Mycoremediation of Atrazine in a Contaminated Clay-Loam Soil and its Adsorption-Desorption Kinetic Parameters

Clean-up of contaminated soils with atrazine is an ecological responsibility. The objectives of this study are to evaluate atrazine degradation in a clay-loam soil microcosm using fungal enzyme extracts from Trametes maxima and its co-culture with Paecilomyces carneus and to determine the kinetic parameters of the adsorption-desorption of atrazine in soil. Fungal co-culture extract (T. maxima-P. carneus) and monoculture (T. maxima) were able to degrade 100% of atrazine. However, we observed variation in atrazine degradation over the course of the evaluated time period, which suggests that an adsorption-desorption process is occurring in the soil. Adsorption-desorption kinetic parameters of the Freundlich model revealed that the studied soil has a significant capacity to adsorb atrazine (KF = 8.2148; r2 = 0.992 and P-value < 0.0001), while according to the desorption parameters (KF = 5.4992; r2 = 0.245 and P-value = 0.036) and hysteresis index (H = 0.573), the soil does not desorb atrazine at the same rate. Fungal enzyme extracts from a monoculture and co culture of T. maxima were able to degrade atrazine in a short time period (< 12 h). The ability of the contaminated soils to adsorb and desorb atrazine should be taken into account in mycoremediation systems

In situ biosurfactant production and hydrocarbon removal by Pseudomonas putida CB-100 in bioaugmented and biostimulated oil-contaminated soil

In situ biosurfactant (rhamnolipid) production by Pseudomonas putida CB-100 was achieved during a bioaugmented and biostimulated treatment to remove hydrocarbons from aged contaminated soil from oil well drilling operations. Rhamnolipid production and contaminant removal were determined for several treatments of irradiated and non-irradiated soils: nutrient addition (nitrogen and phosphorus), P. putida addition, and addition of both (P. putida and nutrients). The results were compared against a control treatment that consisted of adding only sterilized water to the soils. In treatment with native microorganisms (non-irradiated soils) supplemented with P. putida, the removal of total petroleum hydrocarbons (TPH) was 40.6%, the rhamnolipid production was 1.54 mg/kg, and a surface tension of 64 mN/m was observed as well as a negative correlation (R = -0.54; p < 0.019) between TPH concentration (mg/kg) and surface tension (mN/m), When both bacteria and nutrients were involved, TPH levels were lowered to 33.7%, and biosurfactant production and surface tension were 2.03 mg/kg and 67.3 mN/m, respectively. In irradiated soil treated with P. putida, TPH removal was 24.5% with rhamnolipid generation of 1.79 mg/kg and 65.6 mN/m of surface tension, and a correlation between bacterial growth and biosurfactant production (R = -0.64; p < 0.009) was observed. When the nutrients and P. putida were added, TPH removal was 61.1%, 1.85 mg/kg of biosurfactants were produced, and the surface tension was 55.6 mN/m. In summary, in irradiated and non-irradiated soils, in situ rhamnolipid production by P. putida enhanced TPH decontamination of the soil

Evaluación preliminar de la remoción de Nitrógeno total y Ortofosfato de aguas residuales por chlorella sp., en un fotobiorreactor airlift

En el presente estudio se evaluó la remoción de nitrógeno total y ortofosfato de aguas residuales provenientes del ramal 1 del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional en México D. F. por Chlorella sp., en un fotobiorreactor airlift, bajo diferentes flujos de aire y concentraciones de inóculo, para lo cual se empleó un diseño factorial 22. En el primer tratamiento se empleó 10% (200 mL) de inóculo de Chlorella sp., y se adicionó un volumen de agua residual (1800 mL) con un flujo de aire de 1.5 L/min, los tres tratamientos restantes se realizaron variando los niveles de flujo de aire (1.5 y 2.5 L/min) y la concentración del inóculo (10%,30%). Los mejores resultados se obtuvieron en el tratamiento cuatro bajo un flujo de aire de 2.5 L/min y una concentración de inóculo de 30%, en el cual se observó una alta reducción de unidades de nitrógeno y ortofosfato de 66 mg/L y 6.4 mg/L respectivamente, así como buen rendimiento de clorofila A con una concentración de 11.71 mg/L.Palabras clave: aguas residuales, biorremediación, microalgas, fotobiorreactor

