Revista Internacional de Contaminación Ambiental
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Production of vegetables with biofertilizers based on native microorganisms: A case study in Tixtla, Guerrero, Mexico
Get PDFIn agriculture, the use of fertilizers has increased due to the high demand for food by humanity, causing negative impacts because of high production costs and soil contamination. We evaluated five biofertilizers based on native microorganisms promoters of plant growth (NMPPG) as an alternative to the fertilizers used by small vegetable producers. The evaluation was carried out with three types of vegetables (lettuce, celery and epazote) in the Juan Berbera Catalán Irrigation Unit made up by producers from the community of Tixtla, Guerrero. The results show that Rhizobium sp. R01 (Tx3), Azotobacter sp. C3 (Tx1) and Bacillus licheniformis M2-7 (Tx5) used as biofertilizers promote germination and considerably increase fresh weight in these crops, and Azospirillum sp. M9 (Tx2) and Trichoderma sp. ABC1 (Tx4) present significant differences with the negative and chemical control. The yield of lettuce, celery and epazote was favored using biofertilizers, which can be considered a good alternative to apply to these crops, likewise, the price of biofertilizers (5 liters per Tx) compared to the fertilizer DAP-18-46-00 (50 kg) used by the same producers is 2,000.00 MXN per hectare produced respectively. In conclusion, the biofertilizers used herein represent a feasible alternative for farmers without disregarding the need for technical specialists and producers to identify optimal conditions that support the sustained application and management of biofertilizers.In agriculture, the use of fertilizers has increased due to the high demand for food by humanity, causing negative impacts because of high production costs and soil contamination. We evaluated five biofertilizers based on native microorganisms promoters of plant growth (NMPPG) as an alternative to the fertilizers used by small vegetable producers. The evaluation was carried out with three types of vegetables (lettuce, celery and epazote) in the Juan Berbera Catalán Irrigation Unit made up by producers from the community of Tixtla, Guerrero. The results show that Rhizobium sp. R01 (Tx3), Azotobacter sp. C3 (Tx1) and Bacillus licheniformis M2-7 (Tx5) used as biofertilizers promote germination and considerably increase fresh weight in these crops, and Azospirillum sp. M9 (Tx2) and Trichoderma sp. ABC1 (Tx4) present significant differences with the negative and chemical control. The yield of lettuce, celery and epazote was favored using biofertilizers, which can be considered a good alternative to apply to these crops, likewise, the price of biofertilizers (5 liters per Tx) compared to the fertilizer DAP-18-46-00 (50 kg) used by the same producers is 2,000.00 MXN per hectare produced respectively. In conclusion, the biofertilizers used herein represent a feasible alternative for farmers without disregarding the need for technical specialists and producers to identify optimal conditions that support the sustained application and management of biofertilizers
Evaluation method of the coordination degree between landscape protection and tourism development in the traditional village
Get PDFLandscape protection and tourism development are a pair of contradictions in the revitalization of traditional villages. It is an important topic to study the coordination between them. This research reveals the interactive mechanism between the protection of traditional rural features and the development of tourism, based on which the evaluation model and index system of the coordination degree of the composite system are constructed. The result is illustrated by the example of the first three plots of traditional Chinese villages in the Gansu Longzhong area from 2013 to 2018. The evolution trend of the traditional village landscape protection subsystem, the development of the tourism subsystem, and the composite system’s coordination degree were analyzed. The results show that the coordination of traditional village landscape protection and tourism development composite system at the same base period gradually increases. Nevertheless, the coordination between adjacent base periods is at a low level. The increase in the synergy between the landscape protection subsystem and the tourism development subsystem tends to be the same, and the two subsystems are in a positive development that promotes each other. Based on the above conclusions, this research puts forward the coordination strategies and suggestions for the protection of traditional villages and tourism development
