Phytoremediation is an attractive strategy for cleaning soils polluted with a wide spectrum of organic and inorganic toxic compounds. Among these pollutants, heavy metals have attracted global ...attention due to their negative effects on human health and terrestrial ecosystems. As a result of this, numerous studies have been carried out to elucidate the mechanisms involved in removal processes. These studies have employed many plant species that might be used for phytoremediation and the obtention of end bioproducts such as biofuels and biogas useful in combustion and heating. Phytotechnologies represent an attractive segment that is increasingly gaining attention worldwide due to their versatility, economic profitability, and environmental co-benefits such as erosion control and soil quality and functionality improvement. In this review, the process of valorizing biomass from phytoremediation is described; in addition, relevant experiments where polluted biomass is used as feedstock or bioenergy is produced via thermo- and biochemical conversion are analyzed. Besides, pretreatments of biomass to increase yields and treatments to control the transfer of metals to the environment are also mentioned. Finally, aspects related to the feasibility, benefits, risks, and gaps of converting toxic-metal-polluted biomass are discussed.
Los recientes desarrollos en el campo de la nanotecnología han traído nuevas oportunidades para la innovación y el avance en un número sustancial de disciplinas, entre las que destaca la agricultura. ...Los porcentajes actuales de inanición en todo el mundo, junto con el crecimiento constante de la población, combinados con los problemas ambientales causados por la erosión y el uso de productos químicos, han puesto en primer plano la necesidad de mejoras sostenibles en la práctica agrícola, que podrían atenderse empleando nanomateriales (NMs). Los NMs se presentan como un sustituto atractivo de los materiales convencionales, debido a sus atributos y la mejora que estos representan. Los pesticidas y fertilizantes son dos de los muchos productos que han demostrado tener un gran potencial cuando se producen a nivel nanométrico, mostrando gran eficiencia en la liberación dirigida y controlada de agroquímicos, lo que se traduce en una mayor efectividad biológica, al lograr, en general, un aumento en el rendimiento y la productividad de los cultivos. No obstante, aun existen aspectos desconocidos relacionados con los efectos de la nanotecnología, por ejemplo, existe un conocimiento limitado sobre la bioseguridad, los efectos adversos, el destino y la reactividad biológica de los nanomateriales una vez que se introducen en el medio ambiente. El daño que pueden causar, no solo a los agroecosistemas, sino también a la salud humana y al medio ambiente, aún no se comprende completamente, a pesar de los numerosos esfuerzos científicos que se han realizado para evaluar el peligro intrínseco que pueden causar los NMs. Esta revisión busca servir como marco referencial al estado de la nanotecnología en la agricultura: desarrollos, aplicaciones y riesgos conocidos. Se revisan las características de los NMs aplicados en agricultura, junto con los resultados obtenidos de las pruebas de comportamiento y destino con respecto a las especies vegetales. Finalmente, se analizan las interacciones reportadas entre los componentes bióticos y abióticos de los ecosistemas expuestos, presentando un estudio sobre el estado y la dirección de la nanoagricultura.
In this article, the geographical location and availability of the most important crop residues generated in Mexico over the last 10 years (2008—2017) were determined. This study estimates the gross ...number of residues for the four most important cultivars in Mexico named conventional residues (CRs) such as corn, wheat, sorghum, and barley, and estimates were also made for regionally important crops identified as nonconventional residues (NCRs) such as coffee, sugarcane, and beans. The total and sustainable energy potentials (TEP and SEP) for agricultural residues were calculated, in similar way the butanol and electricity production potentials were also calculated if these residues were processed under a nonconventional biorefinery scheme; the calculated availability of crop residues was 59,059,666 t/year, thus demonstrating that Mexico could have great potential for bioenergy production. The estimated TEP was 1,787,241,249 PJ/year, and the SEP was 78,724,689 PJ/year. The production of butanol and its production cost were calculated for the main crop residues; the butanol volume ranged from 7348 to 161,610 t/day, and the volume of crops of regional importance ranged from 6461.9 to 151,389 t/day. The minimum butanol production cost was 2000 t/day of feedstock. The surplus electricity was determined for all crop residues.
