Antagonism of Bacillus safensis strain in field conditions against phytopathogenic bacteria Xanthomonas citri pv. Citri

OLIVELLA, LAURA; BARENGO, PAMELA B.; TROD, B.; DERITA, M.; MARTÍN ESPARIZ; DAURELIO, LUCAS D.

Cordoba

Congreso; XVIII Congreso Argentino de Microbiología Genera (SAMIGE); 2022

SAMIGE

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc), is a bacterial disease that affects all citrics. One alternative to manage it’s the use of antagonist bacteria. Previous studies demonstrated the antagonist activity of Bacillus safensis (S9) and their filtered supernatant (SS9) against Xcc in vitro conditions. The aim of this work was to investigate the antagonist activity of SS9 in field assays in grapefruits fruits (Citrus x paradisi) and determined the optimal dilution of SS9 for the use. First, the fruits of three plants were inoculated or not with a suspension of Xcc (108 UFC/ml) grown in Luria Bertania (LB) liquid medium. To avoid injuries, the inoculation was made with swabs. After an hour, three treatments were assayed: i) distilled water (control of no inhibition), commercial copper oxide (inhibition control), and the SS9 grown in liquid dextrose potatoe overnight. After two weeks, the fruits were harvested and the number of cankers per fruit was counted. A significant difference in the average number of cankers of 108.33± 77.34 was obtained with the SS9 (Kruskal-Wallis, p