Project description:Southern corn leaf blight (SCLB), caused by Bipolaris maydis, poses a serious threat to maize production worldwide. In our previous study, Bacillus velezensis BV3 was isolated and demonstrated strong antagonistic activity against maize leaf spot pathogens and effective disease control in greenhouse experiments.
Project description:<p>In this study, a strain isolated from the surface of flue-cured tobacco leaves, identified as <em>Bacillus velezensis</em> HJ-16, was applied in the solid-state fermentation of tobacco leaves. This strain, known for producing thermally stable enzymes, including amylase, cellulase, and protease, significantly improved the sensory qualities of tobacco, enhancing aromatic intensity, density, and softness, while reducing irritation. Whole-genome sequencing and functional annotation revealed that <em>B. velezensis</em> HJ-16 possesses a single circular chromosome containing genes associated with enzyme production and metabolic activities, particularly in carbohydrate metabolism and amino acid metabolism. Untargeted metabolomics analysis identified significant changes in non-volatile metabolites induced by fermentation. These metabolites were enriched in pathways related to flavonoid biosynthesis, alkaloid biosynthesis, aromatic amino acid metabolism, lipid metabolism, and carbon metabolism. Metagenomic analysis showed that Bacillus became the dominant genus on the tobacco leaf surface following inoculation with <em>B. velezensis</em> HJ-16, altering the microbial community composition, reducing diversity and evenness, and enhancing microbial metabolic activity. These findings underscore the potential of <em>B. velezensis</em> HJ-16 as a biotechnological tool to improve tobacco leaf quality.</p>
Project description:Metabolites from different culture conditions of Bacillus velezensis. The purpose is to screen for antibacterial compounds against Flavobacteriaceae from Bacillus velezensis.
Project description:Cladobotryum mycophilum, the causative agent of cobweb disease on Agaricus bisporus results in significant crop losses for mushroom growers worldwide. Cobweb disease is treated through strict hygiene control methods and the application of chemical fungicides but an increase in fungicide resistant Cladobotryum strains has resulted in a need to develop alternative biocontrol treatment methods. The aim of the work presented here was to evaluate the response of C. mycophilum to a Bacillus velezensis isolate to assess its potential as a novel biocontrol agent. Exposure of 48 hr C. mycophilum cultures to 25% v/v 96h B. velezensis culture filtrate resulted in a 57% reduction in biomass (P < 0.0002), a disruption in hyphal structure and morphology, and the appearance of aurofusarin in culture medium. Proteomic analysis of B. velezensis culture filtrate revealed the presence of peptidase 8 (subtilisin), peptide deformylase and probable cytosol aminopeptidase which are known to induce cell disruption. Characterisation of the proteomic response of C. mycophilum following exposure to B. velezensis culture filtrate revealed an increase in the abundance of a variety of proteins associated with stress response (ISWI chromatin-remodelling complex ATPase ISW2 (+24 fold), carboxypeptidase Y precursor (+3 fold) and calmodulin (+2 fold). There was also a decrease in the abundance of proteins associated with transcription (40S ribosomal protein S30 (-26 fold), 40S ribosomal protein S21 (-3 fold) and carbohydrate metabolism, (L-xylulose reductase (-10 fold). The results presented here indicate that B. velezensis culture filtrate is capable of inhibiting the growth of C. mycophilum and inducing a stress response, thus indicating its potential to control this important pathogen of mushrooms.
Project description:Mutualistic interactions with beneficial microbes can influence plant physiology far beyond the point of initial contact, yet how host plants differentiate among microbial partners, and the consequences of that discrimination, remain poorly understood. Here, we investigate how Cucumis melo responds to early seed priming with two phylogenetically related Bacillus strains: B. subtilis NCIB3610 and B. velezensis FZB42. Despite exhibiting similar colonization patterns and persistence in the root system, these strains elicit distinct, strain-specific plant responses at the developmental, metabolic, and defensive levels. B. subtilis enhances radicle elongation and drought resilience through increased starch and L-tryptophan accumulation, while B. velezensis transiently represses early growth and reprograms host transcriptome and metabolome, including jasmonate-associated gene expression and flavonoid biosynthesis. Both treatments ultimately converge on improved performance in the phyllosphere, including enhanced resistance to Botrytis cinerea and a population of Tetranychus urticae, though via divergent physiological routes. These findings reveal that plants do not merely tolerate or benefit from microbial presence, but actively engage in partner-specific programming, even among closely related beneficial strains. This capacity for functional discrimination broadens our understanding of how mutualistic interactions are shaped and diversified in plant hosts.
Project description:To explore the adaptive strategies of wheat in response to beneficial, pathogenic and combined microorganisms, we performed the first comprehensive proteomic and in wheat roots after exposure to Bacillus velezensis CC09, Gaeumannomyces graminis var. tritici and their combined colonization, respectively.
Project description:Lecanicillium fungicola, the causative agent of dry bubble disease on Agaricus bisporus results in significant crop losses for mushroom growers worldwide. Dry bubble disease is treated through strict hygiene control methods and the application of chemical fungicides but an increase in fungicide resistant L. fungicola strains has resulted in a need to develop alternative biocontrol treatment methods. The aim of the work presented here was to evaluate the response of L. fungicola to a Bacillus velezensis isolate to assess its potential as a novel biocontrol agent. The bacterial species in Serenade, a commercially available biocontrol treatment was also included in this analysis. Exposure of 48 hr L. fungicola cultures to 25% v/v 96h B. velezensis culture filtrate resulted in a 45% reduction in biomass (P < 0.0002) and a disruption in hyphal structure and morphology. Characterisation of the proteomic response of L. fungicola following exposure to B. velezensis culture filtrate revealed an increase in the abundance of a variety of proteins associated with stress response (Norsolorinic acid reductase (+8 fold), isocitrate lyase (+7 fold) and MMS19 nucleotide excision repair protein (+4 fold). There was also a decrease in the abundance of proteins associated with transcription (40S ribosomal protein S30 (-33 fold), 60S ribosomal protein L5 (-45 foldThe results presented here indicate that B. velezensis culture filtrate is capable of inhibiting the growth of L. fungicola and inducing a stress response, thus indicating its potential to control this important pathogen of mushrooms.