The biological activity of the plants of Lemna genus against pathogenic bacteria

The biological activity of the Lemna plant genus was studied in the populations of Erysipelothrix rhusiopathiae pathogenic bacteria. Aqueous solutions of in vivo secretions of Lemna plant genus were sterilized by vacuum filtration through the filters with pore diameter of 0.2 microns. After adding E. rhusiopathiae, the samples under study contained the secretions of Lemna plant genus in 1:10, 1:100, 1:1000 and 1:10000 dilutions. As a method of control, sterile water from the water supply was used in a volume similar to the samples, in which the same amount of E. rhusiopathiae was added. After a 48-hour exposure, the test samples were taken to determine the density of bacterial populations. It has been established that lifetime secretions of the Lemna plant genus have a stimulating effect on E. rhusiopathiae bacteria. The degree of this impact is directly dependent on the level of diluting plant secretions. In the freshwater ecosystems, the formations of Lemna trisulca, Lemna minor and Spirodela polyrrhiza plants may create favorable conditions for the existence of E. rhusiopathiae pathogenic bacteria which must be taken into account in the process of economic activity.