Nanoscale copper in the soil-plant system - toxicity and underlying potential mechanisms (original) (raw)
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Ecotoxicity of as-synthesised copper nanoparticles on soil bacteria
IET nanobiotechnology, 2021
Release of metallic nanoparticles in soil poses a serious threat to the ecosystem as they can affect the soil properties and impose toxicity on soil microbes that are involved in the biogeochemical cycling. In this work, in vitro ecotoxicity of as-synthesised copper nanoparticles (CuNPs) on Bacillus subtilis (MTCC No. 441) and Pseudomonas fluorescens (MTCC No. 1749), which are commonly present in soil was investigated. Three sets of colloidal CuNPs with identical physical properties were synthesised by chemical reduction method with per batch yield of 0.2, 0.3 and 0.4 gm. Toxicity of CuNPs against these soil bacteria was investigated by MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), cytoplasmic leakage and ROS (reactive oxygen species) assay. MIC of CuNPs were in the range of 35-60 µg/ml and 35-55 µg/ml for B. subtilis and P. fluorescens respectively, while their MBC ranged from 40-70 µg/ml and 40-60 µg/ml respectively. MIC and MBC tests reveal tha...
Biosynthesis and effects of copper nanoparticles on plants
Environmental Chemistry Letters, 2017
Copper nanoparticles have improved properties compared to the bulk copper material. Copper nanoparticles indeed find applications in gas sensors, heat transfer fluids, catalysis, solar energy and batteries. Antibacterial and antifungal activities of copper nanoparticles find applications in the agriculture and healthcare sectors. Nonetheless, careless use of copper nanoparticles may cause environmental pollution and health effects. Here we review the biosynthesis of copper nanoparticles using plant materials, named phytosynthesis, and microorganisms. We also discuss the effect of copper nanoparticles on crops and pathogenic microorganisms. Copper nanoparticles varying in sizes from 5 to 295 nm have been synthesized using leaf extracts and latex from plants, and using bacteria and fungi. Biosynthesized copper nanoparticles show good antimicrobial activity inhibiting the growth of pathogenic bacteria and pathogenic fungi. Copper nanoparticles enhance the germination and growth of some plants at lower concentrations, whereas high concentrations result in retarded growth.
Long-term effects of Cu(OH)2 nanopesticide exposure on soil microbial communities
Environmental Pollution, 2021
Copper-based (nano)pesticides in agroecosystems may result in unintended consequences on non-target soil microbial communities, due to their antimicrobial broad spectrum. We studied the impact of a commercial Cu(OH) 2-nanopesticide, over 90 days, at single and season agricultural application doses, in the presence and absence of an edaphic organism (the isopod Porcellionides pruinosus), on microbial communities' function, structure and abundance. Results were compared to the effects of Cu(OH) 2-ionic. The nanopesticide application resulted in significant changes on both bacterial and fungal communities' structure, particularly at the season application. The exposed bacterial community presented a significantly lower richness, and higher diversity and evenness while the exposed fungal community presented lower diversity and richness. At the functional level, a significant increase on microbial ability of carbon utilization and a significant decrease on the bÀglucosidase activity was observed for communities exposed to the nanopesticide. Regarding Cu forms, less pronounced effects were observed in soils spiked with Cu(OH) 2-ionic, which might result from lower Cu concentration in porewater. The presence of P. pruinosus did not induce significant changes in diversity indexes (fungal community) and communitylevel physiological profiling, suggesting an attenuation of the nanopesticide effect. This study revealed that Cu(OH) 2-nanopesticide, at doses applied in agriculture, impact the soil microbial community, possibly affecting its ecological role. On the other hand, invertebrates may attenuate this effect, highlighting the importance of jointly including different interacting communities in the risk assessment of nanopesticides in soils.
Environmental Toxicology and Chemistry, 2008
Because of their insolubility in water, nanoparticles have a limitation concerning toxicity experiments. The present study demonstrated a plant agar test for homogeneous exposure of nanoparticles to plant species. The effect of Cu nanoparticles on the growth of a plant seedling was studied, and bioaccumulation of nanoparticles was investigated. All tests were conducted in plant agar media to prevent precipitation of water-insoluble nanoparticles in test units. The plant species were Phaseolus radiatus (mung bean) and Triticum aestivum (wheat). Growth inhibition of a seedling exposed to different concentrations of Cu nanoparticles was examined. Copper nanoparticles were toxic to both plants and also were bioavailable. The 2-d median effective concentrations for P. radiatus and T. aestivum exposed to Cu nanoparticles were 335 (95% confidence level, 251-447) and 570 (450-722) mg/L, respectively. Phaseolus radiatus was more sensitive than T. aestivum to Cu nanoparticles. A cupric ion released from Cu nanoparticles had negligible effects in the concentration ranges of the present study, and the apparent toxicity clearly resulted from Cu nanoparticles. Bioaccumulation increased with increasing concentration of Cu nanoparticles, and agglomeration of particles was observed in the cells using transmission-electron microscopy-energy-dispersive spectroscopy. The present study demonstrated that the plant agar test was a good protocol for testing the phytotoxicity of nanoparticles, which are hardly water soluble.
