Producción CyT
Congreso
Autoría
Olivella, Laura
;
Barengo, Pamela B.
;
Trod, B.
;
Derita, M.
;
ESPARIZ, MARTIN
;
Daurelio, Lucas D.
Fecha
2022
Editorial y Lugar de Edición
SAMIGE
Resumen
Información suministrada por el agente en
SIGEVA
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 S...
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<0.05). On the other hand, to determine the optimum dilution of SS9 to use, growth curves were made with BioTek Synergy ® equipment. The growth curves of Xcc were made by triplicate in plates of 96 wells with tree dilutions of SS9 (1/2; 1/8 and 1/32) with LB as cultured medium. The negative control of growth was a mixture of SS9 and LB, and the positive control was a mixture of a suspension of Xcc (108 UFC/ml) and LB. Each condition was assayed for triplicated and the equipment was set to measure every 20 minutes at 30 °c for 15 hours. The growth curves were analyzed with Gompertz nonlinear regression model to obtain the alpha and gamma parameters. Besides, a significant difference in the average in alfa parameter (maximum growth) was found for the ½ dilution (0.41± 0.02) (Kruskal-Wallis p<0.05). In conclusion, the inhibitory activity of SS9 in field conditions was demonstrated and the optimum dilution was determined with growth curves. These results suggest the potential use of S9 as a canker control agent and further studies will be necessary to identify the Xcc-inhibitor metabolite.
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Palabras Clave
Xanthomonas citriBACILLUS