RESUMEN
Peanut is susceptible to many diseases; among them, peanut smut disease caused by Thecaphora frezzii is the most damaging, causing yield losses of 30%. Fungicide treatment is not effective to control this disease. In this scenario, biological control would be an alternative to diminish the disease. Systemic resistance induced by a biotic agent is known to be effective against a broad spectrum of pathogens. In this study we evaluated the effect of different inoculation strategies of Bacillus sp. CHEP5, a peanut native strain, on peanut smut incidence and severity in field experiments. Peroxidase activity and accumulation of phenolic compounds were measured as changes associated with induced defensive traits. After three consecutive field trials, we found that Bacillus sp. CHEP5 inoculation protects peanut from T. frezzii because incidence and severity were reduced in two field trials. Furthermore, bacterial inoculation in the furrow followed by foliar application around the date of peg development would be the best strategy to control the disease. In addition, a correlation was found between increase in plant phenolic content and decrease in smut disease parameters. Thereafter, we concluded that Bacillus sp. CHEP5 may reduce smut as a result of plant defence response induction.
Asunto(s)
Arachis , Bacillus , Resistencia a la Enfermedad , Enfermedades de las Plantas , Bacillus/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Arachis/microbiología , Resistencia a la Enfermedad/efectos de los fármacos , Fenoles/metabolismoRESUMEN
The cultivation of marine shrimp is one of the fastest growing activities in the world. However, the emergence of diseases has resulted in a decrease in production and losses for the sector. Probiotics emerged as an option to the use of antibiotics to control these pathogens. The efficiency of applying this technology depends on the characteristics of the bacterial agents and their bioavailability in the shrimp intestine. The objective is to evaluate the viability and efficiency of bacteria isolated from the digestive tract of healthy crustaceans as probiotic agents in the cultivation of shrimp Litopenaeus vannamei. Eighteen strains of the genus Bacillus belonging to the following species were tested: Bacillus sp., B. cereus, B. thuringiensis, B. circulans, B. megaterium, B. subtilis and B. agaridevorans. Bacterial isolates were subjected to characterization as potential probiotics. The test results were considered satisfactory; thus, the tested strains have potential for use as probiotics in shrimp culture. Treatments that used of the genus Bacillus had reduced growth of the genus Vibrio after infection, both in the intestinal contents and in the intestine. With the results obtained, it can be suggested that further research be carried out on the probiotic potential of Bacillus sp.
Asunto(s)
Bacillus , Tracto Gastrointestinal , Probióticos , Animales , Bacillus/fisiología , Bacillus/clasificación , Bacillus/aislamiento & purificación , Tracto Gastrointestinal/microbiología , Penaeidae/microbiología , Vibrio/fisiologíaRESUMEN
Bacterial spores in materials and equipment pose significant biosecurity risks, making effective disinfection crucial. This study evaluated Ortho-phthalaldehyde (OPA) and a quaternary ammonia-glutaraldehyde solution (AG) for inactivating spores of Bacillus thuringiensis (BT), B. cereus (BC), and two strains of B. velezensis (BV1 and BV2). Spores of BV1 and BT were treated with 22.5 mg/m3 OPA by dry fumigation or 1 mg/mL AG by spray for 20 min, according to the manufacturer's recommendation. As no sporicidal effect was observed, OPA was tested at 112.5 mg/m3 for 40 min, showing effectiveness for BT but not for BV1. Minimum bactericidal concentration (MBC) tests revealed higher MBC values for glutaraldehyde, prompting an overnight test with 112.5 mg/m3 OPA by dry fumigation and 50 mg/mL AG by spray, using formaldehyde as a control. AG reduced all Bacillus strains, but with limited sporicidal effect. OPA was sporicidal for BT and BV1 but not for BC and BV2, indicating a strain-dependent effect. Formaldehyde performed better overall but did not completely inactivate BV2 spores. Our findings suggest that OPA and AG have potential as formaldehyde replacements in wet disinfection procedures.