Influences of Copper Forms on the Toxicity to Microorganisms in Soils
Ecotoxicology and Environmental Safety, 1999
Soil samples with wide ranges of pH (4.9 to 8.1), organic carbon (0.1 to 77%), and total Cu contents from 32 to 11700 mg kg ؊1 , collected near a copper mine, were used to investigate the relationships between microbial features and Cu speciation in order to clarify the form(s) of Cu adversely a4ecting microorganisms. The e4ects of Cu on soil microorganisms were evaluated by two indicators: the ratio of microbial biomass carbon to soil organic carbon (C mic /Org-C) and Cu tolerance level of bacterial community (IC 50). The sequential extraction scheme of McLaren and Crawford (1973) was used to quantify the di4erent Cu forms (soluble and exchangeable, speci5cally adsorbed, and organically bound). These in6uences were investigated using simple correlation analysis, multiple regression analysis, and principal component analysis. The IC 50 was positively correlated with the log concentration of soluble and exchangeable Cu (Ex-Cu) (r ؍ 0.757, P < 0.01). The IC 50 value was also in6uenced by the amount of speci5cally adsorbed Cu. The C mic /Org-C ratio was not signi5cantly correlated with any Cu forms. Thus, other soil properties had more in6uence on the size of microbial biomass carbon in the soils used. The amount of Ex-Cu exerting high toxicity was a4ected by pH and the amount of total Cu.
In vitro effects of copper nanoparticles on plant pathogens, beneficial microbes and crop plants
Spanish Journal of Agricultural Research
Copper-based chemicals are effectively used as antimicrobials in agriculture. However, with respect to its nanoparticulate form there has been limited number of studies. In this investigation, in vitro tests on effect of copper nanoparticles (CuNPs) against plant pathogenic fungi, oomycete, bacteria, beneficial microbes Trichoderma harzianum and Rhizobium spp., and wheat seeds were conducted. Integration of CuNPs with non-nano copper like copper oxychloride (CoC) at 50 mg/L concentration each recorded 76% growth inhibition of the oomycete Phytophthora cinnamomi in vitro compared to the control. CuNPs also showed synergistic inhibitory effect with CoC on mycelial growth and sporulation of A. alternata. Pseudomonas syringae was inhibited at 200 mg/L of CuNPs. CuNPs were not significantly biocidal against Rhizobium spp. and Trichoderma harzianum compared to CoC. Evaluation of the effect of CuNP on wheat revealed that rate of germination of wheat seeds was higher in presence of CuNPs an...
Are Copper Nanoparticles Toxic to All Plants? A Case Study on Onion (Allium cepa L.)
Agronomy , 2021
Sandy soils with high alkalinity are characterized by low copper (Cu) contents that lead to many deficiency symptoms in plants. Cu deficiency in plants can be corrected using several cheap Cu sources. Nevertheless, the effects that novel sources, such as Cu nanoparticles (NPs), have on plants remain poorly studied. In the present work, we investigated the effect and efficiency of Cu supplementation to onion (Allium cepa L.) plants using Cu sulfate, chelate, or NPs, and compared their effects on bulb quality, yield, and contents of phytochemicals. Two successive seasons (2018/2019 and 2019/2020) of field experiments were conducted in newly reclaimed sandy soils, where plants were sprayed with either 10 ppm CuO NPs, 20 ppm CuSO4 ·5H2O, or 20 ppm of Cu chelates. Overall, Cu deficiency (control) resulted in a significant decrease in yield and all quality traits of onion plants. CuO NPs treatment significantly enhanced growth parameters, including plant height, number of leaves, fresh and dry weight, yield, and bulb quality, compared with Cu sulfate and chelates. This was also the case regarding chemical constituents such as macro- and micro-nutrients, total soluble solids, phytochemical compounds, vitamins, and amino acids. Although Cu sulfate is the cheapest form used for Cu supplementation, results of the present study suggest that CuO NPs was not only safe to use, but also was the treatment that led to the highest onion yield and quality.
Bactericides Based on Copper Nanoparticles Restrain Growth of Important Plant Pathogens
Pathogens
Copper nanoparticles (CuNPs) can offer an alternative to conventional copper bactericides and possibly slow down the development of bacterial resistance. This will consequently lower the accumulation rate of copper to soil and water and lower the environmental and health burden imposed by copper application. Physical and chemical methods have been reported to synthesize CuNPs but their use as bactericides in plants has been understudied. In this study, two different CuNPs products have been developed, CuNP1 and CuNP2 in two respective concentrations (1500 ppm or 300 ppm). Both products were characterized using Dynamic Light Scattering, Transmission Electron Microscopy, Attenuated Total Reflection measurements, X-ray Photoelectron Spectroscopy, X-ray Diffraction and Scattering, and Laser Doppler Electrophoresis. They were evaluated for their antibacterial efficacy in vitro against the gram-negative species Agrobacterium tumefaciens, Dickeya dadantii, Erwinia amylovora, Pectobacterium...