scholarly journals Effects of silver-graphene oxide on seed germination and early growth of crop species

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8387
Author(s):  
Min-Ji Kim ◽  
Woong Kim ◽  
Haegeun Chung
Keyword(s):  
Graphene Oxide ◽  
Seed Germination ◽  
Antimicrobial Agents ◽  
Germination Rate ◽  
Early Growth ◽  
Trophic Levels ◽  
Dependent Manner ◽  
Crop Species ◽  
Concentration Dependent Manner ◽  
The Impact

Due to its excellent material properties, silver-graphene oxide (Ag-GO) is being studied for diverse applications, such as antimicrobial agents, catalysts and absorbents. Such use of Ag-GO may lead to its release into terrestrial ecosystems, but little is known about the impact of Ag-GO on plants. In the present study, we determined the effects of Ag-GO on seed germination and early growth of crop species by analyzing the germination rate, growth of roots and shoots, hydrogen peroxide (H2O2) accumulation, and the uptake of Ag in alfalfa, radish and cucumber treated with 0.2–1.6 mg mL−1 of Ag-GO. Ag-GO treatment increased the shoot growth of radish at 0.2–1.6 mg mL−1 but decreased that of cucumber at 0.8 mg mL−1. In addition, Ag-GO enhanced the root elongation of radish at 0.2 mg mL−1 but inhibited that of alfalfa at 0.2, 0.8 and 1.6 mg mL−1. Ag-GO treatment induced H2O2 production in alfalfa, radish and cucumber in a concentration-dependent manner. Larger amounts of Ag accumulated in the seedlings as the concentration of Ag-GO increased, and such accumulation suggests that Ag may be transferred to higher trophic levels when plants are exposed to Ag-GO in ecosystems. Our study can, thus, serve as an important basis for setting guidelines for the release of nanomaterials into the environment.

scholarly journals Interaction of Graphene Oxide Modified with Linear and Branched PEG with Monocytes Isolated from Human Blood

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 126
Author(s):  
Pavel Khramtsov ◽  
Maria Bochkova ◽  
Valeria Timganova ◽  
Anton Nechaev ◽  
Sofya Uzhviyuk ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Immune Cells ◽  
Human Peripheral Blood ◽  
Oxide Surface ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Composition And Structure ◽  
Luminescent Signal ◽  
Ros Formation ◽  
The Impact

Multiple graphene-based therapeutics have recently been developed, however potential risks related to the interaction between nanomaterials and immune cells are still poorly understood. Therefore, studying the impact of graphene oxide on various populations of immune cells is of importance. In this work, we aimed to investigate the effects of PEGylated graphene oxide on monocytes isolated from human peripheral blood. Graphene oxide nanoparticles with lateral sizes of 100–200 nm and 1–5 μm were modified with linear and branched PEG (GO-PEG). Size, elemental composition, and structure of the resulting nanoparticles were characterized. We confirmed that PEG was successfully attached to the graphene oxide surface. The influence of GO-PEG on the production of reactive oxygen species (ROS), cytokines, phagocytosis, and viability of monocytes was studied. Uptake of GO-PEG by monocytes depends on PEG structure (linear or branched). Branched PEG decreased the number of GO-PEG nanoparticles per monocyte. The viability of monocytes was not altered by co-cultivation with GO-PEG. GO-PEG decreased the phagocytosis of Escherichia coli in a concentration-dependent manner. ROS formation by monocytes was determined by measuring luminol-, lucigenin-, and dichlorodihydrofluorescein-dependent luminescence. GO-PEG decreased luminescent signal probably due to inactivation of ROS, such as hydroxyl and superoxide radicals. Some types of GO-PEG stimulated secretion of IL-10 by monocytes, but this effect did not correlate with their size or PEG structure.

scholarly journals Synthesis and Characterization of Sulfur and Sulfur-Selenium Nanoparticles Loaded on Reduced Graphene Oxide and Their Antibacterial Activity against Gram-Positive Pathogens

