Isolation of the Novel Strain Bacillus amyloliquefaciens F9 and Identification of Lipopeptide Extract Components Responsible for Activity against Xanthomonas citri subsp. citri

Abstract

Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a quarantine disease that seriously affects citrus production worldwide. The use of microorganisms and their products for biological control has been proven to be effective in controlling Xanthomonas disease. In this study, a novel Xcc antagonistic strain was isolated and identified as Bacillus amyloliquefaciens F9 by morphological and molecular analysis. The lipopeptide extract of B. amyloliquefaciens F9 (F9LE) effectively inhibited the growth of Xcc in an agar diffusion assay and restrained the occurrence of canker lesions in a pathogenicity test under greenhouse conditions. Consistent with these findings, F9LE treatment significantly inhibited the production of extracellular enzymes in Xcc cells and induced cell wall damage, with leakage of bacterial contents revealed by scanning electron microscopy and transmission electron microscopy analyses. In addition, F9LE also showed strong antagonistic activity against a wide spectrum of plant pathogenic bacteria and fungi. Furthermore, using electrospray ionization mass spectrometry analysis, the main antimicrobial compounds of strain F9 were identified as three kinds of lipopeptides, including homologues of surfactin, fengycin, and iturin. Taken together, our results show that B. amyloliquefaciens F9 and its lipopeptide components have the potential to be used as biocontrol agents against Xcc, and other plant pathogenic bacteria and fungi.

Drought-Tolerant Landrace Rice Norungan Harbors Novel Putative Competitive Endophytes

“…In the recent past, several rice endophytes were reported as antagonists against Xoo, which include Pseudomonas putida, and Metarrhizium anisophile (Saikia and Bora 2021), Azospirillum (Yasuda et al,2009), Paenibacillus polymyxa (Choi et al,2022). The antagonists against Rhizoctonia reported were Bacillus subtilis, B. nakamurai (Wang et al,2022), and Lysinibacillus sphaericus (Shabanamol et al,2021). Our findings are following the earlier reports that endophytic Firmicutes are potential antagonists against rice bacterial and fungal pathogens.…”

Control of Maize Sheath Blight and Elicit Induced Systemic Resistance Using Paenibacillus polymyxa Strain SF05

“…Similar with some Bacillus and Paenibacillus strains, P. polymyxa exhibited a strong ability to inhibit the growth of pathogens, which could be used to control some plant disease. It was also reported that B. velezensis CE100, B. amyloliquefaciens F9 and B. velezensis VB7 could be used against F. oxysporum effectively [ 26 , 27 , 28 ]. Likely, P. polymyxa strain SF05 could also inhibit the growth of the fungi, suggesting the strain might also help to control the disease caused by F. oxysporum in strawberry and banana.…”

“…In addition, B. amyloliquefaciens F9 was also found to be able to control citrus canker caused by Xanthomonas citri subsp. citri [ 28 ]. Therefore, it might be a new insight for P. polymyxa strain SF05 to control the bacterial diseases.…”

Genetic diversity of enterotoxigenic Bacillus cereus strains in coriander in southwestern Mexico

“…citri, Erysiphe heraclei, Macrophomina phaseolina, Fusarium oxysporum f. sp. Fragariae, Sclerotinia sclerotiorum , tobacco streak virus, and tomato spot virus ( Wang et al, 2022 ; Hong et al, 2022 ; Saravanan et al, 2021 ; Ahmed et al, 2021 ). Also, has been described the bioremediation activity of some strains against heavy metals and pyrethroid-type pesticides such as cypermethrin and fenpropathrin ( Bhatt et al, 2021 , 2020 ; Xiao et al, 2015 ; Chen et al, 2012 , 2014 ; Arora, 2020 ).…”