21/09 – SEMINÁRIO DE QUALIFICAÇÃO (Doutorado) – GERODES VASCONCELOS DA COSTA

SEMINÁRIO DE QUALIFICAÇÃO (Doutorado)

GERODES VASCONCELOS DA COSTA

Use of Bacillus sp. S26 for the protection of tomato plants against Botrytis cinerea

Orientadora: Dra. Camille Eichelberger Granada

Banca Examinadora: Dra. Marcia Pinheiro Margis (PPGBM-UFRGS) e Dr. Igor Daniel Alves Ribeiro (Dep. de Microbiologia, Imunologia e Parasitologia – UFRGS)

21 de setembro de 2026 (segunda-feira)

10h30min

Presencial: Anfiteatro do Departamento de Genética da UFRGS (Campus do Vale, prédio 43312)

Abstract:

Plant inoculants composed of plant growth-promoting bacteria (PGPB) are important for agricultural production and can act through three main mechanisms: as biostimulants, biofertilizers, and/or biocontrol agents The development of sustainable agricultural strategies requires the identification of multifunctional microbial inoculants capable of promoting plant growth while suppressing phytopathogens. In this study, a rhizospheric bacterial isolate previously designated Bacillus sp. S26 was comprehensively characterized through genomic, in vitro, and in vivo approaches.  Whole-genome sequencing identified the strain as Bacillus velezensis, closely related to the model strain FZB42 and no detectable virulence-associated genes.

Genome mining revealed genes involved in plant growth promotion, including those related to siderophore biosynthesis, phosphate mobilization, phytohormone production, stress tolerance, and plant colonization. Our study identified 17 biosynthetic gene clusters associated with the production of surfactin, fengycin, iturin-type compounds, bacillibactin, difficidin, bacillaene, and macrolactin. MALDI-TOF analyses confirmed the production of fengycin and iturin-related metabolites. In vitro assays demonstrated broad-spectrum antagonistic activity against seven phytopathogenic fungi. In greenhouse experiments, inoculation with B. velezensis S26 promoted tomato plant growth.