Antimicrobial action of a bacterial consortium containing strains of the genus Bacillus
A.N. Irkitova, A.V. Grebenshchikova
Multicomponent biopreparations containing several symbiotic strains of microorganisms are gaining increasing popularity due to their heightened efficiency and improved biotechnological properties. In this connection, the purpose of this research was to study the antimicrobial action of a bacterial consortium consisting of 2 strains of Bacillus subtilis, as well as natural strains of the genus Bacillus. Strain of Escherichia coli was used as a test culture. We used methods of delayed (perpendicular bands, agar blocks, agar wells) and direct (co-incubating in a liquid medium) antagonism to achieve this aim. As a result, the antagonistic effect of the microbial composition against Escherichia coli was improved in compared to the single action of each strains included in the consortium. In agar media, the largest increase of the radius of zone of growth inhibition was noted from 6.65 mm to 10.67 mm, i.e. by 60.5%, and in liquid media – an improvement in the growth blocking index from 0.188 to 0.009, i.e. by 95.2%.