Coastline stability analysis of Zhoushan-Liuheng lng terminal project based on remote sensing
Get PDFSeabed evolution research around Zhoushan Liuheng LNG receiving station project, which mainly includes collecting, analyzing and sorting data of environmental investigation, was conducted by the second Institute of Oceanography, MMR. Based on the data of remote sensing and field survey for different years, the comprehensive research methods of dynamic geomorphology, sedimentology, stratigraphy and mathematical simulation are used to carry out the geomorphological investigation of the sea area near the Zhoushan Liuheng LNG terminal project. This paper makes a detailed analysis of the beach dynamics, seabed scouring and silting change characteristics of the project sea area, and makes a prediction of the beach channel scouring and silting adjustment trend caused by sea related projects, which provides a scientific basis for optimizing the plane layout of Zhoushan Liuheng LNG receiving station project and insight for other researchers who focus on coastline change and remote sensing
Resistencia a tetraciclinas en Escherichia coli aislada de aguas superficiales y residuales de Tamaulipas, México
Get PDFAntibiotic resistance represents a threat to global health that increases morbidity and mortality in the population. The excessive and indiscriminate use of antibiotics has led to the emergence and spread of resistant bacteria. Tetracyclines have been one of the most widely used antibiotics because of their broad spectrum and low cost; they are frequently found in aquatic environments because of their low mobility and persistence in such sources. Therefore, the aim of this work was to evaluate tetracycline resistance in Escherichia coli strains isolated from surface water and wastewater in northeastern Tamaulipas, Mexico. In this study, 50 strains of E. coli were analyzed. Susceptibility testing showed that 54% of E. coli strains were resistant to tetracycline, of which 16 and 26% were resistant to minocycline and doxycycline, respectively. Resistance to streptomycin, ampicillin, and sulfamethoxazole-trimethoprim was also identified. Regarding the tet genes, tet(A) was the most prevalent at 74 %, while intI was found at 22 % (p > 0.05). In the conjugation assay, 41 % (11/25) of E. coli strains showed potential to transfer resistance to tetracycline, and only tet(A) was transferred to the recipients in 81 %, while intI was transferred in 27 %. Finally, E. coli strains isolated on the surface and wastewater of northeastern Tamaulipas represent a health and environmental risk because of the potential to spread their resistance in the aquatic environment and other environments and bacterial communities.La resistencia a los antibióticos representa una amenaza para la salud mundial que incrementa la morbilidad y mortalidad de la población. El uso excesivo e indiscriminado de antibióticos ha conducido a la aparición y propagación de bacterias resistentes. Las tetraciclinas han sido uno de los antibióticos más utilizados por su amplio espectro y bajo costo, y son frecuentemente detectados en ambientes acuáticos por su baja movilidad y persistencia. El objetivo de este trabajo fue evaluar la resistencia a tetraciclinas en aislados de Escherichia coli de aguas superficiales y aguas residuales en el noreste de Tamaulipas, México. Se analizaron 50 aislados de E. coli, de los cuales el 54 % fue resistente a tetraciclina; de este porcentaje, 16 y 26 % fueron resistentes a doxiciclina y minociclina, respectivamente. También se identificó resistencia a estreptomicina, ampicilina y trimetoprim-sulfametoxazol. De los genes tet, el más prevalente fue tet(A) en 74 %, mientras que intI se detectó en 22 % (p > 0.05). En el ensayo de conjugación plasmídica, 41 % de los aislados de E. coli transfirieron la resistencia a tetraciclina. Sólo tet(A) se transfirió a las receptoras en 81 %, en tanto que intI en 27 %. Cinco replicones plasmídicos fueron identificados en las transconjugantes. Los aislados de E. coli obtenidos de aguas superficiales y residuales del noreste de Tamaulipas representan un riesgo sanitario y ambiental, ya que tienen el potencial de trasferir los genes de resistencia, no sólo en el medio acuático sino también a otros ambientes y comunidades bacterianas