Asunto(s)
Bacillus thuringiensis , Bacillus , Desinfectantes , Glutaral , Esporas Bacterianas , Desinfectantes/farmacología , Esporas Bacterianas/efectos de los fármacos , Bacillus/efectos de los fármacos , Bacillus/fisiología , Glutaral/farmacología , Bacillus thuringiensis/efectos de los fármacos , Bacillus thuringiensis/fisiología , Pruebas de Sensibilidad Microbiana , o-Ftalaldehído/farmacología , Bacillus cereus/efectos de los fármacos , Viabilidad Microbiana/efectos de los fármacos , Desinfección/métodosRESUMEN
Resource islands are vegetative formations in arid and semi-arid ecosystems that harbor microorganisms facing extreme conditions. However, there is a limitation in the knowledge of the agricultural biotechnological potential of microorganisms present in these islands. This study aimed to determine the capacity of Bacillus velezensis C3-3 and Cytobacillus sp. T106 isolates from resource islands to promote plant growth and control the phytopathogen Rhizoctonia solani. The bacteria were sequenced, and both grew at 50 °C, resisted 5% NaCl, withstood UV exposure, and grew in extreme pH conditions. Sixty-six genes in C3-3 and 71 in T106 were identified associated with plant growth promotion, and C3-3 was shown to promote leaf growth in lettuce plants. This promotional effect was associated with the production of indole-3-acetic acid (IAA), phosphorus solubilization, and the presence of genes related to the assimilation of rhizosphere exudates. Both strains inhibited R. solani through the production of volatile compounds and antagonism. Forty-five and 40 of these genes in C3-3 and T106, respectively, were associated with the production of proteases, lipases, siderophores, antimicrobial compounds, degradation enzymes, and secretion systems. Notably, Cytobacillus sp. has not been previously reported as a biocontrol agent. This work contributes to the evidence of the biotechnological potential of semi-arid region bacteria, offering prospects for improving agricultural production in areas with limiting conditions.
Asunto(s)
Bacillus , Microbiología del Suelo , Bacillus/genética , Bacillus/metabolismo , Bacillus/aislamiento & purificación , Rhizoctonia/genética , Rhizoctonia/crecimiento & desarrollo , Rizosfera , Enfermedades de las Plantas/microbiología , Agricultura , Lactuca/microbiología , Biotecnología/métodos , Islas , Ácidos IndolacéticosRESUMEN
Peanut production could be increased through plant growth-promoting rhizobacteria (PGPR). In this regard, the present field research aimed at elucidating the impact of PGPR on peanut yield, soil enzyme activity, microbial diversity, and structure. Three PGPR strains (Bacillus velezensis, RI3; Bacillus velezensis, SC6; Pseudomonas psychrophila, P10) were evaluated, along with Bradyrhizobium japonicum (BJ), taken as a control. PGPR increased seed yield by 8%, improving the radiation use efficiency (4-14%). PGPR modified soil enzymes (fluorescein diacetate activity by 17% and dehydrogenase activity by 28%) and microbial abundance (12%). However, PGPR did not significantly alter microbial diversity; nonetheless, it modified the relative abundance of key phyla (Actinobacteria > Proteobacteria > Firmicutes) and genera (Bacillus > Arthrobacter > Pseudomonas). PGPRs modified the relative abundance of genes associated with N-fixation and nitrification while increasing genes related to N-assimilation and N-availability. PGPR improved agronomic traits without altering rhizosphere diversity.
Asunto(s)
Arachis , Bacillus , Bradyrhizobium , Metagenómica , Pseudomonas , Rizosfera , Microbiología del Suelo , Suelo , Arachis/microbiología , Arachis/crecimiento & desarrollo , Arachis/metabolismo , Arachis/genética , Bacillus/genética , Bacillus/metabolismo , Bradyrhizobium/genética , Bradyrhizobium/metabolismo , Bradyrhizobium/crecimiento & desarrollo , Bradyrhizobium/fisiología , Pseudomonas/genética , Pseudomonas/fisiología , Pseudomonas/crecimiento & desarrollo , Suelo/química , Producción de Cultivos/métodos , Bacterias/genética , Bacterias/clasificación , Bacterias/metabolismo , Bacterias/enzimología , Bacterias/aislamiento & purificación , Biodiversidad , Fijación del Nitrógeno , Raíces de Plantas/microbiología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismoRESUMEN
Zearalenone (ZEA) is a mycotoxin produced by Fusarium species, and cause contamination of food and feed, with impacts in animal production and in food production chain. Effective detoxifying methods, such as biodegradation, are therefore required. This study aimed to isolate microorganisms and screen ZEA detoxifying strains. As a result, 197 microorganisms were isolated, and six were initially selected after colorimetric screening. ZEA (1 µg/mL) was added to culture media, and after 24 h, all six microorganisms were able to degrade ZEA, without the formation of α-ZOL. One isolate eliminated ~ 99% of ZEA and was identified as Bacillus velezensis CL197. ZEA metabolites produced by the bacteria were evaluated, and no metabolites with greater or similar toxicity than ZEA were detected. This strain was applied to swine in vitro digestion, and up to 64% of ZEA was degraded. B. velezensis CL197 significantly degraded ZEA, demonstrating potential to be used as a detoxifying agent in the food production chain as a biocontrol agent.
