Effect of Multi-walled Carbon Nanotubes and Manganese and Zinc Doped Ferrites on the Development of Capsicum annuum

Nanotechnology applied to agriculture (nanoagriculture) represents a watershed in the study and development of novel alternatives that could strongly influence agricultural practices. In this research, we documented the comparative study with multi-walled carbon nanotube (MWCNT) and ferrites doped with zinc-manganese in C. annuum development, due to the nanoparticles study in plant crops has been showing beneficial effects.

Synthetic Multi-walled Carbon Nanotubes Affect Arabidopsis thaliana Growth through Blocking the TOR Signaling Pathway

The phytotoxicity of synthetic multi-walled carbon nanotubes (MWCNTs) on plant growth has been documented. However, the physiological mechanisms associated with it are not clear. The activity of TOR signaling pathway and phytoregulators balance play key roles in plant growth regulation and their stress response.

Bioelimination of Phytotoxic Hydrocarbons by Biostimulation and Phytoremediation of Soil Polluted by Waste Motor Oil

Soils contaminated by waste motor oil (WMO) affect their fertility, so it is necessary to recover them by means of an efficient and safe bioremediation technique for agricultural production. The objectives were: (a) to biostimulate the soil impacted by WMO by applying crude fungal extract (CFE) and Cicer arietinum as a green manure (GM), and (b) phytoremediation using Sorghum vulgare with Rhizophagus irregularis and/or Rhizobium etli to reduce the WMO below the maximum value according to NOM-138 SEMARNAT/SS or the naturally detected one. Soil impacted by WMO was biostimulated with CFE and GM and then phytoremediated by S. vulgare with R. irregularis and R. etli. The initial and final concentrations of WMO were analyzed. The phenology of S. vulgare and colonization of S. vulgaris roots by R. irregularis were measured. The results were statistically analyzed by ANOVA/Tukey's HSD test. The WMO in soil that was biostimulated with CFE and GM, after 60 days, was reduced from 34,500 to 2066 ppm, and the mineralization of hydrocarbons from 12 to 27 carbons was detected. Subsequently, phytoremediation with S. vulgare and R. irregularis reduced the WMO to 86.9 ppm after 120 days, which is a concentration that guarantees the restoration of soil fertility for safe agricultural production for human and animal consumption.

Biorecovery of Agricultural Soil Impacted by Waste Motor Oil with Phaseolus vulgaris and Xanthobacter autotrophicus

Agricultural soil contamination by waste motor oil (WMO) is a worldwide environmental problem. The phytotoxicity of WMO hydrocarbons limits agricultural production; therefore, Mexican standard NOM-138-SEMARNAT/SSA1-2012 (NOM-138) establishes a maximum permissible limit of 4400 ppm for hydrocarbons in soil. The objectives of this study are to (a) biostimulate, (b) bioaugment, and (c) phytoremediate soil impacted by 60,000 ppm of WMO, to decrease it to a concentration lower than the maximum allowed by NOM-138. Soil contaminated with WMO was biostimulated, bioaugmented, and phytoremediated, and the response variables were WMO concentration, germination, phenology, and biomass of Phaseolus vulgaris. The experimental data were validated by Tukey HSD ANOVA. The maximum decrease in WMO was recorded in the soil biostimulated, bioaugmented, and phytoremediated by P. vulgaris from 60,000 ppm to 190 ppm, which was considerably lower than the maximum allowable limit of 4400 ppm of NOM-138 after five months. Biostimulation of WMO-impacted soil by detergent, mineral solution and bioaugmentation with Xanthobacter autotrophicus accelerated the reduction in WMO concentration, which allowed phytoremediation with P. vulgaris to oxidize aromatic hydrocarbons and recover WMO-impacted agricultural soil faster than other bioremediation strategies.

Ligninolytic activity of the Penicillium chrysogenum and Pleurotus ostreatus fungi involved in the biotransformation of synthetic multi-walled carbon nanotubes modify its toxicity

Multi-walled carbon nanotubes (MWCNTs) are of multidisciplinary scientific interest due to their exceptional physicochemical properties and a broad range of applications. However, they are considered potentially toxic nanoparticles when they accumulate in the environment. Given their ability to oxidize resistant polymers, mycorremediation with lignocellulolytic fungi are suggested as biological alternatives to the mineralization of MWCNTs. Hence, this study involves the ability of two fungi specie to MWCNTs biotransformation by laccase and peroxidases induction and evaluation in vivo of its toxicity using Caenorhabditis elegans worms as a model. Results showed that the fungi Penicillium chrysogenum and Pleurotus ostreatus were capable to grow on media with MWCNTs supplemented with glucose or lignin. Activities of lignin-peroxidase, manganese-peroxidase, and laccase in cultures of both fungi were induced by MWCNTs. Raman, FTIR spectroscopy, HR-TEM, and TGA analyses of the residue from the cultures of both fungi revealed structural modifications on the surface of MWCNTs and its amount diminished, correlating the MWCNTs structural modifications with the laccase-peroxidase activities in the fungal cultures. Results indicate that the degree of toxicity of MWCNTs on the C. elegans model was enhanced by the structure modification associated with the fungal ligninolytic activity. The toxic effect of MWCNTs on the in vivo model of worms reveals the increment of reactive oxygen species as a mechanism of toxicity. Findings indicate that the MWCNTs can be subject in nature to biotransformation processes such as the fungal metabolism, which contribute to modify their toxicity properties on susceptible organisms and contributing to environmental elimination.

