Abstract
It was found that if introduced into a nutrient medium of 0.05-1 g/L nano-SiO2, the oxidant activity (OA) of the culture medium (CM) of bacilli increased by 43.2-60.1 % and the antioxidant activity (AA) decreased by 4.5-11.8 %. SiO2 nanoparticles had different effects on antiradical activity (ARA) of the CM of Bacillus subtilis IMV B-7023. In particular, nano-SiO2 had no significant effect on the ability of the CM of bacilli to inactivate the 2.2-diphenyl-1-picrylhydrazyl (DPPH·) free radical. However, for the content of the nanomaterial of 0.01-1 g/L decreased hydroxyl radical scavenging in the CM of B. subtilis IMV B-7023 on 7.2-17.6 % compared with a control. Low doses of silica nanoparticles stimulated the reducing power of the CM of bacteria and then highly suppressed it.