The antiphage effect of ribonuclease binase in

Ribonuclease secreted by Bacillus pumilus (binase) exerts antiviral effect against viruses of animals and plants whereas its antiviral potential against viruses of bacteria has not been studied in deep. Here, the antiphage effect of binase was explored in a population of Bacillus subtilis since this species of Bacillus genus lacks genes homologous to binase. A bacteriophage active against B. subtilis was isolated from soil samples obtained from root zones of trees in urban park. It was shown that exogenously applied binase interfered with phage reproduction in B. subtilis. Binase synthetized endogenously from a chromosomally integrated gene in a recombinant strain of B. subtilis reduced page titer by two orders of magnitude in comparison to the parent B. subtilis strain without binase gene. The antiphage effect of binase was more pronounced when the number of phage particles was small. Therefore, it was found that expression of ribonuclease binase in B. subtilis can limit phage infection.