Analysis of Adhesion Characteristics and Carbohydrate Metabolism Pathways of Three Lacticaseibacillus paracasei Strains from Different Sources Based on Genome Sequencing

Abstract

The surface characteristics and adhesion properties of Lacticaseibacillus paracasei ZY-1, derived from Tibetan kefir grains, and L. paracasei S-NA5 and S-NB, isolated from Xinjiang traditional fermented milk, were evaluated in vitro, and whole genome sequencing was performed to compare the difference among adhesion-related genes in the three strains. The gastrointestinal tolerance and adhesion properties of L. paracasei S-NB to Caco-2 cells were superior to those of S-NA5 and ZY-1. Moreover, two exopolysaccharide (EPS) synthesis gene clusters were found in each strain, and the EPS cluster 1 of strain ZY-1 differed significantly from that of S-NA5 and S-NB. Meanwhile, genes involved in lipoteichoic acid (LTA) synthesis and related domains of protein adhesins were predicted. The secondary structure prediction of the products encoded by the adhesion protein genes in S-NB showed that the secondary structure of 11 adhesion proteins was dominated by α-helix and random coil. Additionally, the complete metabolic pathways of lactose, galactose, fructi-oligosaccharide, inulin and human milk oligosaccharides were found in the three strains, which were all highly conserved.

Keywords

• lacticaseibacillus paracasei; intestinal adhesion; genome sequencing; adhesin; carbohydrate metabolism pathway