Inoculantes comerciales en Baja California, México: calidad y capacidad de biocontrol de hongos fitopatógenos

In the present study, the biological quality and cell viability of different microbial inoculants marketed in Baja California, Mexico, was carried out. For this purpose, the antagonistic capacity was determined in triplicate by means of dual confrontation with phytopathogenic fungi, determination of cell viability using the serial dilution technique in culture medium; as well as the review of compliance with the packaging criteria based on the Mexican regulations in the products: Bioben, T-22, Funqui, Agroderma, Bio-Tilis, Enerbac, Fus-Out and Bacillus 1537. The results showed that the products Agroderma, Bacillus 1537 and Fus-Out, no health registration submitted. On the other hand, the viability of the inoculants evaluated by means of the plate count technique, showed values ​​of CFU/g or CFU/mL, lower than those indicated by the labels of the commercial inoculants. The results of antagonism of biological fungi against phytopathogenic fungi: Alternaria alternata, Macrophomina sp., Fusarium solani, and Botrytis sp., showed that only the product formulated based on Bacillus 1537 presented an inhibitory effect greater than 50% on phytopathogens. evaluated. In contrast, the products formulated based on mycoparasitic fungi, showed a lower efficiency of inhibition of phytopathogenic fungi, being the Funqui inoculant, the one that presented the capacity to inhibit their growth by 50%. Finally, Baja California has a wide presence of commercial inoculants; however, its quality and biological efficiency is variable against the pathogens present in the agricultural soils of the region.En el presente estudio se realiza una evaluación de la calidad biológica y viabilidad celular de diferentes inoculantes microbianos comercializados en Baja California, México. Para tal fin, se determina por triplicado la capacidad antagónica mediante la confrontación dual con hongos fitopatógenos, la viabilidad celular usando la técnica de dilución en serie en medio de cultivo; así como la revisión del cumplimiento de los criterios de criterios de rotulación de etiqueta con base a la normativa mexicana en los productos: Bioben, T-22, Funqui, Agroderma, Bio-Tilis, Enerbac, Fus-Out y Bacillus 1537. Los resultados mostraron que los productos Agroderma, Bacillus 1537 y Fus-Out, no presentaron registro sanitario. Por otra parte, la viabilidad de los inoculantes evaluados mediante la técnica de conteo en placa, mostraron valores de UFC/g o UFC/mL, inferiores a los indicados por las etiquetas de los inoculantes comerciales. Los resultados de antagonismos de los productos biológicos contra los hongos fitopatógenos: Alternaria alternata, Macrophomina sp., Fusarium solani, y Botrytis sp., mostraron que solo el producto formulado a base de Bacillus 1537 presentó un efecto inhibitorio mayor del 50% sobre los hongos fitopatógenos evaluados. En contraste, los productos formulados a base de hongos mico-parásitos, mostraron una menor eficiencia de inhibición de hongos fitopatógenos, siendo el inoculante Funqui, el que presentó la capacidad de inhibir el crecimiento de estos en un 50%. Finalmente, Baja California cuenta con una amplia presencia de inoculantes comerciales; no obstante, su calidad y eficiencia biológica es variable contra los agentes patógenos presentes en los suelos agrícolas de la región

CRECIMIENTO, ACUMULACIÓN Y DISTRIBUCIÓN DE MATERIA SECA EN TOMATE DE INVERNADERO

Se realizó un estudio en el cultivo de tomate crecido en invernadero, con el objetivo de conocer su crecimiento y desarrollo, así como su partición y acumulación de materia seca durante su ciclo de crecimiento. Semanalmente se midió la altura, número de hojas y el área foliar de la hoja más recientemente madura. Adicionalmente, cada tres semanas se realizaron muestreos de biomasa a plantas completas y se les determinó el peso seco y su partición entre frutos y tejido foliar. Al final del estudio, la planta alcanzó una altura de 2,86 m, con una tasa máxima de crecimiento presentada entre los 165 y 175 días después del trasplante (ddt; 24 cm semana-1). La máxima área foliar en la hoja más recientemente madura se presentó entre los 30 y los 80 ddt (1500 cm2). Así mismo, cada planta acumuló 1003,4 g de materia seca, destinando 54% hacia los frutos y 46% hacia las hojas y tallos. El conocimiento detallado del crecimiento de plantas de tomate de invernadero brinda a los productores la oportunidad de diseñar prácticas de manejo que incrementen sus rendimientos a la vez que hacen eficiente la aplicación de recursos como el agua y los fertilizantes

BIOSINTESIS, ACUMULACIÓN Y EFECTO DEL AMBIENTE SOBRE COMPUESTOS ANTIOXIDANTES DEL FRUTO DEL CULTIVO DE CHILE (Capsicum spp.)/ BIOSYNTHESIS, ACCUMULATION AND EFFECT OF THE ENVIRONMENT ON ANTIOXIDANT COMPOUNDS IN THE FRUIT OF PEPPER CROP (Capsicum spp.)