Asunto(s)
Bacillus , Triticum , Zearalenona , Zearalenona/metabolismo , Bacillus/metabolismo , Triticum/microbiología , Animales , Porcinos , Alimentación Animal/análisis , Alimentación Animal/microbiologíaRESUMEN
Probiotics are live microorganisms that, when administered in adequate quantities, provide health benefits to the host. In this study, phenotypic and genotypic methods were used to evaluate the probiotic properties of Bacillus altitudinis 1.4. The isolate was sensitive to all antimicrobials tested and presented a positive result in the hemolysis test. B. altitudinis 1.4 spores were more resistant than vegetative cells, when evaluated in simulation of cell viability in the gastrointestinal tract, as well as adhesion to the intestinal mucosa. The isolate was capable of self-aggregation and coaggregation with pathogens such as Escherichia coli ATCC 25922 and Salmonella Enteritidis ATCC 13076. Genomic analysis revealed the presence of genes with probiotic characteristics. From this study it was possible to evaluate the gene expression of pro-inflammatory and anti-inflammatory cytokines for different treatments. Viable vegetative cells of B. altitudinis 1.4 increased the transcription of pro-inflammatory factors, in addition to also increasing the transcription of IL-10, indicating a tendency to stimulate a pro-inflammatory profile. Given the results presented, B. altitudinis 1.4 showed potential to be applied in the incorporation of this microorganism into animal feed, since the spores could tolerate the feed handling and pelletization processes.
Asunto(s)
Bacillus , Genoma Bacteriano , Probióticos , Probióticos/farmacología , Bacillus/genética , Factores Inmunológicos/farmacología , Citocinas/metabolismo , Citocinas/genética , Escherichia coli/genética , Esporas Bacterianas/genética , Adhesión Bacteriana , Salmonella enteritidis/genética , Alimentación Animal/microbiología , Antibacterianos/farmacología , AnimalesRESUMEN
Gelatin, a versatile protein derived from collagen, is widely used in the food, pharmaceutical and medical sectors. However, bacterial contamination by spore-forming bacteria during gelatin processing represents a significant concern for product safety and quality. In this study, an investigation was carried out to explore the heat and chemical resistance, as well as the identification and characterization of spore-forming bacteria isolated from gelatin processing. The methodologies involved chemical resistance tests with drastic pH in microplates and thermal resistance tests in capillary tubes of various isolates obtained at different processing stages. In addition, phenotypic and genotypic analyses were carried out to characterize the most resistant isolates of spore-forming bacteria. The findings of this study revealed the presence of several species, including Bacillus cereus, Bacillus licheniformis, Bacillus sonorensis, Bacillus subtilis, Geobacillus stearothermophilus, and Clostridium sporogenes, with some isolates exhibiting remarkable chemical and heat resistances. In addition, a significant proportion of the most resistant isolates showed gelatinase activity (n = 19/21; 90.5 %) and the presence of heat resistance (n = 5/21; 23.8 %), and virulence genes (n = 11/21; 52.4 %). The results of this study suggest that interventions should be done in quality control practices and that process parameter adjustments and effective contamination reduction strategies should be implemented through gelatin processing.
