Lactobacillus reuteri B2was isolated fromthe feces of C57BL/6 mice and assessed on probiotic activity. L. reuteri B2was identified by 16S rDNA sequencing, which the cell viability in acidic conditions at pH 2.0was 64% after 2 h, and in the presents of 0.30% of the bile salts, after 6 h, was 37%. Antimicrobial assay with L. reuteri B2 showed maximumdiameters against Klebsiela oxytoca J7 (12.5±0.71mm).Wefurther hypothesized if L. reuteri B2 strain in the free form can survive all conditions in the gastrointestinal tract (GIT) then the utilization of the appropriate biomaterials would ameliorate its stability and viability in GIT. L. reuteri B2 was microencapsulated into sodium alginate-(Na-alg) and different content of Na-alg and sodium maleate (SM) beads. Characterization materials enveloped their thermal characteristics (TGA/DTA analysis) and structure using: scanning electron microscopy (SEM), FTIR, and particle size distribution. The high survival rate of L. reuteri B2 at lowpH from2.0 to 4.0 and in the presence of the bile salts, at concentrations up to 0.30%, was obtained. L. reuteri B2 showed strong antimicrobial activity and the best protection microencapsulated with Na-alg + SM in simulated gastric juices (SGJ).