El fruto del chile (Capsicum spp) es uno de los productos agrícolas alimenticios más populares que existe en el mundo. Posee diversos usos y formas que han sido utilizados desde tiempos muy remotos. Por su nivel de consumo el fruto del chile figura como uno de las Solanáceas más importantes. Un interés creciente ha resurgido en estudiar sus propiedades químico-alimenticias, ya que contiene grandes cantidades de compuestos antioxidantes de gran importancia en la prevención de enfermedades crónicas y degenerativas. Entre estos compuestos se encuentran los carotenoides, el ácido ascórbico y los capsaicinoides. Sin embargo, la cantidad de estos compuestos, varía notablemente entre especies de Capsicum e incluso entre variedades. La edad del fruto a la cosecha, el ambiente de desarrollo de la planta, manejo agronómico y vida post-cosecha, son algunos de los factores que influyen en los contenidos y concentraciones de estos compuestos en el fruto del chile. La presente revisión se realizó con el objetivo de explorar aspectos importantes sobre la biosíntesis, acumulación y efecto del ambiente sobre los contenidos de compuestos antioxidantes en frutos del cultivo de chile. ABSTRACT The pepper fruit (Capsicum spp.) is one of the most popular nutritional agricultural products in the world. It has a diversity of uses and presentations since remote times. Due to its consumption level, the pepper fruit appears like one of the most important member of the Solanaceae family. The high amount of antioxidant compounds present resulted in a recent resurging interest in studying its nutritional and chemical properties for the prevention of chronic and degenerative diseases. These compounds include carotenoids, ascorbic acid and capsaicinoids. However, the amount of these compounds is remarkably variable among Capsicum species and even between varieties. The fruit age at harvest time, environmental conditions during the plant growth, agronomic management and post-harvest handling, are some of the factors that infl uence contents and concentrations of these compounds in pepper fruit. This review aims on exploring important aspects of the biosynthesis, accumulation and environment eff ect on contents of antioxidant compounds in pepper fruit

Efectos de cadmio en compuestos fenolicos totales y flavonoides de Euglena gracilis

In the present study the production of phenolic acids and flavonoid compounds by E. gracilis exposed to two cadmium concentrations (0.02 and 0.14 mM) was evaluated using high-performance liquid chromatography (HPLC). The results showed that E. gracilis exposed to 0.02 mM Cd+2 increased significantly the total content of phenolic compounds (798.46 ± 12.61 ?g GA/g) and total flavonoids (241.34 ± 47.63 ?g QE/g) with respect to the control (137.34 ± 19.80 ?g QE/g DW and 549.00 ± 8.57 ?g GA/g DW, respectively). However, no significant increase in the total content of phenolic compounds (568.54 ± 17.42 ?g GA/g DW) and total flavonoids (141.11 ± 9.36 ?g QE/g DW) were observed in E. gracilis exposed to 0.14 mM Cd+2. Further research is necessary to determine the specific role of flavonoids in E. gracilis exposed to high concentrations of Cd+2.En el presente estudio la producción de compuestos fenolicos y flavonoides producidos por E. gracilis expuesto a dos concentraciones de cadmio fue evaluado usando cromatografía liquida de alta precisión (HPLC). Los resultados mostraron que 0.02 mM de Cd+2 incrementaba significativamente el contenido total de compuestos fenolicos (798.46 ± 12.61 ?g GA/g) y flavonoides (241.34 ± 47.63 ?g QE/g) con respecto al control (137.34 ± 19.80 ?g QE/g DW y 549.00 ± 8.57 ?g GA/g DW) respectivamente. Sin embargo, incrementos no significativos en el contenido de compuestos fenolicos (568.54 ± 17.42 ?g GA/g DW) y flavonoides totales (141.11 ± 9.36 ?g QE/g DW) fueron observados en E. gracilis expuestas a 0.14 mM de Cd+2. Futuros estudios son necesarios para determinar la función especifica de los flavonoides en E. gracilis expuesto a altas concentraciones de Cd+2

Inhibition of Fusarium solani in transgenic insect-resistant cotton plants treated with silver nanoparticles from Prosopis glandulosa and Pluchea sericea

