Szczepy Bacillus i Pseudomonas zdolne do produkcji biosurfaktantów – charakterystyka mechanizmów aktywności przeciwgrzybowej i ocena potencjału aplikacyjnego w obecności wybranych zanieczyszczeń antropogennych

Abstract

The study investigates the antifungal activity of Bacillus and Pseudomonas strains capable of biosurfactant production, particularly in the presence of anthropogenic pollutants (synthetic pesticides, microplastics, and azo dyes). The goal was to gain a deeper understanding of how these pollutants influence the efficacy of microbiological plant protection agents. The research began with the characterization of biosurfactants produced by 80 rhizosphere bacterial strains (77 from genus Bacillus and three from genus Pseudomonas). Over the course of the research, the number of strains was gradually reduced to focus on those with the most promising characteristics. The bacterial strains were evaluated for their ability to inhibit Fusarium fungi through both non-volatile metabolites and volatile organic compounds. Their effects on cucumber seedling root growth were assessed, both in the presence and absence of Fusarium fungi. The study also explores the influence of various anthropogenic pollutants on biosurfactant production, bacterial growth, and antifungal activity. The results showed that anthropogenic pollutants can influence the biosurfactant production and antifungal activity of bacterial strains in various ways. The effects were dependent on the bacterial and fungal strains, as well as the specific pollutants involved. Despite the varied effects, Bacillus sp. Kol B9 was identified as a promising candidate for biopesticide applications, as it did not negatively impact cucumber root growth and maintained antifungal activity even in the presence of pollutants. However, the presence of multiple pollutants could compromise the effectiveness of some bacterial strains, highlighting the importance of considering environmental factors when evaluating biopesticide potential.