Modeling analysis of the toxic effects of interior decoration materials waste containing arsenic on wheat
Get PDFThis paper analyzes the toxic effects of arsenic from interior decoration materials waste on wheat seeds and establishes a Terrestrial Biotic Ligand Model (TBLM) toxicity prediction model. The arsenic content of interior decoration materials was diluted to 0.10, 1.00, 5.10, 7.50, 10.00, 15.00, and 25.00 mg/L. The arsenic content was set to 50.00 mg/L to conduct the test. Wheat seeds were added to the above solutions, and the germination rate, root length, shoot length, and α-amylase activity were determined. According to the above eight concentrations of arsenic solution, wheat seedlings were divided into eight groups, and 0.00 mg/L concentration solution was used as the control group. After 30 days of cultivation, stem growth and photosynthesis’s effect on wheat’s root system were measured. The TBLM toxicity prediction model was used to predict the toxicity in the wheat roots. The results showed that 7.50 mg/L arsenic concentration caused the lowest damage to germination rate and germination length, and α-amylase activity in wheat germination was the best. Net photosynthetic rate, transpiration rate, and stomatal conductance all showed a downward trend. When As3+ concentration exceeded 7.50 mg/L, chlorophyll a, b, and carotenoids decreased. The arsenic content in wheat roots increased with the increase in arsenic concentration, and the content of chemical elements also increased. TBLM model considered the influence of ionic strength and competition effect simultaneously, which could more accurately describe the influence of chemical conditions in solution on the toxicity effect on wheat. The above experimental results indicate that arsenic-containing interior decorative materials have a significant toxic impact on wheat. When the arsenic concentration in indoor decoration material waste exceeds 7.50 mg/L, the impact on wheat growth gradually increases.This paper analyzes the toxic effects of arsenic from interior decoration materials waste on wheat seeds and establishes a Terrestrial Biotic Ligand Model (TBLM) toxicity prediction model. The arsenic content of interior decoration materials was diluted to 0.10, 1.00, 5.10, 7.50, 10.00, 15.00, and 25.00 mg/L. The arsenic content was set to 50.00 mg/L to conduct the test. Wheat seeds were added to the above solutions, and the germination rate, root length, shoot length, and α-amylase activity were determined. According to the above eight concentrations of arsenic solution, wheat seedlings were divided into eight groups, and 0.00 mg/L concentration solution was used as the control group. After 30 days of cultivation, stem growth and photosynthesis’s effect on wheat’s root system were measured. The TBLM toxicity prediction model was used to predict the toxicity in the wheat roots. The results showed that 7.50 mg/L arsenic concentration caused the lowest damage to germination rate and germination length, and α-amylase activity in wheat germination was the best. Net photosynthetic rate, transpiration rate, and stomatal conductance all showed a downward trend. When As3+ concentration exceeded 7.50 mg/L, chlorophyll a, b, and carotenoids decreased. The arsenic content in wheat roots increased with the increase in arsenic concentration, and the content of chemical elements also increased. TBLM model considered the influence of ionic strength and competition effect simultaneously, which could more accurately describe the influence of chemical conditions in solution on the toxicity effect on wheat. The above experimental results indicate that arsenic-containing interior decorative materials have a significant toxic impact on wheat. When the arsenic concentration in indoor decoration material waste exceeds 7.50 mg/L, the impact on wheat growth gradually increases
Estudio comparativo de las propiedades mecánicas de concretos modificados con residuos plásticos granulados y no granulados
