| Abstract [eng] |
The global agricultural industry faces significant challenges due to the annual loss of crops caused by diseases. Current measures employed to control these diseases, such as the heavy use of pesticides and antibiotics, present additional environmental and health concerns. To address these challenges and reduce the reliance on chemically toxic agents, alternative strategies are being explored. One such strategy involves the use of bacteriocins and bioactive peptides, which exhibit antimicrobial properties. Bacteriocins have been studied for a long time, but little is known about the use of bacteriocins in agriculture. These antimicrobials possess potent killing action, high stability, and low toxicity to humans, making them suitable alternatives to chemically toxic agents. While bacteriocins offer a promising alternative to synthetic chemicals in agriculture, the challenges associated with their use must be addressed through further research, regulation, and evaluation of their potential efficacy. Further research is necessary to optimize their production and develop efficient delivery systems for agricultural applications. The aim of this study was to isolate and purify bacteriocin active against phytopathogenic bacteria. To isolate bacterial strains from the soil, they were grown on NB, 10:NB, BHI and LB medium, at 30°C. 51 isolates were obtained and 11 isolates with antibacterial activity were identified by applying the spot on a lawn assay. By culturing isolates on selective Ashby's Mannitol Agar medium, it was determined that RL2, RL6, and BR2 isolates can use atmospheric nitrogen as a nitrogen source. 16S rRNA BLASTn and phylogenetic analysis indicated that BL1, BL5, BL11, BL17, BL25, BL26, and RL7 isolates belongs to Bacillus genus, and BR2, RL2 and RL6 isolates belongs to Pseudomonas genus. The spot on a lawn assay revealed that Bacillus sp. BL5 strain’s supernatant inhibited growth of S. scabiei DSM 41658 and P. syringae DSM 50315 phytopathogens. Analysis of Bacillus sp. BL5 isolate’s supernatant indicated that peptide with antibacterial activity has a molecular weight of ~3.5 kDa. Crude extraction of antibacterial peptide from Bacillus sp. BL5 strain’s supernatant was achieved by using ammonium sulphate precipitation method. To isolate bacteriocin from bacteria, different liquid chromatography systems were used. Purification by anion- exchange chromatography was partially successful, but additional purification steps were needed. |
