Cyclic lipopeptides from Bacillus subtilis PTKU12 inhibits cell growth of Phytophthora palmivora

Abstract

Abstract Background and Aim: Phytophthora palmivora is a fungal-like pathogen of the family Oomycete, which causes leaf fall disease in the para rubber tree resulting in economic loss. To inhibit fungal diseases, biocontrol agents like cyclic lipopeptides (CLPs) from Bacillus spp. have been introduced to reduce the usage of synthetic fungicides. This study aimed to use cyclic lipopeptides (CLPs) obtained from Bacillus subtilis as a biocontrol agent to inhibit P. palmivora. Materials & Methods: A dual culture assay was performed to select the antagonistic bacteria for extraction of the CLPs. Half-maximal effective concentration (EC50) and agar well diffusion assays were conducted to determine the efficacy of the CLPs extract from B. subtilis PTKU12 on the cell growth inhibition of P. palmivora. Results: As a result, the highest antagonistic activity from B. subtilis PTKU12 could control the P. palmivora growth. Moreover, the agar well diffusion assay presented the greatest ability of iturin A on the fungal inhibition with a statistically significant difference at 24 hr after treatment (p < 0.05). The CLPs extract additionally showed the highest efficacy for inhibiting the growth of P. palmivora at 48 hr and 72 hr after treatment, respectively. Conclusion: This study exhibited the antifungal potential of the Bacillus CLPs extract on inhibition of P. palmivora growth. Thus, this study provided an alternative option to manipulate the P. palmivora growth using Bacillus CLPs as a biocontrol agent for sustainable agriculture.