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 2.0was64% after 2 h, and in the presents of 0.30% of the bile salts, after 6 h, was 37%. Antimicrobial assay with L. reuteri B2showed maximumdiameters against Klebsiela oxytoca J7 (12.5±0.71mm).Wefurther hypothesized if L. reuteriB2 strain in the free form can survive all conditions in the gastrointestinal tract (GIT) then the utilization of theappropriate biomaterials would ameliorate its stability and viability in GIT. L. reuteri B2 was microencapsulatedinto sodium alginate-(Na-alg) and different content of Na-alg and sodium maleate (SM) beads. Characterizationmaterials 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 4.0and in the presence of the bile salts, at concentrations up to 0.30%, was obtained. L. reuteri B2 showed strong antimicrobialactivity and the best protection microencapsulated with Na-alg + SM in simulated gastric juices(SGJ).