Comparative assessment of the level of tolerance of <I>Bacillus subtilis</I> soil isolates in relation to chemical copper compounds

Abstract

Relevance. The biological potential of microorganisms due to the high level of physiological and adaptive characteristics to the action of abiotic factors (the formation of resistant forms) and has a wider range of applications in contrast to substitution therapy. Our work presents experimental data on the assessment of the level of tolerance of soil isolates of Bacillus subtilis in relation to various chemical compounds of copper and the degree of influence of a massive cationic load on the growth of the most resistant strains.Methods. To implement the tasks set, we used the methods of isolation and identification of pure cultures of microorganisms, the diffusion method of agar wells (assessment of the inhibitory characteristics of chemical compounds), and the nephelometric method (the effect of heavy metals on the growth of microorganisms).Results. The most resistant strain to chemical stress is the B. subtilis P-8, isolate, which exhibits resistance to extremely high concentrations of copper: CuCl2 · 7H2O and CuSO4 — 0.125 M/l, Cu(CH3COO)2 — 0.250 M/l, while the strain B. subtilis P-6 is the most sensitive to two of the three chemicals. When conducting studies to assess the level of copper sulfate fusion on the growth of the population of strains selected by us, it was found that this compound has a pronounced prolonging effect on the growth of the cell population of B. subtilis P-6 and B. subtilis P-8 with an increase in the time of onset of the stationary phase of growth by 6 hours, relative to benchmarks.