Effect of the Pesticide Endosulfan and Two Different Biostimulants on the Stress Responses of Phaseolus leptostachyus Plants Grown in a Saline Soil

[EN] Soil salinity and the indiscriminate use of agrochemicals has significantly reduced the productivity of the Chinampas agroecosystem in Mexico City. Crop improvement under these stressful conditions may be achieved by soil bioremediation. In this study, we checked the effects of the organochlorine pesticide endosulfan and bioremediation with Penicillium crustosum or a citric waste on the growth of Phaseolus leptostachyus plants in saline soil from the Chinampas area. Biochemical markers associated with specific stress responses were also determined after one month of growth in the different substrates. Plant growth was stimulated by bioremediation of the soil. Both biostimulants reduced the degree of stress affecting the plants, as shown by the increase in photosynthetic pigments and the reduction of proline, malondialdehyde (MDA), and H2O2 contents, and the activation of antioxidant systems. However, the biostimulants appeared to mitigate oxidative stress through different mechanisms. Endosulfan contamination inhibited seed germination¿which was reverted to control values in the presence of the biostimulants¿and further decreased plant growth. No clear patterns of variation of biochemical stress markers were observed combining endosulfan and the biostimulants. In any case, bioremediation with P. crustosum and/or citric waste is recommended to improve the germination and growth of P. leptostachyus plants.Anbu Landa-Faz is grateful to CONACYT, Mexico, for receiving the Ph.D. Scholarship no 306251 to support her stay at Universitat Politecnica de Valencia.Landa-Faz, A.; González-Orenga, S.; Boscaiu, M.; Rodríguez-Vázquez, R.; Vicente, O. (2021). Effect of the Pesticide Endosulfan and Two Different Biostimulants on the Stress Responses of Phaseolus leptostachyus Plants Grown in a Saline Soil. Agronomy. 11(6):1-18. https://doi.org/10.3390/agronomy11061208S11811

Ordenación de comunidades de fitoplancton en el lago de Chapala, Jalisco-Michoacán, México

We investigated what environmental variables explained major axes of compositional variation in phytoplankton communities at the Chapala lake. We used presence-absence data for the ordination analysis, which included 96 phytoplankton samples and 116 species. The primary gradient of the phytoplankton community structure, obtained from Bray-Curtis variance-regression, was explained by sulfates (r=0.751) and inversely by total alkalinity (r=-0.635). The secondary compositional gradient of phytoplankton communities, which was independent from the primary one, was explained by hardness of water due to Calcium (r=-0.617) and by total hardness (r=-0.602). The remainder of environmental variables (16) showed no relationship to any of the ordination axis. These data suggest habitat preference for most communities of phytoplankton toward higher sulfate concentration and toward low total alkalinity levels. Only few species showed specialization toward low sulfate concentration and toward high total alkalinity. Two groups of community were shown, which are separated from each other on differences on sulfates and total alkalinity levels. In addition these data showed a relationship to the last sampling period. A decrease in sulfur, in the form of sulfate, and an increase of total alkalinity from 1996 to 1998, due in part to a decrease of the lake level, associated to the El Niño effect, explained also a decline in species diversity through this period. In conclusion, alkalinity and sulfates seem to be major environmental factors explaining relevant compositional gradients as well as species richness of the phytoplankton communities at the Chapala Lake.Se investigó cuales variables fisicoquímicas explican mejor los ejes de composición florística de las comunidades de fitoplancton en el lago de Chapala. Con base en datos de presencia-ausencia, se ordenaron 96 muestras de fitoplancton, con 116 especies. El gradiente primario de la composición de comunidades, generado mediante la ordenación de Bray-Curtis regresión de varianza, fue explicado por la concentración de sulfatos (r=0.751) y en relación inversa por la alcalinidad total (r=-0.635). El gradiente secundario de la estructura de comunidades, el cual es independiente del primario, fue explicado por la dureza debida al calcio (r=-0.617) y por la dureza total (r=- 0.602). Las restantes variables medidas (16) no mostraron relación con los principales ejes de la ordenación de las comunidades. Los datos sugieren para la mayoría de las comunidades de fitoplancton una preferencia de hábitat hacia altas concentraciones de sulfatos y baja alcalinidad total, mientras que para ciertas especies una especialización hacia alta alcalinidad y bajas concentraciones de sulfatos. Se reconocen dos grupos de comunidades, los cuales además de estar separados por diferencias en concentración de sulfatos y alcalinidad total muestran una relación con el último periodo de colecta. La disminución del azufre, disponible como sulfatos y el incremento de alcalinidad de 1996-1998, debida a la disminución del nivel del lago, asociados al fenómeno de El Niño (1996-1998), explican también la disminución de la riqueza de especies observada en dicho periodo. En conclusión, los sulfatos y la alcalinidad fueron más importantes para la composición y riqueza de las comunidades de fitoplancton en el lago de Chapala

