Extra virgin olive oil: does it modify milk composition of hair sheep?

The aim of this study was to determine the effect of olive oil addition on the production, chemical composition, and fatty acid profile of sheep’s milk. Twenty-four lactating ewes with a live weight of 34.6 ± 4.61 kg were used. The animals were randomly distributed into four treatments (n = 6) with dietary addition of 0%, 2%, 4%, and 6% (dry matter basis) olive oil for 45 days. Milk samples were taken every 7 days for fatty acid (FA) and chemical analyses. A decrease (p < 0.05) in dry matter and crude protein intake was observed with 4% oil inclusion. Milk production and milk components were similar between treatments. The kilograms of meat from weaned lambs linearly increased as the oil inclusion increased. Milk C4:0 to C17:0 decreased with 2% olive oil. The monounsaturated and polyunsaturated FA content in the milk increased with the oil inclusion. There was an increase in the milk’s linoleic acid, linolenic acid, and eicosapentaenoic acid content with 2% olive oil. Overall, the addition of 2% extra virgin olive oil is recommended to improve milk’s FA profile without negative effects on animal performance

Caracterización de bacterias ácido lácticas con actividad antimicrobiana aisladas del queso crema de Chiapas, México

Chiapas cream cheese is an artisanal product manufactured in different regions of Mexico. The ability of lactic bacteria to produce large amounts of lactic and acetic acid has the effect of decreasing the pH, considered one of the primary factors in the inhibition of undesirable microorganisms such as pathogens and coliform bacteria, in dairy foods. The objective of this work was to isolate lactic acid bacteria and evaluate their antagonistic effect against pathogenic bacteria in vitro, as well as their effect against pathogens that are present in milk when they are added in the preparation of cream cheese. Strains of lactic bacteria were isolated from cream cheese from Chiapas, Mexico. Isolates were identified by API 50CH biochemical tests and 16S ribosomal gene sequences. The bacteria under study were used in pathogen growth inhibition tests. The production of acetic and lactic acid was quantified by gas chromatography coupled to masses in the cheeses at the beginning and 10 d after its elaboration. 203 bacterial strains were isolated, 82 of which had the ability to inhibit the growth of 7 pathogenic bacterial strains. The strains were identified by the partial sequence of the 16S ribosomal gene as belonging to the genus Lactobacillus; The addition of these strains in the elaboration of cream cheese reduces or eliminates coliforms, Staphylococcus aureus, molds and yeasts, while in the cheese made with pasteurized milk 290 CFU/mL of molds and yeasts were detected. These results suggest that Lactobacillus strains isolated from Chiapas artisanal cream cheese has the potential to be used as a starter culture with bioconservation activity in this and similar products.El queso crema de Chiapas es un producto artesanal fabricado en diferentes regiones de México. La capacidad de las bacterias lácticas, de producir grandes cantidades de ácido láctico y acético, tiene como efecto la disminución del pH, considerado uno de los factores primarios en la inhibición de microorganismos indeseables, como patógenos y bacterias coliformes, en alimentos lácteos. El objetivo de este trabajo fue aislar bacterias ácido lácticas y evaluar su efecto antagónico contra bacterias patógenas in vitro y contra patógenos presentes en la leche cuando se adicionan durante la elaboración del queso crema. Se aislaron cepas de bacterias lácticas del queso crema de Chiapas, México. Los aislados fueron identificados mediante pruebas bioquímicas API 50CH y secuencias del gen ribosomal 16S. Las bacterias de interés se usaron en pruebas de inhibición del crecimiento con cepas patógenas. Se cuantificó la producción de ácido acético y láctico por cromatografía de gases acoplado a masas en los quesos, al inicio y a los 10 d posteriores a su elaboración. Se aislaron 203 cepas bacterianas, de las cuales 82 tuvieron la capacidad de inhibir el crecimiento de 7 cepas bacterianas patógenas. Las cepas fueron identificadas por la secuencia parcial del gen ribosomal 16S como pertenecientes al género Lactobacillus; la adición de estas cepas en la elaboración del queso crema redujo o eliminó coliformes, Staphylococcus aureus, mohos y levaduras, mientras que en el queso elaborado con leche pasteurizada se detectaron 290 UFC/mL de mohos y levaduras. Estos resultados sugieren que las cepas de Lactobacillus aisladas del queso crema artesanal de Chiapas tienen potencial para su uso como cultivo iniciador con actividad de bioconservación en este y productos similares

Experimental Methodology for the Separation Materials in the Recycling Process of Silicon Photovoltaic Panels

As the use of photovoltaic installations becomes extensive, it is necessary to look for recycling processes that mitigate the environmental impact of damaged or end-of-life photovoltaic panels. There is no single path for recycling silicon panels, some works focus on recovering the reusable silicon wafers, others recover the silicon and metals contained in the panel. In the last few years, silicon solar cells are thinner, and it becomes more difficult to separate them from the glass, so the trend is towards the recovery of silicon. In this paper, we investigate the experimental conditions to delaminate and recovery silicon in the recycling process, using a combination of mechanical, thermal, and chemical methods. The conditions of thermal treatment to remove the ethylene-vinyl acetate (EVA) layer were optimized to 30 min at 650 °C in the furnace. To separate silicon and metals, the composition of HF/HNO3 solution and the immersion time were adjusted considering environmental aspects and cost. Under the selected conditions, panels from different manufacturers were tested, obtaining similar yields of recovered silicon but differences in the metal concentrations

Bacteria from Jatropha curcas rhizosphere, degrades aromatic hydrocarbons and promotes growth in Zea mays