Asunto(s)
Gelatina , Calor , ARN Ribosómico 16S , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Esporas Bacterianas , Esporas Bacterianas/genética , ARN Ribosómico 16S/genética , Virulencia/genética , Microbiología de Alimentos , Bacillus/genética , Bacillus/aislamiento & purificaciónRESUMEN
The drought can cause a decrease in food production and loss of biodiversity. In northern Mexico, an arid region, the chiltepin grows as a semi-domesticated crop that has been affected in its productivity and yield. An alternative to mitigate the effect of drought and aid in its conservation could be using Plant Growth-Promoting Bacteria (PGPB). The present study evaluated the capacity of native Bacillus spp., isolated from arid soils, as PGPBs and drought stress tolerance inducers in chiltepin under controlled conditions. Chiltepin seeds and seedlings were inoculated with native strains of Bacillus spp. isolated from arid soils, evaluating germination, vegetative, and drought stress tolerance parameters. The PGPBs improved vegetative parameters such as height, stem diameter, root length, and slenderness index in vitro. B. cereus (Bc25-7) improved in vitro survival of stressed seedlings by 68% at -1.02 MPa. Under greenhouse conditions, seedlings treated with PGPBs exhibited increases in root length (9.6%), stem diameter (13.68%), leaf fresh weight (69.87%), and chlorophyll content (38.15%). Bc25-7 alleviated severe water stress symptoms (7 days of water retention stress), and isolates B. thuringiensis (Bt24-4) and B. cereus (Bc25-7, and Bc30-2) increased Relative Water Content (RWC) by 51%. Additionally, the treated seeds showed improved germination parameters with a 46.42% increase in Germination Rate (GR). These findings suggest that using PGPBs could be an alternative to mitigate the effect of drought on chiltepin.
Asunto(s)
Bacillus , Capsicum , Sequías , Plantones , Capsicum/crecimiento & desarrollo , Capsicum/microbiología , Capsicum/fisiología , Bacillus/fisiología , Plantones/crecimiento & desarrollo , Plantones/microbiología , Estrés Fisiológico , Germinación , Semillas/crecimiento & desarrollo , Semillas/microbiología , Microbiología del Suelo , Raíces de Plantas/microbiología , Raíces de Plantas/crecimiento & desarrollo , MéxicoRESUMEN
The present study evaluated the capacity of three Bacillus species to improve health status and growth performance of Nile Tilapia fed with high levels of soybean meal and challenged with Aeromonas hydrophila. In vitro experiments showed that ß-hemolysin and metalloprotease enzymes were produced by A. hydrophila throughout the exponential growth phase. In vivo experiments showed that 107 colony-forming units (CFUs)/ml of this pathogen killed 50% of control group fishes in 13 days. To evaluate the influence of Bacillus strains on health status and growth performance in Nile Tilapia, 180 fishes (33.44 + 0.05 g) were distributed in 12 tanks of 200 L each, and animals were fed twice per day until satiety. 1) Control group without Bacillus, 2) Bacillus sp1, 3) Bacillus sp2, and 4) Bacillus sp3 groups were formulated containing 106 CFU/g. After 40 days of feeding, the fishes were intraperitoneally injected with 1 ml of A. hydrophila at 2 × 107 CFU/ml, and mortality was recorded. The results showed that cumulative mortality rate was significantly (p< 0.05) lower in the Bacillus sp1 (25%), sp2 (5%), and sp3 (15%) groups, than the control group (50%). Weight gain was also significantly better (p< 0.05) in the Bacillus sp1 (36%), sp2 (67%), and sp3 (55%) groups with respect to the control group (30%). In conclusion, functional diet formulated with high levels of soybean meal and supplemented with Bacillus sp2 could be an alternative to protect Nile tilapia cultures from A. hydrophila infections and improve fish growth performance.