Entophytic bacteria (EBs) are very diverse and found in virtually all plant species studied. These natural EBs live insides the host plant and can be used to maximize crop and fruit yield by ...exploiting their potential. In this paper, EBs characterization from various citrus genotypes andtheir influence on the morphological and physiological functioning of sour orange (Citrus aurantium) seedlings are described. To assess the influence of 10 distinct EBs, three different techniques (injection, soil mix, and spray) were applied for single and mixed inoculation on sour orange (C. aurantium) seedlings. The selected strains were identified as firmicutes (Enterococcus faecalis, Bacillus safensis, Bacillus cereus, Bacillus megaterium, Brevibacillus borstelensis &Staphylococcus haemolyticus), and gamma Proteobacteria (Enterobacter hormachaei, Proteus mirabilis, Pseudomonas aeruginosa, &Pseudomonas sp.) by 16S rRNA gene sequencing. To investigate the influence of these EBs on host plant morphology, different parameters (morphometric) were recorded after five WOI (weeks of inoculation), including shoot/root length, shoot/root fresh and dry biomass, and biophysical analyses i.e., relative water content (RLWC). Physiological markers such as chlorophyll & carotenoid content, protein content, proline content, phenolics, and flavonoids were also analyzed to determine the influence of endophytes on sour orange seedlings. Five strains such as SM-34, SM-20, SM-36, SM-68, and SM-56 significantly improved the development and physiology of sour orange seedlings. Bacillus cereus and Pseudomonas aeruginosa produced the best outcomes in terms of plant growth. The relative quantification of bacterial inoculums was determined using real-time PCR. A rise in the number of bacterial cells in inoculated treatment suggests that bacterial strains survived and colonized successfully, and also shown their competitiveness with native bacterial community structure. As per the results of inoculation methods,soil mixing, and injection methods were determined to be effective for bacterial inoculation to plants but a variable trend was found for different parameters with test bacterial strains. After testing their impact on field conditions, these strains can be applied as fertilizers as an alternative to conventional chemical fertilizer, although in the context of mixed inoculation of bacterial strains, 5 M and 6 M performed best andenhancedplant growth-promoting activity.
Sorghum is cultivated in tropical and subtropical regions of the world and is an important cereal for Mexico. However, it is affected by different pests, especially the yellow aphid. The objective of ...the research was to evaluate the effectiveness of biological, botanical and chemical insecticides in reducing Melanaphis sacchari populations in sorghum plants under greenhouse conditions. Planting was conducted in a greenhouse, using the sorghum hybrid 945-M. Pests, diseases and weeds management were implemented. The incidence of the yellow aphid was induced artificially. A total of 13 treatments were applied. The following variables were assessed: the number of aphids per leaf, the biological effectiveness of the treatments, plant height, diameter of the plant stem, number of leaves, and the weight of fresh and dry plants. An analysis of variance was conducted for each variable under study, as along with a comparison of means using the Tukey method (α=0.05) and correlation analysis using the SAS® 9.4 software. The chemical, biological and organic insecticide that exhibited the greatest control of the yellow aphid (more than 95%) were: Toretto® (sulfoxaflor), PHC® Meta Tron® (M. anisopliae), Bio-Die® (Argemonin, Berberine, Ricinin and a-Terthienyl). Adequate management strategies are needed to avoid health problems in people, environmental contamination and resistance or multiple resistance.
Engineered nanomaterials (ENMs) form the basis of a great number of commodities that are used in several areas including energy, coatings, electronics, medicine, chemicals and catalysts, among ...others. In addition, these materials are being explored for agricultural purposes. For this reason, the amount of ENMs present as nanowaste has significantly increased in the last few years, and it is expected that ENMs levels in the environment will increase even more in the future. Because plants form the basis of the food chain, they may also function as a point-of-entry of ENMs for other living systems. Understanding the interactions of ENMs with the plant system and their role in their potential accumulation in the food chain will provide knowledge that may serve as a decision-making framework for the future design of ENMs. The purpose of this paper was to provide an overview of the current knowledge on the transport and uptake of selected ENMs, including Carbon Based Nanomaterials (CBNMs) in plants, and the implication on plant exposure in terms of the effects at the macro, micro, and molecular level. We also discuss the interaction of ENMs with soil microorganisms. With this information, we suggest some directions on future design and areas where research needs to be strengthened. We also discuss the need for finding models that can predict the behavior of ENMs based on their chemical and thermodynamic nature, in that few efforts have been made within this context.
•Future ENMs design should consider surface properties.•Particle size should be considered in chemically stable ENMs.•In future design of CBNMs, inclusion of bioactive functional groups is suggested.•Models considering ENMs chemical and thermodynamic nature are needed.