Get PDFPolyethylene terephthalate (PET) waste and its low recycling rate contribute to the detriment of the environment, it is therefore necessary to use PET waste in different ways, for example as precursor materials in concrete preparation. This work presents the preparation of concrete with pelletized and non pelletized PET waste as replacement by volume of 1.7%, 3.4% and 5% of fine aggregates. An increase of pelletized and non-pelletized PET waste was directly and inversely to slump, respectively. The density decreased with the increase in replacement content in pelletized and not pelletized PET waste. The concrete prepared with pelletized PET exhibited the highest compressive strength, being the concrete mix containing 1.7% of pelletized material, the one that exhibited the highest compressive strength (96% of the traditional material). Furthermore, the mixtures containing 1.7% of non-pelletized material achieved a lower compressive strength (76%). Based on the results, the prepared concrete containing pelletized PET waste presents a solution to plastic waste disposal.Los residuos de tereftalato de polietileno (PET) y su baja tasa de reciclaje contribuyen al detrimento del ambiente, por lo que es necesario utilizarlos de diferentes maneras, por ejemplo, como materiales precursores en la preparación de hormigón. Este trabajo reporta las propiedades mecánicas de concretos preparados con reemplazos del 1.7 %, 3.4 % y 5 % de los finos por residuos plásticos no granulados (plásticos triturados) y granulados. Un aumento de los residuos de PET granulados y no granulados fue directamente e inversamente al asentamiento, respectivamente. La densidad disminuyó con el aumento del contenido de reemplazo en los residuos de PET granulados y no granulados. El concreto elaborado con PET granulado presentó la mayor resistencia a la compresión, siendo la mezcla con 1.7 % de material granulado, la que presentó mayor resistencia a la compresión (96 % del material tradicional). Además, las mezclas que contenían 1.7 % de material no granulado tuvieron una menor resistencia a la compresión (76 %). Con base en los resultados, el concreto preparado que contiene residuos de PET granulados presenta una solución para la eliminación de residuos plásticos
Ionoma radical de Sedum praealtum por microanálisis SEM-EDX en presencia de arsénico y cadmio y la adición de agentes quelantes
Get PDFIonomics considers the qualitative and quantitative evaluation of elemental composition and its changes in the organism physiology. The scanning electron microscopy with energy-dispersive x-ray spectroscopy evaluation (SEM-EDX) technique is and adequate analysis for it because informs about elements localization and chemical composition in biological samples. The present work analyzed the Sedum praealtum radical ionome by the effect of arsenic and cadmium presence and chelating agent addition. Qualitative elemental distribution of P, K, Ca, Cu, Fe, Mn, Mg, Ni, Zn, Mo, As and Cd was evaluated by SEM-EDX microanalysis in root fragments organized in four regions that involved the root tip to the early differentiation zone. The most important pattern obtained was the synergy between As, Cd and ethylenediamine tetraacetic acid chelating agent (EDTA). The highest elemental percentage was obtained under the synergy between As, Cd and ethylenediaminetetraacetic acid chelating agent (EDTA), as an elemental immobilization pattern in the radical surface of this plant species, giving evidence of the sites to absorption and transport of nutrients in the root zones.La ionómica considera la evaluación cualitativa y cuantitativa de la composición elemental y sus cambios en la fisiología de los organismos. La aplicación de la técnica de microscopía electrónica de barrido con la evaluación espectroscópica de la energía de dispersión por rayos X (SEM-EDX: Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy) es un análisis adecuado de ella, ya que informa sobre la localización y composición química elemental en muestras biológicas. En este trabajo se analizó el ionoma radical de Sedum praealtum bajo la presencia de arsénico y cadmio con la adición de agentes quelantes. Se evaluó la distribución elemental semicuantitativa de P, K, Ca, Cu, Fe, Mn, Mg, Ni, Zn, Mo, As y Cd por microanálisis SEM-EDX en fragmentos de raíz agrupados en cuatro regiones desde el ápice hasta el inicio de la zona de diferenciación. Se obtuvo como patrón de distribución importante el de la sinergia entre el As y el Cd y el agente quelante, el ácido etilenodiaminatetraacético (EDTA). Se obtuvo el mayor porcentaje elemental bajo la sinergia entre el As y el Cd y el agente quelante, el ácido etilendiaminotetraacético (EDTA) como patrón de la inmovilización elemental en la superficie radical de esta especie, que dio evidencia de los sitios de absorción y transporte de nutrientes en las zonas radicales