Activation of Peptidylarginine Deiminase in the Salivary Glands of Balb/c Mice Drives the Citrullination of Ro and La Ribonucleoproteins

The goal of the present study was to determine whether peptidylarginine deiminase PAD2 and PAD4 enzymes are present in Balb/c mouse salivary glands and whether they are able to citrullinate Ro and La ribonucleoproteins. Salivary glands from Balb/c mice were cultured in DMEM and supplemented with one of the following stimulants: ATP, LPS, TNF, IFNγ, or IL-6. A control group without stimulant was also evaluated. PAD2, PAD4, citrullinated peptides, Ro60, and La were detected by immunohistochemistry and double immunofluorescence. PAD2 and PAD4 mRNAs and protein expression were detected by qPCR and Western blot analysis. PAD activity was assessed using an antigen capture enzyme-linked immunosorbent assay. LPS, ATP, and TNF triggered PAD2 and PAD4 expression; in contrast, no expression was detected in the control group (p < 0 001). PAD transcription slightly increased in response to stimulation. Additionally, PAD2/4 activity modified the arginine residues of a reporter protein (fibrinogen) in vitro. PADs citrullinated Ro60 and La ribonucleoproteins in vivo. Molecular stimulants induced apoptosis in ductal cells and the externalization of Ro60 and La ribonucleoproteins onto apoptotic membranes. PAD enzymes citrullinate Ro and La ribonucleoproteins, and this experimental approach may facilitate our understanding of the role of posttranslational modifications in the pathophysiology of Sjögren’s syndrome

Photoactive TiO 2 Films Formation by Drain Coating for Endosulfan Degradation

Heterogeneous photocatalysis is an advanced oxidation process in which a photoactive catalyst, such as TiO 2 , is attached to a support to produce free radical species known as reactive oxygen species (ROS) that can be used to break down toxic organic compounds. In this study, the draining time, annealing temperature, and draining/annealing cycles for TiO 2 films grown by the drain coating method were evaluated using a 2 3 factorial experimental design to determine the photoactivity of the films via endosulfan degradation. The TiO 2 films prepared with a large number of draining/annealing cycles at high temperatures enhanced ( &gt; 0.05) endosulfan degradation and superoxide radical generation after 30 minutes of illumination with UV light. We demonstrated a negative correlation ( 2 = 0.69; &gt; 0.01) between endosulfan degradation and superoxide radical generation. The endosulfan degradation rates were the highest at 30 minutes with the F6 film. In addition, films prepared using conditions F1, F4, and F8 underwent an adsorption/desorption process. The kinetic reaction constants, app (min −1 ), were 0.0101, 0.0080, 0.0055, 0.0048, and 0.0035 for F6, F2, F5, F3, and F1, respectively. The endosulfan metabolites alcohol, ether, and lactone were detected and quantified at varying levels in all photocatalytic assays

Efeito dos nutrientes e as condições de fermentação na produção de biossurfactantes com rizobactérias isoladas da piteira.

