Genomic Analysis and Secondary Metabolites Production of the Endophytic <i>Bacillus velezensis</i> Bvel1: A Biocontrol Agent against <i>Botrytis cinerea</i> Causing Bunch Rot in Post-Harvest Table Grapes
Kallimachos Nifakos,
Polina C. Tsalgatidou,
Eirini-Evangelia Thomloudi,
Aggeliki Skagia,
Dimitrios Kotopoulis,
Eirini Baira,
Costas Delis,
Konstantinos Papadimitriou,
Emilia Markellou,
Anastasia Venieraki,
Panagiotis Katinakis
Affiliations
Kallimachos Nifakos
Laboratory of General and Agricultural Microbiology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Polina C. Tsalgatidou
Laboratory of General and Agricultural Microbiology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Eirini-Evangelia Thomloudi
Laboratory of General and Agricultural Microbiology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Aggeliki Skagia
Laboratory of General and Agricultural Microbiology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Dimitrios Kotopoulis
Laboratory of General and Agricultural Microbiology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Eirini Baira
Laboratory of Toxicological Control of Pesticides, Scientific Directorate of Pesticides’ Control and Phytopharmacy, Benaki Phytopathological Institute (BPI), 8 St. Delta Street, Kifissia, 14561 Athens, Greece
Costas Delis
Department of Agriculture, University of the Peloponnese, 24100 Kalamata, Greece
Konstantinos Papadimitriou
Department of Food Science and Technology, University of the Peloponnese, 24100 Kalamata, Greece
Emilia Markellou
Scientific Directorate of Phytopathology, Benaki Phytopathological Institute (BPI), 14561 Athens, Greece
Anastasia Venieraki
Laboratory of Plant Pathology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Panagiotis Katinakis
Laboratory of General and Agricultural Microbiology, Crop Science Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
Botrytis bunch rot caused by Botrytis cinerea is one of the most economically significant post-harvest diseases of grapes. In the present study, we showed that the bacterial strain Bvel1 is phylogenetically affiliated to Bacillus velezensis species. The strain Bvel1 and its secreted metabolites exerted an antifungal activity, under in vitro conditions, against B. cinerea. UHPLC–HRMS chemical analysis revealed that iturin A2, surfactin-C13 and -C15, oxydifficidin, bacillibactin, L-dihydroanticapsin, and azelaic acid were among the metabolites secreted by Bvel1. Treatment of wounded grape berries with Bacillus sp. Bvel1 cell culture was effective for controlling grey mold ingress and expansion in vivo. The effectiveness of this biological control agent was a function of the cell culture concentration of the antagonist applied, while preventive treatment proved to be more effective compared to curative. The strain Bvel1 exhibited an adequate colonization efficiency in wounded grapes. The whole-genome phylogeny, combined with ANI and dDDH analyses, provided compelling evidence that the strain Bvel1 should be taxonomically classified as Bacillus velezensis. Genome mining approaches showed that the strain Bvel1 harbors 13 antimicrobial biosynthetic gene clusters, including iturin A, fengycin, surfactin, bacilysin, difficidin, bacillaene, and bacillibactin. The results provide new insights into the understanding of the endophytic Bacillus velezensis Bvel1 biocontrol mechanism against post-harvest fungal pathogens, including bunch rot disease in grape berries.
