Biosurfactants produced by the novel strain Bacillus subtilis H1 as an efficient tool to biocontrol fungal diseases of tomato and wheat

Abstract

Plant fungal diseases cause up to 15-20% and, in extreme cases, up to 60% yield loss globally. The use of chemical pesticides for the suppression of fungal plant diseases has many negative consequences for the environment. Therefore, new alternatives to suppress fungal pathogens are actively sought. In this present study, biosurfactants produced by the novel strain of Bacillus subtilis H1 were monitored for their ability to inhibit the growth of phytopathogens Fusarium oxysporum f. sp. lycopersici and Alternaria spp in in vitro and in vivo experiments. In the in vitro experiment, the treatment of tomato leaves with a biosurfactant fully inhibited the growth of F. oxysporum, and reduced the growth of Alternaria spp mycelium by 11.5 times at a concentration of 1000 mg/l. In the in vivo experiment, the use of a biosurfactant reduced the degree of damage to tomato and wheat plants, but less than in the in vitro experiment. In the case of tomato leaves infected with F. oxysporum and Alternaria spp and treated with 1000 mg/l biosurfactants, a decrease of 2.6 and 2.1 times was determined relative to infected but intreated leaves. For wheat leaves, the decrease was by 1.6 and 2.0 times, respectively. It can be concluded that biosurfactants produced by B. subtilis H1 are promising to be used for fungal pathogens biocontrol.