Cultural Morphological and Biochemical Characteristics of Bacillus Subtilis Strains

Abstract

A decrease in therapeutic effect of some live lacto- and bifdobacteria-based drugs for veterinary use has been observed for the last 20 years that urges scientists to search for new microorganisms possessing probiotic properties. Many studies in this feld are focused onBacillus subtilisthat is widespread in the environment and non-pathogenic for animals and humans. Results of tests ofBacillus subtilisfor its biological properties and antagonistic activity aimed at optimization of methodical approaches for detection of strain with the highest antagonistic effect on some opportunistic microorganisms and their further use as probiotics are described. Cultural morphological and biochemical characteristics of the tested strains conformed to the species characteristics ofBacillus subtilis.Tested strains were nonpathogenic for white mice. Tests showed that spore biomass could be prepared both in liquid and on solid nutrient media. Methodically, spore biomass preparation in liquid nutrient medium is preferable. The tests showed that spores emerged from anabiosis non-uniformly and it depended on original seed spore storage period. Spore cultures stored less than one year emerged from anabiosis more quickly. It was found that the spores formed more readily when the cultures were aerated with oxygen as well as that lag-phase culture medium had a stimulating effect onBacillus subtilisspore germination.Bacillus subtilisstrains were found to have antagonistic effect onEscherichia coli, SalmonellaandStaphylococcus. Area of growth inhibition of the said bacteria was 15–20 mm. TestedBacillus subtilisstrains could be proposed for use as probiotics.

Antagonistic effect of Bacillus subtilis isolated and identified from different honey species against Klebsiella pneumoniae bee pathogens

“…Frequent and long-term use of antibiotic therapy has led to significant resistance of these microorganisms, characterized by the presence of genes that encode the ability to synthesize carbapenemases (Polischouk et al, 2017;Bozhkova et al, 2020;Nevezhina, 2021). The genetic sequences encoding these bacterial enzymes constitute unique "mobile genetic structures" that promote the rapid spread of infections in farms, hospitals, clinics (Rusaleyev et al, 2019), and apiaries . Regulation of the imbalance of the interaction of the components of the intestinal microbiota of the bee is a specific, modulating effect of alternative antimicrobial agents.…”

“…Such an inhibitory effect was found in saprophytic sporeforming microorganisms of Bacillus subtilis species (Zulkhairi Amin et al, 2017;Irkitova et al, 2018). The primary habitat of this microorganism is the soil, rhizome, and pollen of flowering plants (Rusaleyev et al, 2019). The affinity of antimicrobial protein, synthesized by the mammalian macroorganisms and the bacillus metabolites, gives preference to Bacillus subtilis as a probiotic agent (Mnif et al, 2015;Sumi et al, 2015).…”