Nanotechnology in agriculture: Current status, challenges and future opportunities

Trace Elements In Terrestrial Environments Biogeochemistry Bioavailability And Risks Of Metals

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Office of Environmental Health Hazard Assessment

This review presents a perspective on the research trends and solutions from recent years in the domain of antimicrobial packaging materials. The antibacterial, antifungal, and antioxidant activities can be induced by the main polymer used for packaging or by addition of various components from natural agents (bacteriocins, essential oils, natural extracts, etc.) to synthetic agents, both organic and inorganic (Ag, ZnO, TiO2 nanoparticles, synthetic antibiotics etc.). The general trend for the packaging evolution is from the inert and polluting plastic waste to the antimicrobial active, biodegradable or edible, biopolymer film packaging. Like in many domains this transition is an evolution rather than a revolution, and changes are coming in small steps. Changing the public perception and industry focus on the antimicrobial packaging solutions will enhance the shelf life and provide healthier food, thus diminishing the waste of agricultural resources, but will also reduce the plastic pollution generated by humankind as most new polymers used for packaging are from renewable sources and are biodegradable. Polysaccharides (like chitosan, cellulose and derivatives, starch etc.), lipids and proteins (from vegetal or animal origin), and some other specific biopolymers (like polylactic acid or polyvinyl alcohol) have been used as single component or in blends to obtain antimicrobial packaging materials. Where the package’s antimicrobial and antioxidant activities need a larger spectrum or a boost, certain active substances are embedded, encapsulated, coated, grafted into or onto the polymeric film. This review tries to cover the latest updates on the antimicrobial packaging, edible or not, using as support traditional and new polymers, with emphasis on natural compounds.

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Biodegradable Antimicrobial Food Packaging: Trends and Perspectives

The world’s human population continues to increase, posing a significant challenge in ensuring food security, as soil nutrients and fertility are limited and decreasing with time. Thus, there is a need to increase agricultural productivity to meet the food demands of the growing population. A high level of dependence on chemical fertilizers as a means of increasing food production has damaged the ecological balance and human health and is becoming too expensive for many farmers to afford. The exploitation of beneficial soil microorganisms as a substitute for chemical fertilizers in the production of food is one potential solution to this conundrum. Microorganisms, such as plant growth-promoting rhizobacteria and mycorrhizal fungi, have demonstrated their ability in the formulation of biofertilizers in the agricultural sector, providing plants with nutrients required to enhance their growth, increase yield, manage abiotic and biotic stress, and prevent phytopathogens attack. Recently, beneficial soil microbes have been reported to produce some volatile organic compounds, which are beneficial to plants, and the amendment of these microbes with locally available organic materials and nanoparticles is currently used to formulate biofertilizers to increase plant productivity. This review focuses on the important role performed by beneficial soil microorganisms as a cost-effective, nontoxic, and eco-friendly approach in the management of the rhizosphere to promote plant growth and yield.

Agricultural Sustainability: Microbial Biofertilizers in Rhizosphere Management

The progressive increase in nanoparticles (NPs) applications and their potential release into the environment because the majority of them end up in the soil without proper care have drawn considerable attention to the public health, which has become an increasingly important area of research. It is required to understand ecological threats of NPs before applications. Once NPs are released into the environment, they are subjected to translocation and go through several modifications, such as bio/geo-transformation which plays a significant role in determination of ultimate fate in the environment. The interaction between plants and NPs is an important aspect of the risk assessment. The plants growing in a contaminated medium may significantly pose a threat to human health via the food chain. Metal oxide NPs ZnO and CuO, the most important NPs, are highly toxic to a wide range of organisms. Exposure and effects of CuO and ZnO NPs on soil biota and human health are critically discussed in this study. The potential benefits and unintentional dangers of NPs to the environment and human health are essential to evaluate and expected to produce less toxic and more degradable NPs to minimize the environmental risk in the future.

ZnO and CuO nanoparticles: a threat to soil organisms, plants, and human health.

The combustion of solid fuel at power plants pollutes adjacent areas with potentially toxic elements (PTEs), which increases risks to public health in the vicinity of these facilities. The proposed paper presents the results of a geochemical study of PTEs (Cr, Mn, Ni, Cu, Zn, Cd, and Pb) contamination in the vicinity of Novocherkassk Power Plant (NPP) as it relates to environmental and human health risks. The impact zone of NPP is pronounced for a distance of approximately 7 km northwest of the enterprise—the second largest coal power plant in Southern Russia. Data from monitoring sites lead us to conclude that spatial patterns of soil pollution are strongly influenced by the peculiarities of local atmospheric circulation, while the characteristics of soils within the study area play a secondary role. The highest levels of PTEs and their exchangeable forms exceed both regional background and sanitary and hygienic standards within a radius of 3 km to the west of the plant, which corresponds to a zone of soils contaminated with Cr, Ni, Cu, Zn, Cd, and Pb. The carcinogenic risk to human health slightly exceeds the permissible standard of 1 × 10−6 for soils in close vicinity of the enterprise due to the potential human intake of Ni, Cd, and Pb. The results of the health risk assessment indicate no noncarcinogenic risks for adults, while for children, they are low.

Environmental and human health risk assessment of potentially toxic elements in soils around the largest coal-fired power station in Southern Russia.

The effects of bulk- and nano-CuO were monitored on barley (Hordeum sativum L.) in hydroponic conditions. The anatomical and cyto-/morphometric parameters of plants, exposed to both types of CuO in different doses (300 and 2000 mg/L) were recorded. The germination rate, root and shoot lengths decreased in a dose-dependent manner. Exposure to nano-CuO significantly increased Cu content in the H. sativum roots; however, the translocation rates of dissolved Cu were low and showed less accumulation in above-ground tissues. The differences between nano- and bulk-CuO treated plants were sufficiently evident, but at lower concentrations, these differences were non-significant. The relative seed germination inhibition was noted up to 11% and 22% under the high dose of bulk- and nano-CuO, respectively; however, at low dose, it was non-significant. The relative root length was reduced 3.6 fold by bulk- and 1.5 fold by nano-CuO, and shoot lengths decreased 1.6 fold by bulk- and 1.4 fold by nano-CuO under the high dose after growth of 30 days. It indicated more morphological effects on H. sativum caused by bulk- than the nano-CuO. The cytomorphometric analysis indicated the average cortex cell, total cortex, and total central cylinder areas of root cells and the average areas of chlorenchyma leaf cells were increased as compared to control in both bulk- and nano-CuO treated plants. It showed destructive effects of nano- and bulk-CuO on cellular organizations of H. sativum anatomy. Thus, at the low dose, the minimal effects of nano-CuO were observed than the bulk. Therefore, the finding could be interest for the safe application of nano-CuO.

Assessing the toxicity and accumulation of bulk- and nano-CuO in Hordeum sativum L

The existing unique solution of a system of equations describing motion along a given trajectory in the space of variables is considered when the vector function meets the conditions of the Cauchy problem. The stability of those functions that are positive everywhere except for the equilibrium position is estimated. The stability of linear autonomous systems is determined by the roots of the characteristic equation of the matrix. 

Alexey Maksimov

Papers

ZnO and CuO nanoparticles: a threat to soil organisms, plants, and human health.

Environmental and human health risk assessment of potentially toxic elements in soils around the largest coal-fired power station in Southern Russia.

Assessing the toxicity and accumulation of bulk- and nano-CuO in Hordeum sativum L

Mathematical Problem of the Stability Theory of the Gas Diesel Transport Control System