title: Surfactin triggers biofilm formation of Bacillus subtilis in melon phylloplane and contributes to the biocontrol activity.
abstract: The biocontrol activity of many Bacillus species has been traditionally related to the direct antagonism of pathogens. In previous works, we reported that B. subtilis strain UMAF6614 was an efficient biocontrol agent that produced bacillomycin, fengycin and surfactin lipopeptides. Bacillomycins and fengycins were shown to have antagonistic activity towards fungal and bacterial pathogens of cucurbits; however, the functionality of surfactin remained unclear. In this study, the role of surfactin in the biocontrol activity of this strain was investigated. We observed that a deficiency in surfactin production led to a partial reduction of disease suppression by this biocontrol agent, which coincided with a defect in biofilm formation and the colonization of the melon phylloplane. These effects were due to a dramatic reduction in the production of exopolysaccharide and the TasA protein, which are the two major components of the extracellular matrix. We propose that the biocontrol activity of this strain is the result of the coordinated action of the three families of lipopeptides. B. subtilis UMAF6614 produces surfactin to trigger biofilm formation on melon phylloplane, which ensures the long-term persistence and the adequate secretion of suppressive lipopeptides, bacillomycins and fengycins, which efficiently target pathogens.
authors.affiliation: Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' - Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain.
authors.forename: Houda
authors.initials: H
authors.lastname: Zeriouh
authors.forename: Antonio
authors.initials: A
authors.lastname: de Vicente
authors.forename: Alejandro
authors.initials: A
authors.lastname: Pérez-García
authors.forename: Diego
authors.initials: D
authors.lastname: Romero
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D018441:Biofilms / Q000254:growth & development*; D061046:Biological Control Agents; D019662:Cucurbitaceae / Q000382:microbiology*; D015870:Gene Expression; D055666:Lipopeptides / Q000096:biosynthesis* / Q000172:deficiency / Q000378:metabolism; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000172:deficiency / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D061046:Biological Control Agents; D055666:Lipopeptides; D010456:Peptides, Cyclic; D011135:Polysaccharides, Bacterial; C119938:TasA protein, Bacillus subtilis; C049972:fengycin; C009365:surfactin peptide