Inhibition of the phytopathogenic fungi Curvularia lunata BM and Ganoderma sp. TB4 by antifungal compounds produced by Bacillus siamensis LDR grown on hanjeli (Coix lacryma-jobi L.) starch

Abstract

Bacillus siamensis LDR was tested for its potential as a biocontrol agent against the phytopathogenic fungi Curvularia lunata BM and Ganoderma sp. TB4. Fermentation of B. siamensis LDR for the production of antifungal compound was performed in modified Czapex-Dox broth using hanjeli (Coix lacryma-jobi L.) starch as carbon source. The Bacillus siamensis LDR inoculum was 105 CFU/ mL, and fermentation was conducted for up to 16 days. Antibiosis assay conducted to test the antifungal activity of filtrate medium. The results showed inhibition of C. lunata BM and Ganoderma sp. TB4 were 47.08% and 85.99%, respectively on 14th day of fermentation. Antifungal assay of the crude extract from filtrate medium revealed growth inhibition of C. lunata BM (60.70%) and Ganoderma sp. TB4 (65.25%). Thin layer chromatography of the crude extract revealed pink-colored spots indicative of lipopeptide compounds. Analysis of the crude extract by ultraperformance liquid chromatography-mass spectrometry was tentatively identified as iturin A, bacillomycin F, and surfactin.

Biosurfactant Activity of Bacillus sp. Strain LP04 Isolate and Its Antifungal Potency against Ganoderma boninense and Fusarium sp.

“…Growth inhibition of Ganoderma sp. by the bacterial crude extract was also reported with an inhibition percentage of 65.25±3.78% by the bacteria Bacillus siamensis LDR (Santoso et al 2022). Meanwhile, the value is higher than Bacillus sp.…”

Isolation and Genome-Based Characterization of Biocontrol Potential of Bacillus siamensis YB-1631 against Wheat Crown Rot Caused by Fusarium pseudograminearum

“…The antifungal compounds identified in cell-free culture filtrates of B. siamensis isolates include the lipopeptides, surfactin [22,[72][73][74], fengycin [9,19], and iturin A [22,74,75], bacillomycin F [22,74], bacillomycin D [73], and the catechol-based siderophore, bacillibactin [19]. The YB-1631 cell-free culture filtrate resulted in ruptured, swollen, and vacuolated hyphae of F. pseudograminearum.…”