Asunto(s)
Aeromonas hydrophila , Bacillus , Cíclidos , Enfermedades de los Peces , Infecciones por Bacterias Gramnegativas , Animales , Enfermedades de los Peces/microbiología , Enfermedades de los Peces/prevención & control , Cíclidos/crecimiento & desarrollo , Cíclidos/microbiología , Aeromonas hydrophila/patogenicidad , Aeromonas hydrophila/crecimiento & desarrollo , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/veterinaria , Infecciones por Bacterias Gramnegativas/prevención & control , Alimentación Animal , Probióticos/administración & dosificación , Glycine max/microbiología , AcuiculturaRESUMEN
In the present work, we carried out a comparative genomic analysis to trace the evolutionary trajectory of the bacterial species that make up the Liquorilactobacillus genus, from the identification of genes and speciation/adaptation mechanisms in their unique characteristics to the identification of the pattern grouping these species. We present phylogenetic relationships between Liquorilactobacillus and related taxa such as Bacillus, basal lactobacilli and Ligilactobacillus, highlighting evolutionary divergences and lifestyle transitions across different taxa. The species of this genus share a core genome of 1023 genes, distributed in all COGs, which made it possible to characterize it as Liquorilactobacillus sensu lato: few amino acid auxotrophy, low genes number for resistance to antibiotics and general and specific cellular reprogramming mechanisms for environmental responses. These species were divided into four clades, with diversity being enhanced mainly by the diversity of genes involved in sugar metabolism. Clade 1 presented lower (< 70%) average amino acid identity with the other clades, with exclusive or absent genes, and greater distance in the genome compared to clades 2, 3 and 4. The data pointed to an ancestor of clades 2, 3 and 4 as being the origin of the genus Ligilactobacillus, while the species of clade 1 being closer to the ancestral Bacillus. All these traits indicated that the species of clade 1 could be soon separated in a distinct genus.
Asunto(s)
Fermentación , Genoma Bacteriano , Filogenia , Adaptación Fisiológica/genética , Evolución Molecular , Bacillus/genética , Bacillus/metabolismoRESUMEN
Improper electronic waste management in the world especially in developing countries such as Iran has resulted in environmental pollution. Copper, nickel, and manganese are from the most concerned soil contaminating heavy metals which found in many electronic devices that are not properly processed. The aim of this study was to investigate the biological removal of copper, nickel, and manganese by Bacillus species isolated from a landfill of electronic waste (Zainal Pass hills located in Isfahan, Iran) which is the and to produce nanoparticles from the studied metals by the isolated bacteria. The amounts of copper, nickel, and manganese in the soil was measured as 1.9 × 104 mg/kg, 0.011 × 104 mg/kg and 0.013 × 104 mg/kg, respectively based on ICP-OES analysis, which was significantly higher than normal (0.02 mg/kg, 0.05 mg/kg, and 2 mg/kg, respectively. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of metals on the bacterial isolates was determined. The biosorption of metals by the bacteria was evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES). The metal nanoparticles were synthetized utilizing the isolates in culture media containing the heavy metals with the concentrations to which the isolates had shown resistance. X ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used for the evaluation of the fabrication of the produced metal nanoparticles. Based on the findings of this study, a total of 15 bacterial isolates were obtained from the soil samples. The obtained MICs of copper, nickel, and manganese on the isolates were 40-300 mM, 4-10 mM, and 60-120 mM, respectively. The most resistant isolates to copper were FM1 and FM2 which were able to bio-remove 79.81% and 68.69% of the metal, respectively. FM4 and FM5 were respectively the most resistant isolate to nickel and manganese and were able to bio-remove 86.74% and 91.96% of the metals, respectively. FM1, FM2, FM4, and FM5 was molecularly identified as Bacillus cereus, Bacillus thuringiensis, Bacillus paramycoides, and Bacillus wiedmannii, respectively. The results of XRD, SEM and EDS showed conversion of the copper and manganese into spherical and oval nanoparticles with the approximate sizes of 20-40 nm. Due to the fact that the novel strains in this study showed high resistance to copper, nickel, and manganese and high adsorption of the metals, they can be used in the future, as suitable strains for the bio-removal of these metals from electronic and other industrial wastes.