Abstract The phytosynthesis of nanoparticles is a green chemistry approach that combines nanotechnology and bioactive compounds of plants. The aim of this study was to evaluate the effect of silver nanoparticles (AgNPs) from Prosopis glandulosa and Pluchea sericea, respectively, on the control of Fusarium solani previously inoculated in the rhizosphere of transgenic insect-resistant cotton plants. The results showed that the weekly application of AgNPs from P. glandulosa and P. sericea caused a diminution of fungal propagules in the soil after 30 days of treatment. In this sense, the AgNPs from P. glandulosa were more efficient in the reduction of infection points in the roots of the plants infected with F. solani compared with AgNPs from P. sericea. Additionally, the application of AgNPs from both plants showed a significant increase of optimum quantum yield (Fv/Fm), stomata conductance (gs), and the number of lateral roots in transgenic insect-resistant cotton plants after 30 days of exposure when compared to the control. Based on our results, AgNPs from P. glandulosa and P. sericea could inhibit growth of Fusarium solani. However, more extensive and elaborate studies are needed to explain the different mechanisms that participate in the inhibition of growth of fungus using nanoparticles from these plants

Changes in the phenylalanine ammonia lyase activity, total phenolic compounds, and flavonoids in Prosopis glandulosa treated with cadmium and copper

ABSTRACT The aim of the present work is to evaluate the changes on the phenylalanine ammonia lyase (PAL) activity, phenolic compounds accumulation and photochemical efficiency in leaves of P. glandulosa treated with Cd2+ (0.001 M) and Cu2+ (0.52 M) concentrations for 96 h under hydroponic conditions. The results showed that only leaves treated with copper had a decrease in photochemical efficiency and leaf epidermal polyphenols in P. glandulosa leaves after 96 h of exposure. On the other hand the reverse-phase HPLC analysis revealed higher levels of phenolic compound (gallic, vanillic and caffeic acids) and flavonoids (rutin and kaempferol-3-O-glucosides) in plant leaves from Cu and Cd-treatments with respect to control plants. Finally, highest increments in PAL activity was observed in extracts of leaves treated with Cu and Cd (about 205 and 284%), respectively, with respect to control plants after 96 h treatment. These suggest that activation of phenylpropanoid pathway represent a source of nonenzymatic antioxidants that protect at P. glandulosa against oxidative stress when exposed to cadmium and copper. Hence future studies are necessary to elucidate the participation of phenylpropanoid pathway in the reduction of metal toxicity in Prosopis species

Silver nanoparticles from Prosopis glandulosa and their potential application as biocontrol of Acinetobacter calcoaceticus and Bacillus cereus

In the present study the characterization and properties of silver nanoparticles from Prosopis glandulosa leaf extract (AgNPs) were investigated using UV–Vis spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The UV–Vis spectroscopic analysis showed the absorbance peaked at 487 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had Z-average diameter of 421 nm with higher stability (−200 mV). The EDS analysis also exhibited presentation of silver element. Additionally, the different concentrations of AgNPs (25, 50, 75 and 100 mg/mL) showed antibacterial activity against Acinetobacter calcoaceticus and Bacillus cereus. Finally, AgNPs from leaf extracts of P. glandulosa may be used as an agent of biocontrol of microorganism of importance medical. However, further studies will be needed to fully understand the antimicrobial activity of silver nanoparticles obtain from P. glandulosa

Keratinases from <i>Streptomyces netropsis</i> and <i>Bacillus subtilis</i> and Their Potential Use in the Chicken Feather Degrading