Sotol (Dasylirion spp.) is a plant endemic to northern Mexico used since ancient times by North American Indians. In the present research, we studied the transformation of lignocellulosic Sotol ...Bagasse (SB) components as a feedstock for bioethanol 2G production. For this purpose, SB was pretreated with diluted acid (AP) and alkali (BP). In AP, biomass was exposed to different acid concentrations and reactions proceeded at different times according to a 32 experimental design. BP was performed by stirring SB with a 3 M NaOH solution at 30 °C and 120 rpm for 6 h. Pretreated samples were hydrolyzed using the Cellic CTec2® enzyme complex. These experiments were performed at the micro-level. Two conditions presented the best performance: AP1 (0.5% v/v acid; 15 min; 121 °C) and AP2 (1% v/v acid; 30 min; 121 °C). Then, AP1 and AP2 were selected for process scale-up, resulting in RS yields of 22.4% and 19.46%, respectively. The sugars produced were fermented in presence of Kluyveromyces marxianus producing an 81.85% ethanol yield. Data indicated that fermentation of SB treated with AP1 produced ethanol. In addition, fermentation of SB pretreated with AP2 generated ethanol and low concentrations of iso-butanol, acetaldehyde, and isoamyl alcohol. Ethanol and energy yield of AP1 treated biomass were 0.19 L bioethanol and 4.09 MJ per kg SB. These results proved that the proposed process is sustainable and can potentially be used for bioethanol 2G production using SB. As a result, circular bioeconomy will be stimulated.
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•Microscale reactions provide fast results useful in decision-making.•Surplus energy was generated by the new process.•SB showed a significant potential to produce ethanol 2G.
Green synthesis (GS), referred to the synthesis using bioactive agents such as plant materials, microorganisms, and various biowastes, prioritizing environmental sustainability, has become ...increasingly relevant in international scientific practice. The availability of plant resources expands the scope of new exploration opportunities, including the evaluation of new sources of organic extracts, for instance, to the best of our knowledge, no scientific articles have reported the synthesis of zinc oxide nanoparticles (ZnO NPs) from organic extracts of
T. recurvata
, a parasitic plant very common in semiarid regions of Mexico.
This paper presents a greener and more efficient method for synthesizing ZnO NPs using
T. recurvata
extract as a reducing agent. The nanoparticles were examined by different techniques such as UV–vis spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and BET surface analysis. The photocatalytic and adsorptive effect of ZnO NPs was investigated against methylene blue (MB) dye in aqueous media under sunlight irradiation considering an equilibrium time under dark conditions. ZnO nanoparticles were highly effective in removing MB under sunlight irradiation conditions, showing low toxicity towards human epithelial cells, making them promising candidates for a variety of applications. This attribute fosters the use of green synthesis techniques for addressing environmental issues.
This study also includes the estimation of the supported electric field distributions of ZnO NPs in their individual spherical or rounded shapes and their randomly oriented organization, considering different diameters, by simulating their behavior in the visible wavelength range, observing resonant enhancements due to the strong light-matter interaction around the ZnO NPs boundaries.
Mole sauce is one of the traditional Mexican foods; it is a complex mixture of ingredients of diverse origins that directly influence its nutritional value. The objective of this study was to ...investigate the antioxidant properties and nutritional components in five varieties of mole from Hidalgo in Mexico namely verde (V), ranchero (R), almendrado (A), casero (C), and pipian (P). Proximal chemical analysis and determination of the color index and the content of total starch, dietary fiber, mineral content (Ca, Na, K, and Mg), total phenolic content, and antioxidant activity by ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2-diphenylpicrylhydrazyl) were carried out. All the five varieties of mole reported less than 25% moisture content while fat content varied from 42.9% to 58.25%. The color index ranged from a deep orange to a deep red color. A fair percentage of dietary fiber was found in all mole varieties with a low amount of starch as well. The presence of mostly insoluble dietary fiber, high phenolic content (36.13-79.49 mg GAE/100 g), and high antioxidant activity could be considered important strengths to boost the consumption of these traditional preparations. This research will contribute to a better scientific knowledge of traditional Mexican sauces as functional foods or nutraceuticals that could be used to avoid health disorders.
Bacteria and yeast are being intensively used to produce biofuels and high-added-value products by using plant biomass derivatives as substrates. The number of microorganisms available for industrial ...processes is increasing thanks to biotechnological improvements to enhance their productivity and yield through microbial metabolic engineering and laboratory evolution. This is allowing the traditional industrial processes for biofuel production, which included multiple steps, to be improved through the consolidation of single-step processes, reducing the time of the global process, and increasing the yield and operational conditions in terms of the desired products. Engineered microorganisms are now capable of using feedstocks that they were unable to process before their modification, opening broader possibilities for establishing new markets in places where biomass is available. This review discusses metabolic engineering approaches that have been used to improve the microbial processing of biomass to convert the plant feedstock into fuels. Metabolically engineered microorganisms (MEMs) such as bacteria, yeasts, and microalgae are described, highlighting their performance and the biotechnological tools that were used to modify them. Finally, some examples of patents related to the MEMs are mentioned in order to contextualize their current industrial use.
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