Reducing the toxic effect of lead ions on Triticum aestivum L. and Sinapis alba L. under the action of the B. licheniformis RZn strain in an in vitro model

Environmental pollution with heavy metals, including xenobiotic elements with high cumulative characteristics, is currently an urgent problem. Lead is a priority pollutant of the first hazard class that enters the environment through fertilizers and as a result of technological emissions (dust, vapors, solutions), which easily settle on soil and water surfaces. Soil microorganisms of the genus Bacillus spp. with high accumulation characteristics can be used as effective sorbents of mobile forms of toxic elements. The paper presents results of experimental studies on the isolation and evaluation of the effectiveness of Bacillus spp. strains isolated from territories with high anthropogenic load. The use of the well diffusion method in combination with the serial dilution method, as well as the “replica” method with seeding on substrates with high cationic load by adding Pb(NO 3 ) 2 “P.A.” in concentrations of 0.031 M, 0.016 M and 0.008 M allowed isolation of a promising B. licheniformis RZn strain characterized by stable growth on media with Pb(NO 3 ) 2 addition at a concentration of 0.031 M and lead cation sorption rates from the substrate up to 65.39%. In a model experiment using test cultures of Sinapis alba L. and Triticum aestivum L., a reduction in the toxic effect of lead on germination rates as well as plant morphometric parameters was observed. This indicates the significant biological potential of the studied strain as a remediator of lead ions.