Biofertilizers are microorganisms that enhance the productivity and health of crops, help nitrogen fixation, solubilize phosphates, produce siderophores and phytohormones. There is a large community of microorganisms that help fertilize the soil, one of them being the genus Azotobacter. The aim of the present research is the evaluation of parameters for potential production of Azotobacter sp on a large scale. 15 soil samples from the Rioja province in San Martin, Peru, were processed for Azotobacter isolation and nitrogen fixing capacity, phytohormone production and phosphate solubilization index were measured. The best growth promoting strain was cultured in batch conditions to evaluate production parameters. Out of the 18 Azotobacter strains isolated, 1I and 1F showed the best results for nitrogen fixation with 2.0496 mgL-1, 1.428 mgL-1, respectively; the 1F strain had the highest phyt...

Los biofertilizantes son microorganismos que aumentan la productividad y sanidad de los cultivos, ayudan a fijar nitrógeno, solubilizar fosfatos, producción de sideróforos y fitohormonas. Existe una gran población de microorganismos que ayudan a fertilizar los suelos, entre ellos el género Azotobacter. La presente investigación tuvo como objetivo la evaluación de parámetros para una producción potencial de Azotobacter sp a gran escala. Se procesaron un total de 15 muestras de suelos provenientes de la provincia de Rioja, región de San Martín, Perú, para el aislamiento de bacterias del género Azotobacter y se midieron las capacidades de fijación de nitrógeno, producción de fitohormonas e índice de solubilización de fosfatos. La mejor cepa promotora de crecimiento fue cultivada en condiciones batch para evaluar los parámetros de producción. Se aislaron 18 cepas correspo...

The objective of the research was to evaluate the effect of the azotobacter-rhizobium biofertilizerin Lupinus mutabilisSweet “tarwi”, as an alternative to chemical fertilization. Rhizobium sp and Azotobacter sp. strains were isolated from bean nodules and agricultural lands of the UNALM (Universidad Nacional Agraria La Molina). After a selection, they were for-mulated and applied as bacterial biofertilizers in seeds and seedlings of tarwi. Results at laboratory level showed the best treatment with Azotobacter sp. with 70% germination, superior to the water treatment (negative control) with 42% of ger-mination. In addition, the dry biomass after treatment with Rizo 1 strain (Rhizobium sp.) was superior to potassium nitrate (N +) after 20 days of evaluation. At the greenhouse level, there were statistically significant differences in the root length (LR) parameter between the Azotobact...

La investigación tuvo como objetivo evaluar el efecto del biofertilizante azotobacter-rhizobium en Lupinus mutabilis Sweet “tarwi”, como alternativa a la fertilización química. Se aislaron cepas de Rhizobium sp y Azotobacter sp a nivel de laboratorio e invernadero a partir de nódulos de frijol y tierras agrícolas de la UNALM (Universidad Nacional Agraria La Molina). Luego de una selección se formularon y aplicaron como biofertilizantes bacterianos en semillas y plántulas de tarwi. Los resultados a nivel de laboratorio mostraron el mejor tratamiento con Azotobacter sp. con 70% de germinación, superior al tratamiento solo con agua (control negativo) en el cual se obtuvo 42% de germinación. Además, la biomasa seca después del tratamiento con la cepa Rizo1 (Rhizobium sp. aislado) fue superior al nitrato de potasio (N+) luego de 20 días de evaluación. En nivel invernadero, hu...

Maca (Lipidium meyenii Walp,) is a Peruvian product with different properties and health benefits, however, depending on its nature both in its processed state and as a raw material, it can present polluting substances from its natural appearance or state of conservation. The objective of the study was to detect mycotoxigenic molds and identify heavy metals of lead and mercury in maca flour from the Buenos Aires agricultural market in the Carhuamayo District, Huancayo Province and Junín Department. The detection of molds was made by the direct method, appreciating species of the genus Cephalosporium sp. (HMD1) and Penicillium sp. (HMD2) and by the indirect method a dilution (-7) 5x108 cfu / mL of yeast was obtained. In the identification of heavy metals by atomic absorption spectrophotometry, the presence of lead was evidenced in 0.17 mg / kg average amount at the toxic value of the per...

The presence of ochratoxin A (OTA), a mycotoxin with carcinogenic properties, was analyzed in the beans of Theobroma cacao L. "trinitario cacao" from the collection center of Pisana-Tingo Maria, of the San Martin Region, Peru. The samples were collected in four stages of production: harvesting, fermentation, drying and storage. The OTA was extracted using 60 % acetonitrile and purified by immunoaffinity columns and subsequent quantification by high performance liquid chromatography (HPLC). The recovery percentage of the method used was evaluated by using samples fortified with OTA, showing a recovery percentage greater than 95 %. The beans evaluated in the different stages of production did not show the presence of ochratoxin A and in the mycotoxigenic analysis the presence of fungi of the genus Fusarium, Penicillium and yeasts was evidenced.

The aim of the study was to evaluate the antioxidant and antiphotoaging effects of extracts of brown alga Macrocystis integrifolia Bory and develop a dermocosmetic form. From this extracts, was designed the dermocosmetic form in concentrations of 1, 3 and 5%, on a base made of lard with incorporation of beeswax and sesame oil to a pH of 6,5. The antioxidant activity was determined by in vitro methods as CDP and ABTS. The evaluation of antiphotoaging effect in vivo was performed using 25 albino female mice of Mus musculus specie, strain Bald / C53, who were divided into five groups of five mice each; except the group that served as blank, control and intervention groups were depilated hair back and subjected to UVB irradiation for 7 days, morning and night. The in vitro antioxidant activity assay showed that between extracts from stem, foliage and bulb of this alga, there are differences ...

El objetivo del estudio fue evaluar el efecto antioxidante y antifotoenvejecimiento de extractos de la alga parda Macrocystis integrifolia Bory y elaborar una forma dermocosmética. Obtenidos los extractos, se diseñó una forma dermocosmética en concentraciones de 1, 3 y 5%, elaboradas sobre una base de manteca de cerdo con incorporación de cera de abejas y aceite de sésamo a un pH de 6,5. La actividad antioxidante in vitro se determinó por lo métodos CDP y ABTS. La evaluación del efecto antifotoenvejecimiento in vivo se realizó empleando 25 ratones albinos hembra de la especie Mus musculus, cepa Bald/C53, que fueron distribuidos en cinco grupos de cinco ratones cada uno; a excepción del grupo que sirvió de blanco, el grupo control y los grupos de intervención fueron depilados en el lomo y se sometieron a la irradiación UVB durante 7 días, mañana y noche. El ensayo in vitro...