Title : Secondary metabolites from Lactiplantibacillus plantarum and Lacticaseibacillus paracasei inhibited growth of Ralstonia syzygii subsp. Celebesensis (rsc), causal pathogen of banana blood disease
Abstract:
Banana blood disease is a banana wilt disease caused by Ralstonia syzygii subsp. celebesensis (RSC) and has significantly impacted the banana plantations particularly in Indonesia and Malaysia. In order to mitigate the damage caused by bacterial wilt in the banana industry, various control strategies have been explored, but none have proven to be completely effective. Biological control agents (BCA) acting as microbial biopesticides offer a promising solution by utilizing beneficial microorganisms that compete with pathogens. Among BCAs, lactic acid bacteria (LAB) have gained increasing attention in agriculture due to their ability to produce a wide range of antimicrobial compounds, while simultaneously enhancing plant growth and promoting soil health. This study aims to investigate the antimicrobial substances produced by Lactiplantibacillus plantarum and Lacticaseibacillus paracasei that can inhibit the growth of RSC from cell free supernatant (CFS) and liquid-liquid extraction (LLE) of LABs. The inhibitory effect of the LAB extracts against RSC were evaluated using agar well diffusion method. Liquid chromatography mass spectrometry analysis confirmed the bioactive metabolites with potential antibacterial activity against RSC are monoglucosyl-enterobactin from CFS-L. plantarum, canavanine and norspermidine in CFS-L. paracasei, sinapinic acid and D-glucono-1,5-lactone in LLE-L. paracasei. and lecanoric acid, lithocholic acid, orotic acid, and sterculic acid in LLE-L. plantarum. Scanning electron microscope has shown the disruption and the damaging of the Rsc cells in the treatment of LAB. These findings highlight the antimicrobial potential of L. plantarum and L. paracasei metabolites for biocontrol applications.