Objective. To isolate biosurfactant-producing microorganisms from the rhizosphere of fique and to select the best genus to evaluate the effect of nutritional and fermentation conditions on the production of rhamnolipids. Materials and methods. Rhizospheric soil was sampled in three areas of Cauca. The best genus was selected for the experimental designs (Plackett Burman and 22 factorial) and to find the production conditions for the growth kinetics at an Erlenmeyer flask scale. Results. Isolates from the rhizosphere of fique plants were from groups (or genera) of Bacillus, Pseudomonas and Streptomyces, being Pseudomonas the more responsive in preliminary testing for emulsification. From the results of the experimental designs and the kinetics of production, we found that rhamnose synthesis associated with rhamnolipids (3.2 g/l) and emulsification (68% EC24) was significantly favored (p &lt;0.0001) by cultivating an inoculum of 10% v/v of Pseudomonas fluorescens in a medium composed of: soybean oil 2% (v/v), K2HPO4 0.2% (w/v), yeast extract 0.4 g/l, NH4NO3 3.7 g/l, 1 ml trace elements (CoCl3 20 mg/l, H3BO3 30 mg/l, ZnSO4 10 mg/l, Cu2SO4 1 mg/l, Na2MoO4 3 mg/l, FeSO4 10 mg/l MnSO4 2,6 mg/l) and pH 7.2. Conclusion. Of all the microbial genera isolated from the rhizosphere of fique, Pseudomonas fluorescens had the greatest potential in the production of biosurfactants of the rhamnolipids family. Key words: Pseudomonas fluorescens, biosurfactant, rhamnose, emulsification index, soybean oil.  Objetivo. Aislar microorganismos de la rizosfera de fique capaces de producirbiosurfactantes y seleccionar el mejor género para evaluar el efecto de las condiciones nutricionales y de fermentación en la producción de ramnolípidos. Materiales y métodos. Se realizaron muestreos de suelos rizosféricos en tres zonas del Cauca. El mejor género fue seleccionado para realizar los diseños experimentales (Plackett Burman y factorial 22) y establecer las condiciones de producción para las cinéticas de crecimiento a escala de Erlemeyer. Resultados. Se aislaron bacterias del género Bacillus, Pseudomonas y del grupo Streptomyces, siendo Pseudomonas el grupo con mayor respuesta en las pruebas preliminares de emulsificación. A partir de los resultados obtenidos en los diseños experimentales y cinéticas de producción, se estableció que la síntesis de ramnosa asociada con ramnolípidos (3,2 g/l) y la emulsificación (68% EC24) se favorecieron significativamente (p&lt;0.0001) al cultivar un inoculo de 5% v/v de Pseudomonas fluorescens en un medio compuesto por: aceite de soya 2% (v/v), K2HPO4 0,2 % (p/v), extracto de levadura 0,4 g/l,NH4NO3 3,7 g/l, 1 ml de elementos traza (CoCl3 20 mg/l, H3BO3 30 mg/l, ZnSO4 10 mg/l, Cu2SO4 1 mg/l, Na2MoO4 3 mg/l, FeSO4 10 mg/l MnSO4 2,6 mg/l) y pH 7.2. Conclusión. Se aislaron 3 géneros microbianos a partir de rizosfera de fique, siendo Pseudomonas fluorescens la bacteria con mayor potencial en la producción de biosurfactantes de la familia de los ramnolípidos.Palabras clave: Pseudomonas fluorescens, biosurfactante, ramnosa, índice de emulsificación, aceite de soya.Objetivo. Isolar microorganismos da rizosfera da piteira capazes de produzir biossurfactantes, selecionar o melhor gênero para avaliar o efeito das condições nutricionais e de fermentação na produção de rhamnolipídeos. Materiais e métodos. Foram realizadas amostragem de solos rizosféricos em três áreas do Cauca. O melhor gênero foi selecionado para realizar desenhos experimentais (Plackett Burman e fatorial 22) e definir as condições de produção para as cinéticas em escala de erlenmeyer. Resultados. Foram isoladas bactérias do gênero Bacillus, Pseudomonas e grupo de Streptomyces. As Pseudomonas foram o grupo com maior resposta nos testes preliminares de emulsificação. A partir dos resultados obtidos nos desenhos experimentais e cinéticas de produção foi estabelecido que a síntese de ramnose associados com rhamnolipídeos (3,2 g/l) e a emulsificação (68% EC24) foram favorecidos significativamente (p&lt;0,0001) ao cultivar um inoculo de 5% v/v de Pseudomonas fluorescens em um meio composto por: óleo de soja 2% (v/v), K2HPO4 0,2% (p/v), extrato de levedura 0,4 g/l, NH4NO3 3,7 g/l, 1 ml de oligoelementos (CoCl3 20 mg/l, H3BO3 30 mg/l, ZnSO4 10 mg/l, Cu2SO4 1 mg/l, Na2MoO4 3 mg/l, FeSO4 10 mg/l MnSO4 2,6 mg/l) e pH 7,2. Conclusão. Três gêneros microbianos foram isolados da rizosfera da piteira, sendo Pseudomonas fluorescens a bactéria com maior potencial na produção de biossurfactantes da família dos rhamnolipídeos. Palavras-chave: Pseudomonas fluorescens, biossurfactante, ramnose, o índice de emulsificação e óleo de soja