Feathers are the most prevalent agricultural waste generated by chicken farms, polluting the environment and wasting protein resources as a result of the accumulation of large amounts of feathers. Therefore, keratinase-producing microorganisms represent a promising potential technique for the degradation of feather waste. Streptomyces netropsis A-ICA and Bacillus subtilis ALICA, previously isolated from the rhizosphere of desert plants (Larrea tridentata and Prosopis juliflora) respectively, were assessed for their feather-degradation ability. Keratinase activity was optimized using various parameters, including incubation time, pH, temperature, and feather concentration. The maximum keratinase activity of S. netropsis A-ICA and B. subtilis ALICA (113.6 ± 5.1 and 135.6 ± 4.1 U/mL) was obtained at the 5th and 3rd day of incubation with initial pH of 7.0 and 7.5 at 25 and 30 °C, and 1% (w/v) of chicken feather, respectively. Under the optimized conditions, the concentration of soluble protein in the feather hydrolysate reached 423.3 ± 25 and 565.3 ± 7.7 µg/mL, with feathers weight loss of 84 ± 2 and 86± 1.5% by S. netropsis A-ICA and B. subtilis ALICA, respectively. The highest disulphide bond reductase activity reached 10.7 ± 0.4 and 1.96 ± 1.1 U/mL, after five and three days of inoculation with S. netropsis A-ICA and B. subtilis ALICA, respectively. Furthermore, the antioxidant activity of feather protein hydrolysate obtained by S. netropsis A-ICA and B. subtilis ALICA was evaluated using DPPH radical-scavenging activity, which exhibited a significant antioxidant potential with an IC50 value of 0.8 and 0.6 mg/mL. The 3D models of detected keratinases in both strains showed high similarity with subtilisin family. Further, the docking results clarified the importance of GSG and VVVFTP domains in B. subtilis and beta-keratin, respectively. The present study revealed the keratinolytic potential of S. netropsis A-ICA and B. subtilis ALICA in chicken feather degradation, which have potential application value and may be exploited as supplementary protein and antioxidant in animal feed formulations

Keratinases from Streptomyces netropsis and Bacillus subtilis and Their Potential Use in the Chicken Feather Degrading

Feathers are the most prevalent agricultural waste generated by chicken farms, polluting the environment and wasting protein resources as a result of the accumulation of large amounts of feathers. Therefore, keratinase-producing microorganisms represent a promising potential technique for the degradation of feather waste. Streptomyces netropsis A-ICA and Bacillus subtilis ALICA, previously isolated from the rhizosphere of desert plants (Larrea tridentata and Prosopis juliflora) respectively, were assessed for their feather-degradation ability. Keratinase activity was optimized using various parameters, including incubation time, pH, temperature, and feather concentration. The maximum keratinase activity of S. netropsis A-ICA and B. subtilis ALICA (113.6 &plusmn; 5.1 and 135.6 &plusmn; 4.1 U/mL) was obtained at the 5th and 3rd day of incubation with initial pH of 7.0 and 7.5 at 25 and 30 &deg;C, and 1% (w/v) of chicken feather, respectively. Under the optimized conditions, the concentration of soluble protein in the feather hydrolysate reached 423.3 &plusmn; 25 and 565.3 &plusmn; 7.7 &micro;g/mL, with feathers weight loss of 84 &plusmn; 2 and 86&plusmn; 1.5% by S. netropsis A-ICA and B. subtilis ALICA, respectively. The highest disulphide bond reductase activity reached 10.7 &plusmn; 0.4 and 1.96 &plusmn; 1.1 U/mL, after five and three days of inoculation with S. netropsis A-ICA and B. subtilis ALICA, respectively. Furthermore, the antioxidant activity of feather protein hydrolysate obtained by S. netropsis A-ICA and B. subtilis ALICA was evaluated using DPPH radical-scavenging activity, which exhibited a significant antioxidant potential with an IC50 value of 0.8 and 0.6 mg/mL. The 3D models of detected keratinases in both strains showed high similarity with subtilisin family. Further, the docking results clarified the importance of GSG and VVVFTP domains in B. subtilis and beta-keratin, respectively. The present study revealed the keratinolytic potential of S. netropsis A-ICA and B. subtilis ALICA in chicken feather degradation, which have potential application value and may be exploited as supplementary protein and antioxidant in animal feed formulations

Bioaccumulation and effect of cadmium in the photosynthetic apparatus of Prosopis juliflora

In the present study Prosopis juliflora plants grown in hydroponics solution were exposed to 50,100 and 1000 μM CdCl2. The cadmium uptake, transport and toxicity on the photosynthetic activities in the plants were measured at 48 h after starting cadmium treatments. The results showed that the concentration of Cd2+ in P. juliflora tended to increase with addition of Cd2+ to hydroponics solution. However, the increase of Cd2+ in roots and leaves varied largely. In this sense, the accumulation of Cd2+ in P. juliflora roots increased significantly in proportion with the addition of this metal. In contrast a relatively low level of Cd2+ transportation index, and bioaccumulation factor were found in P. juliflora at 48 h after of treatments. On the other hand the maximum photochemical efficiency of photosystem II (Fv/Fm) and the activity of photosystem II (Fv/Fo) ratios in P. juliflora leaf treated with Cd2+ not showed significantly changes during the experiment. These results suggested that the photosynthetic apparatus of P. juliflora was not the primary target of the Cd2+ action. Further studies will be focused in understanding the participation of the root system in Prosopis plants with the rhizosphere activation and root adsorption to soil Cd2+ under natural conditions