The rhizosphere is one of the most important reservoirs of microorganisms. Because of the microbial metabolic activities, these can be used for various biotechnological, agricultural and environmental purposes. In this study we evaluated five genetically related bacterial strains; Pseudomonas aeruginosa N7B1 (MG457074), Pseudomonas sp. (MG457075), Pseudomonas sp., Bf1 (MG457076) and Pseudomonas aeruginosa F23 (MG457077), isolated from Jatropha curcas rhizosphere, capable of growing and degradating benzene and phenanthrene. The hydrocarbon degradation by these strains was quantified by gas chromatography coupled to mass spectrophotometry. The Pseudomonas aeruginosa N7B1 strain removed 84% of phenanthrene and 45% of benzene in a seven-day period, while the other strains showed a lower hydrocarbon degradation capacity. Another biotechno-logical feature of these strains is maize growth promotion, in a substrate enriched with 0.5% of phenanthrene and 1.0% of benzene. Pseudomonas aeruginosa N7B1 and Pseudomonas aeruginosa F23 showed an increase in root and shoot fresh and dry weight, plant height and root length variables. These results open the possible use of these strains as bioinoculants to promote the growth of maize plants in phenanthrene and benzene polluted soils

Degradación de Fenantreno por bacterias del género Burkholderia y Rhizobium aisladas de nódulos de mimosas

Abstract The present work aimed to identify and evaluate degradation capacity of microorganisms isolated from mimosa nodules, which can be used in bioremediation processes of soils contaminated with phenanthrene. Method: Isolation of 122 bacterial strains of mimosa nodules was grown in the Maconkey culture medium to discard enterobacteria; the bacterial strains that resulted negative to this test, were inoculated in the culture medium containing only phenanthrene source carbon. Three isolates had the capacity to grow in this medium. The three strains were identified by sequence of the 16s ribosomal gene, their capacity to grow in the presence of phenanthrene was assessed by microbial growth curves; the ability to degrade phenanthrene of the three strains was quantified by mass-coupled gas chromatography. Results: The sequences obtained from the 16s ribosomal gene are genetically related to the strains of Burkholderia phenoliruptrix, Burkholderia phymatum and Rhizobium paknamense. The microbial growth of the three strains, supplied with phenanthrene, had a similar behavior to the control, which contained succinate as a carbon source. The strain of Burkholderia sp. BB26 degraded 78.5%, Burkholderia sp. BB24 68.5% and Rhizobium sp. BY8 99%. Discussion: The results of phenanthrene degradation by Burkholderia sp. BB26, Burkholderia sp. BB24 and Rhizobium sp. BY8 strains suggest that the three strains have potential to be used in bioremediation processes of soils contaminated with phenanthrene.Resumen El presente trabajo tuvo como objetivo identificar y evaluar la capacidad de degradación de microorganismos aislados de nódulos de mimosas, que puedan ser utilizados en procesos de biorremediación de suelos contaminados con fenantreno. Método: Se realizó el aislamiento de 122 cepas bacterianas de nódulos de mimosas; fueron crecidas en el medio de cultivo Maconkey para descartar enterobacterias. Las cepas bacterianas que dieron resultado negativo a esta prueba, fueron inoculadas en el medio de cultivo que contenía como única fuente de carbono fenantreno; tres aislados tuvieron la capacidad de crecer en este medio. Las tres cepas fueron identificadas por secuencia del gen 16s ribosomal, se evaluó su capacidad de crecimiento en presencia de fenantreno mediante curvas de crecimiento microbiano; la capacidad para degradar fenantreno de las tres cepas fue cuantificada por cromatografía de gases acoplado a masas. Resultados: Las secuencias obtenidas del gen 16s ribosomal tienen relación genética con las especies de Burkholderia phenoliruptrix, Burkholderia phymatum y Rhizobium paknamense. El crecimiento microbiano de las tres cepas, suministradas con fenantreno, tuvieron un comportamiento similar al control, el cual contenía succinato como fuente de carbono. La cepa de Burkholderia sp. BB26 degradó 78.5 %, Burkholderia sp. BB24 68.5% y Rhizobium sp. BY8 99%. Discusión: Los resultados de degradación de fenantreno por las cepas de Burkholderia sp. BB26, Burkholderia sp. BB24 y Rhizobium sp. BY8 sugieren que las tres cepas tienen potencial para utilizarse en procesos de biorremediación de suelos contaminados con fenantreno

Toxicological Screening of Four Bioactive Citroflavonoids: In Vitro, In Vivo, and In Silico Approaches

Many studies describe different pharmacological effects of flavonoids on experimental animals and humans. Nevertheless, few ones are confirming the safety of these compounds for therapeutic purposes. This study aimed to investigate the preclinical safety of naringenin, naringin, hesperidin, and quercetin by in vivo, in vitro, and in silico approaches. For this, an MTT-based cytotoxicity assay in VERO and MDCK cell lines was performed. In addition, acute toxicity was evaluated on Wistar rats by OECD Guidelines for the Testing of Chemicals (Test No. 423: Acute Oral Toxicity-Class Method). Furthermore, we used the ACD/Tox Suite to predict toxicological parameters such as hERG channel blockade, CYP450 inhibition, and acute toxicity in animals. The results showed that quercetin was slightly more cytotoxic on cell lines (IC50 of 219.44 ± 7.22 mM and 465.41 ± 7.44 mM, respectively) than the other citroflavonoids. All flavonoids exhibited an LD50 value > 2000 mg/kg, which classifies them as low-risk substances as OECD guidelines established. Similarly, predicted LD50 was LD50 > 300 to 2000 mg/kg for all flavonoids as acute toxicity assay estimated. Data suggests that all these flavonoids did not show significant toxicological effects, and they were classified as low-risk, useful substances for drug development