Comparative study of bioconcentration potential and biomarkers in Biomphalaria glabrata exposed to ZnO nanoparticles and bulk ZnO
Get PDFThe uptake of nanoparticles (NPs) by aquatic invertebrates can lead to adverse health effects. The aims of the present study were: 1) to investigate the bioconcentration potential of ZnO NPs or its bulk analogous in Biomphalaria glabrata gastropods by measuring the soft tissue Zn content, and 2) to determine the responses elicited by the exposed snails through the analysis of recognized biomarkers of effect at the subcellular level. Snails exposed to 5 mg/L ZnO NPs or bulk ZnO for 48 h showed a significant higher soft tissue Zn content than control animals, with no significant differences between NPs- and bulk-treated snails. No significant differences were observed in the levels of lipid peroxidation and in the activities of acetylcholinesterase, carboxylesterase and catalase by 48 h-exposure to ZnO NPs or bulk ZnO with respect to control organisms. However, ZnO exposure induced a significant decrease in glutathione tissue content, without a nano-specific effect. The results as a whole encourage further studies to better understand the impact that engineered NPs may have on freshwater invertebrate species.The uptake of nanoparticles (NPs) by aquatic invertebrates can lead to adverse health effects. The aims of the present study were: 1) to investigate the bioconcentration potential of ZnO NPs or its bulk analogous in Biomphalaria glabrata gastropods by measuring the soft tissue Zn content, and 2) to determine the responses elicited by the exposed snails through the analysis of recognized biomarkers of effect at the subcellular level. Snails exposed to 5 mg/L ZnO NPs or bulk ZnO for 48 h showed a significant higher soft tissue Zn content than control animals, with no significant differences between NPs- and bulk-treated snails. No significant differences were observed in the levels of lipid peroxidation and in the activities of acetylcholinesterase, carboxylesterase and catalase by 48 h-exposure to ZnO NPs or bulk ZnO with respect to control organisms. However, ZnO exposure induced a significant decrease in glutathione tissue content, without a nano-specific effect. The results as a whole encourage further studies to better understand the impact that engineered NPs may have on freshwater invertebrate species
Aislamiento de Brucella melitensis en suelo agrícola, Puebla, México
Get PDFBrucellosis is an important zoonotic disease due to its global distribution, infectious-contagious potential (half a million new patients yearly), and a wide variety of niches (livestock, humans, wildlife, water, and air). A large part of these effects on the productive yields of cattle and goats in the Emilio Portes Gil community in the municipality of Puebla, Mexico, is attributed to Brucella. Therefore, this study aims to isolate Brucella sp. in agricultural soil samples in an area with a high incidence in animals and humans. Agricultural soil samples were used (n = 90). By standard microbiological methods, Brucella melitensis was isolated, and its presence was detected and confirmed in the analyzed samples, 100% for the primary isolation (total samples), 69.8% during reseeding, and 57% in the endpoint PCR confirmatory tests (using BM16 and E. coli as controls). The bp26 gene was amplified by 1024 bp, and the microbiological profiles were identical for B. melitensis. This is the first record of detection, isolation, and confirmation of B. melitensis in agricultural soil in Mexico. The soil system is recognized as an extension of the niche for B. melitensis. These data constitute a useful tool to improve understanding of the pathogenesis and virulence of the Brucella genus in a natural environment and its potential effect on public and animal health.La brucelosis es una enfermedad zoonótica importante debido a su distribución mundial, su potencial infectocontagioso (medio millón de nuevos