Effects of environmental stresses on the physiological characteristics, adhesion ability and pathogen adhesion inhibition of Lactobacillus plantarum KLDS 1.0328

Abstract

Changes in the physiological state and adhesion of probiotics under stresses affect their interaction with the host. The effects of osmotic (3% NaCl, 6% NaCl, and 3% NaCl + 3% KCl), acid (pH 5.0), and alkali (pH 8.0) stress on the physiological characteristics, adhesion ability and pathogen adhesion inhibition of Lactobacillus plantarum KLDS 1.0328 were investigated. The results showed that 6% NaCl resulted in lower acid production, growth and antimicrobial activity of cells compared to control and 3% NaCl treatment. Reduced surface hydrophobicity, aggregation ability, adhesion ability and pathogen adhesion inhibition were observed when L. plantarum KLDS 1.0328 was exposed to 6% NaCl. These changes were weakened when NaCl was partially replaced by KCl. Exposure to stresses other than alkali stress significantly increased the ratio of unsaturated fatty acid to saturated fatty acid in the cell membrane. The autoaggregation and adhesion ability of cells were increased under pH 5.0 treatment. The results demonstrated that the abilities of cells to adhere and inhibit pathogen adhesion were significantly positively correlated with the ability to coaggregate with pathogens. This study provides a basis for our understanding of the response of L. plantarum to stresses and the related molecular mechanisms.