Enhancement of ligninolytic enzyme activities in a Trametes maxima–Paecilomyces carneus co-culture: Key factors revealed after screening using a Plackett–Burman experimental design

Background: In the industrial biotechnology, ligninolytic enzymes are produced by single fungal strains. Experimental evidence suggests that co-culture of ligninolytic fungi and filamentous microfungi results in an increase laccase activity. In this topic, only the ascomycete Trichoderma spp. has been studied broadly. However, fungal ligninolytic-filamentous microfungi biodiversity interaction in nature is abundant and poorly studied. The enhancement of laccase and manganese peroxidase (MnP) activities of Trametes maxima as a function of time inoculation of Paecilomyces carneus and under several culture conditions using Plackett–Burman experimental design (PBED) were investigated. Results: The highest increases of laccase (12,382.5 U/mg protein) and MnP (564.1 U/mg protein) activities were seen in co-cultures I3 and I5, respectively, both at 10 d after inoculation. This level of activity was significantly different from the enzyme activity in non-inoculated T. maxima (4881.0 U/mg protein and 291.8 U/mg protein for laccase and MnP, respectively). PBED results showed that laccase was increased (P < 0.05) by high levels of glucose, (NH4)2SO4 and MnSO4 and low levels of KH2PO4, FeSO4 and inoculum (P < 0.05). In addition, MnP activity was increased (P < 0.05) by high yeast extract, MgSO4, CaCl2 and MnSO4 concentrations. Conclusions: Interaction between indigenous fungi: T. maxima–P. carneus improves laccase and MnP activities. The inoculation time of P. carneus on T. maxima plays an important role in the laccase and MnP enhancement. The nutritional requirements for enzyme improvement in a co-culture system are different from those required for a monoculture system

Mulierismo Y teoría social. Un abordaje de los estudios de género desde la crítica de las ciencias sociales

Ante los cambios que han sufrido las ciencias sociales, frente a los ataques feministas en los últimos cuarenta años de desempeño intelectual de grupos muy importantes en los países desarrollados, es necesario analizar en qué si - tuación observamos la efectividad del mulierismo y el feminismo como una confluencia histórica que está mostrando un nuevo paradigma, estructuras, etc., dentro de las ciencias sociales que, primero se convierte en crítica, y luego, en transformaciones de ajustes y cambios, etc., probablemente, nos muestren otros referentes de las relaciones hombre-mujer que se están configurando bajo combinaciones que, seguramente, definirán las futuras construcciones epistémicas que comprenderán las nuevas sociedades. La crítica a las ciencias sociales desde la feminidad es una nueva perspectiva, tanto en la incidencia que tiene en el género, como en los mecanismos de trasgresión y avance en las relaciones sociales entre los sexos