Asunto(s)
Bacillus , Cobre , Residuos Electrónicos , Manganeso , Nanopartículas del Metal , Níquel , Microbiología del Suelo , Contaminantes del Suelo , Níquel/metabolismo , Níquel/química , Cobre/metabolismo , Bacillus/metabolismo , Bacillus/aislamiento & purificación , Bacillus/clasificación , Contaminantes del Suelo/metabolismo , Nanopartículas del Metal/química , Manganeso/metabolismo , Pruebas de Sensibilidad Microbiana , Irán , Biodegradación Ambiental , Suelo/química , Metales Pesados/metabolismoRESUMEN
Probiotic microorganisms can stimulate an immune response and increase the efficiency of vaccines. For example, Bacillus toyonensis is a nonpathogenic, Gram-positive bacterium that has been used as a probiotic in animal supplementation. It induces immunomodulatory effects and increases the vaccine response in several species. This study aimed to evaluate the effect of B. toyonensis supplementation on the modulation of the immune response in horses vaccinated with recombinant Clostridium tetani toxin. Twenty horses were vaccinated twice, with an interval of 21 days between doses, and equally divided into two groups: the first group was supplemented orally for 42 days with feed containing viable spores of B. toyonensis (1 × 108) mixed with molasses (40 ml), starting 7 days before the first vaccination; the second (control) group received only feed mixed with molasses, starting 7 days before the first vaccination. Serum samples were collected to evaluate the humoral immune response using an in-house indirect enzyme-linked immunosorbent assay (ELISA), and peripheral blood mononuclear cells (PBMCs) were collected to evaluate cytokine transcription (qPCR). For the specific IgG-anti-rTENT titer, the supplemented group had ELISA values that were four times higher than those of the control group (p < 0.05). The supplemented group also showed higher ELISA values for the IgGa and IgGT sub-isotypes compared to the control group. In PBMCs stimulated with B. toyonensis, relative cytokine transcription of the supplemented group showed 15-, 8-, 7-, and 6-fold increases for IL1, TNFα, IL10 and IL4, respectively. When stimulated with a vaccine antigen, the supplemented group showed 1.6-, 1.8-, and 0.5-fold increases in IL1, TNFα, and IL4, respectively, compared to the control group. Horses supplemented with B. toyonensis had a significantly improved vaccine immune response compared to those in the control group, which suggests a promising approach for improving vaccine efficacy with probiotics.
Asunto(s)
Bacillus , Enfermedades de los Caballos , Probióticos , Animales , Caballos/inmunología , Bacillus/inmunología , Probióticos/administración & dosificación , Probióticos/farmacología , Enfermedades de los Caballos/prevención & control , Enfermedades de los Caballos/inmunología , Enfermedades de los Caballos/microbiología , Tétanos/prevención & control , Tétanos/inmunología , Toxoide Tetánico/inmunología , Toxoide Tetánico/administración & dosificación , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/administración & dosificación , Masculino , Alimentación Animal , Femenino , Dieta/veterinaria , Citocinas/metabolismoRESUMEN
Soybean is the main oilseed cultivated worldwide. Even though Brazil is the world's largest producer and exporter of soybean, its production is severely limited by biotic factors. Soil borne diseases are the most damaging biotic stressors since they significantly reduce yield and are challenging to manage. In this context, the present study aimed to evaluate the potential of a bacterial strain (Ag109) as a biocontrol agent for different soil pathogens (nematodes and fungi) of soybean. In addition, the genome of Ag109 was wholly sequenced and genes related to secondary metabolite production and plant growth promotion were mined. Ag109 showed nematode control in soybean and controlled 69 and 45% of the populations of Meloidogyne javanica and Pratylenchus brachyurus, respectively. Regarding antifungal activity, these strains showed activity against Macrophomia phaseolina, Rhizoctonia solani, and Sclerotinia sclerotiorum. For S. sclerotiorum, this strain increased the number of healthy plants and root dry mass compared to the control (with inoculation). Based on the average nucleotide identity and digital DNA-DNA hybridization, this strain was identified as Bacillus velezensis. Diverse clusters of specific genes related to secondary metabolite biosynthesis and root growth promotion were identified, highlighting the potential of this strain to be used as a multifunctional microbial inoculant that acts as a biological control agent while promoting plant growth in soybean.
