Effect of Natural Polysaccharides on the Population Density of Klebsiella pneumoniae Isolates In Vitro

The purpose of the work was to study the influence of natural polysaccharides—arabinogalactan, galactomannan, and carrageenan—on the growth of Klebsiella pneumoniae strains. It was found that carrageenan, especially in high concentrations, most effectively stimulated the growth of these microorganisms. A dependence of the effect of galactomannan on the concentration used was discovered: an inhibitory effect was detected in high doses and a stimulating effect in low doses. Arabinogalactan inhibited the growth of Klebsiella pneumoniae, which could be due to phenolic impurities (bioflavonoids), the presence of which is typical of this polysaccharide. Moreover, this polysaccharide at a concentration of 0.1 mg/mL completely blocked the growth of the studied microbial strains, which can be explained by the antibacterial effect of flavonoids.