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 191
Author(s):  
Rashmi Niranjan ◽  
Saad Zafar ◽  
Bimlesh Lochab ◽  
Richa Priyadarshini
Keyword(s):  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Spherical Shape ◽  
Dependent Manner ◽  
Gram Positive ◽  
Concentration Dependent Manner ◽  
Reduced Graphene

Resistance to antimicrobial agents in Gram-positive bacteria has become a major concern in the last decade. Recently, nanoparticles (NP) have emerged as a potential solution to antibiotic resistance. We synthesized three reduced graphene oxide (rGO) nanoparticles, namely rGO, rGO-S, and rGO-S/Se, and characterized them using X-ray diffraction (PXRD), Raman analysis, and thermogravimetric analysis. Transmission electron microscopy confirmed spherical shape nanometer size S and S/Se NPs on the rGO surface. Antibacterial properties of all three nanomaterials were probed against Gram-positive pathogens Staphylococcus aureus and Enterococcus faecalis, using turbidometeric and CFU assays. Among the synthesized nanomaterials, rGO-S/Se exhibited relatively strong antibacterial activity against both Gram-positive microorganism tested in a concentration dependent manner (growth inhibition >90% at 200 μg/mL). Atomic force microscopy of rGO-S/Se treated cells displayed morphological aberrations. Our studies also revealed that rGO composite NPs are able to deposit on the bacterial cell surface, resulting in membrane perturbation and oxidative stress. Taken together, our results suggest a possible three-pronged approach of bacterial cytotoxicity by these graphene-based materials.

Effects of Graphene Oxide on Germination and Early Growth of Plants

2021 ◽  
Vol 21 (10) ◽  
pp. 5282-5288
Author(s):  
Ji-Yeon Lee ◽  
Min-Ji Kim ◽  
Haegeun Chung
Keyword(s):  
Graphene Oxide ◽  
Germination Rate ◽  
Thermal Characteristics ◽  
Terrestrial Ecosystems ◽  
Early Growth ◽  
High Concentrations ◽  
Species Specific ◽  
The Impact ◽  
Germination And Growth ◽  
Proper Disposal

Owing to its excellent material properties such as large surface area and superb mechanical and thermal characteristics, graphene oxide (GO) is likely to be applied in a variety of environmental fields. These applications may lead to the entrance of GO in terrestrial ecosystems, but there is little research regarding the impact of GO on plants upon such entrances. To analyze the effects of GO on the germination and growth of various plants, the changes in lettuce, radish, perennial ryegrass, alfalfa, and cucumber seeds under GO treatment was studied. Germination rate and growth were analyzed after the seeds were exposed to GO at 0, 0.2, 0.4, 0.8, and 1.6 mg ml−1. For lettuce, the germination rate decreased with GO concentration. However, no significant effects were observed on the germination rate of other plants. On the other hand, the growth of lettuce, alfalfa, and radish decreased under GO treatment. For example, at 1.6 mg ml−1 of GO, the length of shoot and root of lettuce was shortened by 87% and 86%, respectively. Such results indicate that the germination and early growth of plants can be negatively affected in a species-specific manner under high concentrations of GO. Hence, we anticipate that our results may assist in supplementing the legal regulations for the proper disposal of nanomaterials.

scholarly journals Potentiating Effect of Mandelate and Lactate on Chemically Induced Germination in Members of Bacillus cereus Sensu Lato

2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Alistair H. Bishop
Keyword(s):  
Bacillus Cereus ◽  
Large Scale ◽  
Germination Rate ◽  
Dependent Manner ◽  
Clostridium Sporogenes ◽  
Specific Chemical ◽  
Content Type ◽  
Ph Range ◽  
Significant Discovery ◽  
The Impact