Asunto(s)
Ascomicetos , Bacillus , Genoma Bacteriano , Glycine max , Enfermedades de las Plantas , Animales , Bacillus/genética , Glycine max/microbiología , Glycine max/parasitología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitología , Enfermedades de las Plantas/prevención & control , Genoma Bacteriano/genética , Ascomicetos/genética , Rhizoctonia/genética , Control Biológico de Vectores , Agentes de Control Biológico , Secuenciación Completa del Genoma , Tylenchoidea , Filogenia , Antibiosis , BrasilRESUMEN
Industrialization has brought many environmental problems since its expansion, including heavy metal contamination in water used for agricultural irrigation. This research uses microbial fuel cell technology to generate bioelectricity and remove arsenic, copper, and iron, using contaminated agricultural water as a substrate and Bacillus marisflavi as a biocatalyst. The results obtained for electrical potential and current were 0.798 V and 3.519 mA, respectively, on the sixth day of operation and the pH value was 6.54 with an EC equal to 198.72 mS/cm, with a removal of 99.08, 56.08, and 91.39% of the concentrations of As, Cu, and Fe, respectively, obtained in 72 h. Likewise, total nitrogen concentrations, organic carbon, loss on ignition, dissolved organic carbon, and chemical oxygen demand were reduced by 69.047, 86.922, 85.378, 88.458, and 90.771%, respectively. At the same time, the PDMAX shown was 376.20 ± 15.478 mW/cm2, with a calculated internal resistance of 42.550 ± 12.353 Ω. This technique presents an essential advance in overcoming existing technical barriers because the engineered microbial fuel cells are accessible and scalable. It will generate important value by naturally reducing toxic metals and electrical energy, producing electric currents in a sustainable and affordable way.
Asunto(s)
Bacillus , Fuentes de Energía Bioeléctrica , Fuentes de Energía Bioeléctrica/microbiología , Bacillus/metabolismo , Metales Pesados , Contaminantes Químicos del Agua/metabolismo , Cobre/química , Cobre/metabolismo , Concentración de Iones de Hidrógeno , Biodegradación Ambiental , Arsénico/metabolismoRESUMEN
Biosurfactants (BSFs) are molecules produced by microorganisms from various carbon sources, with applications in bioremediation and petroleum recovery. However, the production cost limits large-scale applications. This study optimized BSFs production by Bacillus velezensis (strain MO13) using residual glycerin as a substrate. The spherical quadratic central composite design (CCD) model was used to standardize carbon source concentration (30 g/L), temperature (34 °C), pH (7.2), stirring (239 rpm), and aeration (0.775 vvm) in a 5-L bioreactor. Maximum BSFs production reached 1527.6 mg/L of surfactins and 176.88 mg/L of iturins, a threefold increase through optimization. Microbial development, substrate consumption, concentration of BSFs, and surface tension were also evaluated on the bioprocess dynamics. Mass spectrometry Q-TOF-MS identified five surfactin and two iturin isoforms produced by B. velezensis MO13. This study demonstrates significant progress on BSF production using industrial waste as a microbial substrate, surpassing reported concentrations in the literature.
Asunto(s)
Bacillus , Glicerol , Lipopéptidos , Tensoactivos , Bacillus/metabolismo , Tensoactivos/metabolismo , Tensoactivos/química , Lipopéptidos/biosíntesis , Lipopéptidos/química , Glicerol/metabolismo , Reactores BiológicosRESUMEN
Bacterial contamination causes irreparable losses in the performance of alcoholic fermentation. Antibiotics are used to control these microorganisms, but they generate residues and cause microbial resistance. Today the only commercial product used by the mills is hops, but it is very expensive. As an alternative, the objective of this work was to evaluate the feasibility of using extracts from plants grown in the Cerrado for antimicrobial control during an alcoholic fermentation to replace antibiotics. Hydraethanolic extracts of leaves and essential oil of the following species were tested: Schinus terebinthifolius Raddi, Serjania erecta, Serjania marginata, Campomanesia adamantium and Syzygium cumini. Only the extract of Serjania marginata did not show any activity against the bacterium Bacillus sp. Both the essential oils as well as the hydroalcoholic extracts of S. terebinthifolius and C. adamantium and the extract of S. erecta showed antibacterial activity without harming the yeast, with potential to replace the hops.