Estudio del sistema de producción de café (Coffea arabica L.) en la región Frailesca, Chiapas

Las zonas cafetaleras del estado de Chiapas se caracterizan por sus contrastes ambientales, técnicos, económicos y socioculturales, que influyen en la producción del grano. El objetivo de este estudio fue analizar la intervención del componente humano en el sistema de producción de café (Coffea arabica L.), específicamente en los aspectos de manejo del cultivo, ambientales y socioeconómicos en la región Frailesca, del estado chiapaneco. Para ello, se aplicaron 243 encuestas a los involucrados en la producción de café. Se identificó la necesidad de impulsar la tecnificación del cultivo, carencia de infraestructura adecuada para la atención del proceso de beneficiado del café y mal manejo de la plantación, poca o nula organización de los productores para facilitar la consecución de créditos accesibles, falta de asesoría técnica para la transformación de la producción de café convencional a café orgánico, conservación delsuelo y manejo adecuado del agua en beneficio húmedo. La identificación de estas dificultades para hacer rentable el cultivo de café permiten planificar el manejo del sistema de producción de café y con ello satisfacer las exigencias del mercado en términos de calidad e inocuidad. Archivo XML (SciELO)

Production of short-chain fatty acids from the biodegradation of wheat straw lignin by Aspergillus fumigatus

The wheat straw lignin-rich fraction (WSLig-RF) can be used as a raw material for the production of metabolites for industrial use if ligninolytic mitosporic fungi are used for its biodegradation into aromatics and short-chain fatty acids (SCFAs, i.e., SCFA2-6). Although methods for the production of SCFA2-6 have been described previously, quantitative data of SCFA2-6 production have not been reported. The objectives of this study were to investigate the biodegradation of different concentrations of WSLig-RF by Aspergillus fumigatus and to identify whether SCFA2-6 production was dependent on the concentration of aromatics. A. fumigatus generated 2805mgL(-1) acetic acid when mixed with WSLig-RF at a concentration of 20gL(-1). Thus, aromatics are a substrate for the biosynthesis of SCFA2-6, and their production depends on the concentration of WSLig-RF aromatics.

Inconsistencies and ambiguities in calculating enzyme activity: The case of laccase

Laccase is a key enzyme in the degradation of lignin by fungi. Reports indicate that the activity of this enzyme ranges from 3.5 to 484,000 U L(-1). Our aim was to analyze how laccase activity is calculated in the literature, and to determine statistically whether variations in activity are due to biological properties or to inconsistencies in calculation. We found a general lack of consensus on the definition of enzyme activity, and enzymes are sometimes characterized in terms of reaction rate and specific activity. Moreover, enzyme activity is calculated using at least seven different equations. Therefore, it is critical to standardize the calculation of laccase activity in order to compare results directly.

Biorremediación de suelo contaminado con 75000 ppm de aceite residual automotriz por bioestimulación y fitorremediación con Sorghum vulgare y Bacillus cereus y/ o Burkholderia cepacia

En el suelo contaminado en alta concentración de aceite residual automotriz (ARA) causa pérdida de su fertilidad. Una solución es la biorremediación (BR) por doble y secuencial bioestimulación (BS) y posterior fitorremediación (FR) con Sorghum vulgare y Bacillus cereus/Burkholderia cepacia o bacterias promotoras de crecimiento vegetal (BPCV) para reducir el ARA remanente. Los objetivos de este trabajo fueron: a) biorremediar un suelo contaminado con 75000 ppm de ARA por doble y secuencial bioestimulación, y posterior b) fitorremediación con S. vulgare y las BPCV. El suelo contaminado con ARA se biorremedio por BS primero con solución mineral (SM), una segunda BS con Phaseolus vulgaris y BPCV incorporada como abono verde (AV), después por fitorremediación con S. vulgare y las BPCV para minimizar el ARA. Los resultados indicaron que la biorremediación del suelo por doble y secuencial BS: con SM el ARA decreció a 32500 ppm/30 días y con P. vulgaris; lo disminuyo hasta 10100 ppm/90 días. Su fitorremediación para minimizar el ARA remanente con S. vulgare y BPCV a floración lo redujo de 2500 ppm a 800 ppm. Ello apoya que biorestaurar un suelo impactado con elevada concentración de ARA; la mejor es la integración de la BR/FR, que su aplicación por separado.