RESUMEN
Bacillus thuringiensis is an entomopathogen belonging to the Bacillus cereus clade. We isolated a tetracycline-resistant strain called m401, recovered it from honey, and identified it as Bacillus thuringiensis sv. kumamotoensis based on the average nucleotide identity calculations (ANIb) comparison and the analysis of the gyrB gene sequences of different B. thuringiensis serovars. Sequences with homology to virulence factors [cytK, nheA, nheB, nheC, hblA, hblB, hblC, hblD, entFM, and inhA] and tetracycline resistance genes [tet(45), tet(V), and tet(M)/tet(W)/tet(O)/tet(S) family] were identified in the bacterial chromosome. The prediction of plasmid-coding regions revealed homolog sequences to the MarR and TetR/AcrR family of transcriptional regulators, toxins, and lantipeptides. The genome mining analysis revealed 12 regions of biosynthetic gene clusters responsible for synthesizing secondary metabolites. We identified biosynthetic gene clusters coding for bacteriocins, siderophores, ribosomally synthesized post-translationally modified peptide products, and non-ribosomal peptide synthetase clusters that provide evidence for the possible use of Bt m401 as a biocontrol agent. Furthermore, Bt m401 showed high inhibition against all Paenibacillus larvae genotypes tested in vitro. In conclusion, Bt m401 owns various genes involved in different biological processes, such as transductional regulators associated with antibiotic resistance, toxins, and antimicrobial peptides with potential biotechnological and biocontrol applications.
Asunto(s)
Bacillus thuringiensis , Bacillus thuringiensis/genética , Microbiología de Alimentos , Filogenia , Bacillus cereus , Antibacterianos/farmacología , Tetraciclina/metabolismoRESUMEN
This study aimed to evaluate the performance of Hicrome Bacillus™ agar for isolation and rapid identification of the aerobic spore-forming bacteria most frequently found in honey samples. A collection of 197 bacterial isolates of Bacillus, Brevibacillus, Lysinibacillus, Paenibacillus, and Rummeliibacillus belonging to different species that have been reported in honey were screened for their abilities to grow and for their colony colors and medium appearance in HiCrome Bacillus agar. Also, 21 strains from culture collections were used for comparison and quality controls. A flowchart utilizing a combination of colony and media characteristics in the chromogenic medium and a set of simple biochemical and morphological tests were elaborated for quick presumptive identification. A procedure for direct isolation from honey samples was developed. In conclusion, HiCrome Bacillus agar in combination with simple microbiological tests was highly useful for rapid and reliable identification of most Bacillus, Brevibacillus, Lysinibacillus and Paenibacillus species commonly found in honey samples facilitating isolation from polymicrobial honey.
Asunto(s)
Bacillaceae/aislamiento & purificación , Bacillus/aislamiento & purificación , Recuento de Colonia Microbiana/métodos , Miel/microbiología , Bacillaceae/clasificación , Bacillaceae/genética , Bacillaceae/crecimiento & desarrollo , Bacillus/clasificación , Bacillus/genética , Bacillus/crecimiento & desarrollo , Recuento de Colonia Microbiana/instrumentación , Microbiología de AlimentosRESUMEN
We report here the 6,092,003-bp draft genome sequence of Bacillus thuringiensis strain m401, a tetracycline-resistant isolate recovered from honey. The isolate contained three plasmids of 8,307 bp, 9,934 bp, and 69,561 bp and a tetracycline resistance gene with high homology to tet45 in a contig of 236,180 bp.
RESUMEN
The diversity of a collection of Agrobacterium rubi strains isolated from blueberries from different regions of Argentina was studied by conventional microbiological tests and molecular techniques. Results from biochemical and physiological reactions, as well as from rep-PCR and RFLP analysis of PCR-amplified 23S rDNA showed high phenotypic and genotypic intraspecific variation.
Asunto(s)
Agrobacterium/aislamiento & purificación , Arándanos Azules (Planta)/microbiología , Agrobacterium/genética , Argentina , ADN Bacteriano/análisis , ADN Bacteriano/genética , ADN Ribosómico/análisis , ADN Ribosómico/genética , Genes Bacterianos , Variación Genética , Genotipo , Fenotipo , Tumores de Planta/microbiología , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , ARN Bacteriano/genética , ARN Ribosómico 23S/genética , Ribotipificación , Microbiología del SueloRESUMEN
Se estudió la diversidad de una colección de cepas de Agrobacterium rubi aisladas de arándanos provenientes de distintas regiones de la República Argentina estableciendo su grado de heterogeneidad mediante pruebas microbiológicas clásicas y técnicas de biología molecular. Los resultados obtenidos en las pruebas bioquímicas y fisiológicas, así como mediante rep-PCR y RFLP del gen 23S ADNr, demostraron una alta variabilidad intraespecífica, tanto fenotípica como genotípica
The diversity of a collection of Agrobacterium rubi strains isolated from blueberries from different regions of Argentina was studied by conventional microbiological tests and molecular techniques. Results from biochemical and physiological reactions, as well as from rep-PCR and RFLP analysis of PCR-amplified 23S rDNA showed high phenotypic and genotypic intraspecific variation
