Study of the Strain Bacillus pumilus B-13176 and Its Metabolites with Fungicidal and Antibacterial Activities against Aspergillus niger and Staphylococcus aureus (MRSA)

Abstract

Strain B-13176, which manifests antibacterial and fungicidal activity, has been isolated via the screening of spore-forming bacteria and identified as Bacillus pumilus based on an analysis of variable regions of 16S RNA sequences. The cultural and morphological characteristics of the strain were studied, the dynamics of the synthesis of fungicidal and antibacterial metabolites and their location in culture were determined, and their resistance to physicochemical factors was investigated. It was shown that the strain possesses a pronounced activity against Aspergillus niger fungi and methycillin-resistant Staphylococcus aureus (MRSA) bacteria. The culture liquid of the strain was fractioned via centrifugation, ultrafiltration, extraction, and high-performance liquid chromatography (HPLC). Mass-spectrometry was used to show that the Bacillus pumilus B-13176 strain produces active, thermostable, protease-resistant metabolites of peptide origin that are located in the CL pellet (the fungicidal component) and supernatant (the antibacterial component).