Asunto(s)
Fermentación , Extractos Vegetales , Extractos Vegetales/farmacología , Antibacterianos/farmacología , Bacillus , Aceites Volátiles/farmacología , Pruebas de Sensibilidad Microbiana , Bacterias/efectos de los fármacosRESUMEN
The new technology of microbially induced calcium carbonate precipitation (MICP) has been applied in construction materials as a strategy to enhance their properties. In pursuit of solutions that are more localized and tailored to the study's target, this work focused on isolating and selecting bacteria capable of producing CaCO3 for posterior application in concrete aggregates. First, eleven bacterial isolates were obtained from aggregates and identified as genera Bacillus, Lysinibacillus, Exiguobacterium, and Micrococcus. Then, the strains were compared based on the quantity and nature of calcium carbonate they produced using thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy with energy dispersive spectroscopy. Bacillus sp. dominated the cultured isolates and, along with Lysinibacillus sp., exhibited the highest CaCO3 conversion (up to 80%). On the other hand, Exiguobacterium and Micrococcus genera showed the poor ability to MICP (21.3 and 20.3%, respectively). Calcite and vaterite were the dominant carbonate polymorphs, with varying proportions. Concrete aggregates have proven to be a source of microorganisms capable of producing stable calcium carbonates with a high conversion rate. This indicates the feasibility of using microorganisms derived from local sources for application in construction materials as a sustainable way to enhance their characteristics.
Asunto(s)
Carbonato de Calcio , Carbonato de Calcio/química , Bacterias/metabolismo , Bacillus/metabolismo , Materiales de Construcción/microbiología , Reciclaje , Microscopía Electrónica de Rastreo , Difracción de Rayos XRESUMEN
Modern crop production relies on the application of chemical pesticides and fertilizers causing environmental and economic challenges. In response, less environmentally impactful alternatives have emerged such as the use of beneficial microorganisms. These microorganisms, particularly plant growth-promoting bacteria (PGPB), have demonstrated their ability to enhance plant growth, protect against various stresses, and reduce the need for chemical inputs. Among the PGPB, Bacillus species have garnered attention due to their adaptability and commercial potential. Recent reports have highlighted Bacillus strains as biocontrol agents against phytopathogenic bacteria while concurrently promoting plant growth. We also examined Bacillus plant growth-promoting abilities in Arabidopsis thaliana seedlings. In this study, we assessed the potential of various Bacillus strains to control diverse phytopathogenic bacteria and inhibit quorum sensing using Chromobacterium violaceum as a model system. In conclusion, our results suggest that bacteria of the genus Bacillus hold significant potential for biotechnological applications. This includes developments aimed at reducing agrochemical use, promoting sustainable agriculture, and enhancing crop yield and protection.
Asunto(s)
Arabidopsis , Bacillus , Enfermedades de las Plantas , Bacillus/fisiología , Arabidopsis/microbiología , Arabidopsis/crecimiento & desarrollo , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología , Percepción de Quorum , Chromobacterium/fisiología , Chromobacterium/crecimiento & desarrollo , Agentes de Control Biológico/farmacología , Desarrollo de la Planta , Plantones/microbiología , Plantones/crecimiento & desarrollo , Microbiología del SueloRESUMEN
The study evaluated dietary supplementation with a feed additive composed of multi-strain Bacillus for Nile tilapia Oreochromis niloticus. In vitro and in vivo assays employing culture-based microbiological methods and metagenomics were performed. Additionally, the study assessed the haemato-immunology, intestinal microbiome, and growth performance of the animals. For this, 30 juvenile Nile tilapia were used in the in vitro assay and 180 (60 + 120) in the in vivo assays. In the in vitro assay, we found evidence of adhesion of the probiotic bacteria to the intestinal mucus of fish, corroborated in the 15-day in vivo assay, in which the count of B. licheniformis was significantly higher in fish fed with probiotic when compared to fish of the control group. Furthermore, in the 50-day in vivo trial, a metagenomic analysis provided evidence for the modulation of the intestine microbiome of Nile tilapia by dietary supplementation of the probiotic. In addition, there was an increase in species richness, higher abundance of potentially probiotic autochthonous species and a lower abundance of Aeromonas sp. when the animals were fed the supplemented diet. Finally, no significant differences were observed in growth performance and haemato-immunological analyses, suggesting no harm to fish health when the product was supplemented for 15 and 50 days. The in vitro results indicate that the multi-strain probiotics were able to adhere to the intestinal mucus of Nile tilapia. Additionally, a modulation of the intestinal microbiome was evidenced in the in vivo assay.