ABSTRACT Endospores of the genus Bacillus can be triggered to germinate by a limited number of chemicals. Mandelate had powerful additive effects on the levels and rates of germination produced in non-heat-shocked spores of Bacillus anthracis strain Sterne, Bacillus cereus, and Bacillus thuringiensis when combined with l-alanine and inosine. Mandelate had no germinant effect on its own but was active with these germinants in a dose-dependent manner at concentrations higher than 0.5 mM. The maximum rate and extent of germination were produced in B. anthracis by 100 mM l-alanine with 10 mM inosine; this was equaled by just 25% of these germinants when supplemented with 10 mM mandelate. Half the maximal germination rate was produced by 40% of the optimum germinant concentrations or 15% of them when supplemented with 0.8 mM mandelate. Germination rates in B. thuringiensis were highest around neutrality, but the potentiating effect of mandelate was maintained over a wider pH range than was germination with l-alanine and inosine alone. For all species, lactate also promoted germination in the presence of l-alanine and inosine; this was further increased by mandelate. Ammonium ions also enhanced l-alanine- and inosine-induced germination but only when mandelate was present. In spite of the structural similarities, mandelate did not compete with phenylalanine as a germinant. Mandelate appeared to bind to spores while enhancing germination. There was no effect when mandelate was used in conjunction with nonnutrient germinants. No effect was produced with spores of Bacillus subtilis, Clostridium sporogenes, or C. difficile. IMPORTANCE The number of chemicals that can induce germination in the species related to Bacillus cereus has been defined for many years, and they conform to specific chemical types. Although not a germinant itself, mandelate has a structure that is different from these germination-active compounds, and its addition to this list represents a significant discovery in the fundamental biology of spore germination. This novel activity may also have important applied relevance given the impact of spores of B. cereus in foodborne disease and B. anthracis as a threat agent. The destruction of spores of B. anthracis, for example, particularly over large outdoor areas, poses significant scientific and logistical problems. The addition of mandelate and lactate to the established mixtures of l-alanine and inosine would decrease the amount of the established germinants required and increase the speed and level of germination achieved. The large-scale application of “germinate to decontaminate” strategy may thus become more practicable.

ENHANCING SEED GERMINATION OF FOUR CROP SPECIES USING AN ULTRASONIC TECHNIQUE

2010 ◽  
Vol 46 (2) ◽  
pp. 231-242 ◽  
Author(s):  
S. J. GOUSSOUS ◽  
N. H. SAMARAH ◽  
A. M. ALQUDAH ◽  
M. O. OTHMAN
Keyword(s):  
Seed Germination ◽  
Treatment Duration ◽  
Germination Rate ◽  
Germination Percentage ◽  
Crop Species ◽  
Maximum Increase ◽  
Beneficial Effects ◽  
The Us ◽  
Two Factors ◽  
Parallel Tests

SUMMARYA laboratory experiment was conducted to determine the effect of ultrasound (US) treatment on seed germination of chickpea, wheat, pepper and watermelon. All tests were carried out at 40 kHz in a water bath ultrasonic device varying two factors, treatment duration (5, 10, 15, 30, 45 or 60 min) and germination temperature (15 or 20 °C). Parallel tests were run in which seeds were soaked in water without sonication in order to eliminate the effect of water from US test results. The effects of US on seed germination varied between crops and were more obvious on germination speed, expressed as germination rate index (GRI), rather than on germination percentage (GP). In particular, US treatment significantly increased the GRI of chickpeas, wheat and watermelon, resulting in a maximum increase of 133% (at 45 min), 95% (30 min) and 45% (5 min), respectively, above control seeds. The beneficial effects of US on the GRI of these crops were observed at both 15 and 20 °C, suggesting that US treatment offers a practical priming method to overcome the slow germination that may occur at low temperatures. Water-soaking treatment improved the GP of both chickpea and pepper seeds by 59 and 24%, respectively, compared to the control but neither water nor US had any positive effect on pepper GRI. Post-treatment measurement of moisture content of these seeds produced variable results depending on crop species and US treatment duration. Results of this research indicated that US treatment effectively enhanced speed of germination of chickpea, wheat and watermelon seeds. This increase in speed of germination may improve early field establishment of these crops in the semiarid Mediterranean region and thus needs further investigation. The US technique may also be very useful for plant propagators in nurseries to achieve fast seedling establishment of watermelon.

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