Potential of a new strain of Bacillus amyloliquefaciens BUZ-14 to control Monilinia fructicola and M. laxa in peaches: preliminary studies

Monilinia fructicola and M. laxa produce large economic losses in stone fruits during their production and distribution, causing brown rot.
One of the alternatives to reduce its incidence is the use of antagonist microorganisms.
In this work, we have studied in vitro activity of B. amyloliquefaciens BUZ14. 24 h-old cultures, as well as endospores and cell-free supernatants (1:1, 1:4 and 1:10 dilutions) obtained after 72, 96 and 120 h of incubation at 30°C were tested against M. fructicola and M. laxa. In vivo activity of cultures and cells (10⁸, 10⁷ and 10⁶ CFU mL^-1) and cell-free supernatants (undiluted and 1:10 dilution) was also tested from 24, 48 and 72 h-old cultures.
Cultures showed percentages of in vitro growth inhibition of 70% for both species, while the reduction for endospores was different, 66 and 87% for M. fructicola and M. laxa, respectively.
However, cell-free supernatants obtained after 72 h of incubation showed complete inhibition (100%). In contrast to these results, the maximum in vivo inhibitory activity was detected in 24 h-old cultures.
Thus, a minimum inhibitory concentration of 10⁷ cells mL^-1 was established since brown rot incidence was 0%. Cell-free supernatant (undiluted) also avoided fungal growth at all incubation times.
Experimental evidence suggests that B. amyloliquefaciens BUZ-14 controls brown rot in peaches, which demonstrates its biotechnological applications.

VIII International Postharvest Symposium: Enhancing Supply Chain and Consumer Benefits – Ethical and Technological Issues

H. Calvo, R. Oria, D. Blanco, M.E. Venturini

biocontrol, postharvest, brown rot, cells, supernatant

https://doi.org/10.17660/ActaHortic.2018.1194.34