pacientes cada año) y su gran variedad de nichos (ganado, humanos, fauna silvestre, agua, aire). Se atribuye a Brucella gran parte de la alta afectación en los rendimientos productivos de ganado vacuno y caprino en la comunidad Emilio Portes Gil del municipio de Puebla, México. Por ello, el objetivo de este estudio fue aislar a Brucella sp. en muestras de suelo agrícola (n = 90) en una zona de alta incidencia en humanos y ganado. Por medio de métodos microbiológicos estándares se aisló, detectó y confirmó la presencia de Brucella melitensis en las muestras analizadas, con una efectividad del 100 % durante el primoaislamiento (total de muestras), 69.8 % para la resiembra y 57 % en las pruebas confirmatorias PCR de punto final (PCR-PF) utilizando BM16 y E. coli como testigos. Se amplificó el gen bp26 con 1024 pb y los perfiles microbiológicos resultaron comparativamente idénticos para B. melitensis. Este es el primer registro de detección, aislamiento y confirmación de B. melitensis en suelo agrícola en México. Se reconoce al sistema suelo como una extensión del nicho para B. melitensis. Estos datos constituyen una herramienta útil para mejorar la comprensión sobre la patogénesis y virulencia del género Brucella en el medio natural, así como su efecto potencial en la salud pública y animal
Evaluación ecotoxicológica de las interacciones entre paracetamol e ibuprofeno sobre la microalga de agua dulce Pseudokirchneriella subcapitata
Get PDFEmerging contaminants, such as drugs for human and veterinary use, are of growing concern due to their potential toxic effects on aquatic organisms. The anti-inflammatories paracetamol and ibuprofen are among the most consumed drugs worldwide and have been found in aquatic ecosystems such as rivers and lakes. The aim of this work was to evaluate the toxicity of paracetamol and ibuprofen and their interactions on the microalga Pseudokirchneriella subcapitata. For this purpose, increasing concentrations of both pharmaceutical compounds were prepared, toxicity bioassays were performed with P. subcapitata, while for interactions, binary mixtures were prepared in the following ratios: 4:1, 1:4, and 1:1 according to the CI20 previously determined. The interactions were determined according to the concentration-addition and synergy-ratio models. The results show that the toxicity of ibuprofen was higher than paracetamol (72-h CI20 of 12.7 and 23.9 mg/L, respectively). The interactions were classified as antagonistic. In conclusion, the results suggest a low environmental risk for primary producers such as the microalgae P. supcapitata, since the concentrations that cause toxic effects are higher than those reported in natural aquatic ecosystems such as lakes and rivers in different parts of the world. On the other hand, the joint presence of both drugs inhibits their individual toxicities on P. subcapitata.Los contaminantes emergentes, tales como fármacos de uso humano y veterinarios, generan creciente preocupación por sus efectos tóxicos potenciales en organismos acuáticos. Los antinflamatorios paracetamol e ibuprofeno están entre los fármacos más consumidos a nivel mundial y se han encontrado en ecosistemas acuáticos como ríos y lagos. El objetivo de este trabajo fue evaluar la toxicidad de paracetamol e ibuprofeno y sus interacciones sobre la microalga Pseudokirchneriella subcapitata. Para ello, se prepararon concentraciones crecientes de ambos compuestos farmacéuticos y se realizaron bioensayos de toxicidad con P. subcapitata, en tanto que para las interacciones se prepararon mezclas binarias en proporciones de 4:1, 1:4 y 1:1 de acuerdo con los CI20 determinados previamente. Las interacciones se determinaron de acuerdo con los modelos concentración-adición y proporción-sinergia. Los resultados muestran que la toxicidad del ibuprofeno fue mayor que la de paracetamol (CI20-72 h de 12.7 y 23.9 mg/L, respectivamente). Las interacciones se clasificaron como antagónicas. En conclusión, los resultados sugieren un bajo riesgo ambiental para los productores primarios como la microalga P. supcapitata, ya que las concentraciones que provocan efectos tóxicos son superiores a las reportadas en ecosistemas acuáticos naturales como lagos y ríos en diferentes partes del mundo. Por otra parte, la presencia conjunta de ambos fármacos inhibe sus toxicidades individuales sobre P. subcapitata