Determination of the mechanism of photoinduced toxicity of selected metal oxide nanoparticles (ZnO, CuO, Co3O4 and TiO2) to E. coli bacteria

2013 ◽  
Vol 25 (5) ◽  
pp. 882-888 ◽  
Author(s):  
Thabitha P. Dasari ◽  
Kavitha Pathakoti ◽  
Huey-Min Hwang
Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2505
Author(s):  
Amal M. Al-Mohaimeed ◽  
Wedad A. Al-Onazi ◽  
Maha F. El-Tohamy

The current work described the synthesis and characterization of zinc oxide nanoparticles (ZnONPs) and their electrocatalytic activity in the determination of minocycline hydrochloride (MCL). The unique features of metal oxide nanoparticles such as zinc oxide encourage the researchers to investigate the activity of metal oxide nanoparticles as remarkable semiconductor materials active in the electrochemical sensing determination. Herein, the suggested study displayed a comparative determination of minocycline hydrochloride using two conventional and modified ZnONPs-coated wire sensors. The recorded results showed the linear behavior of the enriched ZnONPs sensor over the 1.0 × 10−10–1.0 × 10−2 mol L−1 with respect to 1.0 × 10−6–1.0 × 10−2 mol L−1 for the conventional sensor. The two sensors are working in the pH range of 3–5 with regression equations EmV = (53.2 ± 0.5) log [MCL] + 448.8 and EmV = (58.7 ± 0.2) log [MCL] + 617.76 for conventional and enriched ZnONPs, respectively. The correlation coefficients were 0.9995 and 0.9998 for the previously mentioned sensors, respectively. The validity of the suggested analytical method was evaluated according to the recommended guidelines for methodology and drug analysis. The developed sensors were also used in the quantification of MCL in commercial formulations.


Author(s):  
Mahbooubeh Mirhosseini ◽  
Roghayeh Dehestani

Background: The spread of pathogenic microorganisms in food and beverage and their resistance to antibiotics have raised major concerns for public health. The aim of this study was to investigate the antimicrobial activity of various metal oxide nanoparticles (NPs) including zinc oxide (ZnO), magnesium oxide (MgO), and iron oxide (Fe2O3) NPs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, the antimicrobial activity of these NPs in milk was studied along with mild heat. Methods: In this experimental study, the antibacterial activity of ZnO, MgO, and Fe2O3 NPs were initially evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Later, the antimicrobial effect of these NPs was investigated in milk along with mild heating. To determine the morphological changes in S. aureus and E. coli, electron microscopy scanning was applied before and after the antimicrobial treatments. Results: The MBC and MIC values presented by Fe2O3, ZnO, and MgO NPs against pathogenic bacteria showed that MgO NPs were the most potent substances for inhibiting the growth of S. aureus and E. coli. The results also indicated that use of these NPs had synergistic effects in combination with the heating treatment. Electron microscopy scanning also revealed that treatment with MgO NPs could distort and impair the cell wall of the pathogenic bacteria, leading to the leakage of intracellular components and bacterial death. Conclusion: The results suggest that MgO, ZnO, and Fe2O3 NPs can be applied for industrial food processing as effective antimicrobial compounds to decrease the temperature required for pasteurizing milk.


2020 ◽  
Vol 20 (3) ◽  
pp. 1440-1446
Author(s):  
In Chul Kong ◽  
Xin Yang ◽  
Wonil Wi ◽  
Minji Kim ◽  
Kyung-Seok Ko

The effects of six metal oxide nanoparticles (MO-NPs) on the activity and biosynthesis of an enzyme (β-galactosidase) were examined using a mutant strain of E. coli. Different sensitivities were observed according to the type of NP and metabolic process. The toxic effects on enzyme activity were significantly greater than on biosynthesis (p < 0.011), except in the presence of NiO. In both cases, ZnO NP caused the greatest inhibition among the tested NPs, followed by CuO. The EC50s for ZnO were 0.19 and 3.68 mg/L for enzyme activity and biosynthesis, respectively. Similar orders of toxicity were observed as follows: ZnO > CuO > NiO > Co3O4 > TiO2, Al2O3 for enzyme activity; and ZnO > CuO > NiO ≫ Al2O3, TiO2, Co3O4 for the biosynthetic process. More systematic research, including in-depth studies like investigation of the molecular mechanisms, is necessary to elucidate the detailed mechanisms of inhibition involved in both metabolic processes.


Author(s):  
Victor E Kuz'min ◽  
Liudmila N Ognichenko ◽  
Natalia Sizochenko ◽  
Valery A. Chapkin ◽  
Sergii I. Stelmakh ◽  
...  

A poor applicability of classic 2D descriptors for representation of metal oxide nanoparticles is briefly discussed. The combination of 1D descriptors with previously calculated size-dependent descriptors is utilized to represent the structural features of nanoparticles in QSAR modeling. For this purpose, descriptors based on the fundamental characteristics of atoms (nuclear charge, oxidation level, electronegativity, ionic radius, ionic refraction etc.) were combined with those derived from structural formula (doublets –A2, AB, …; triplets – A3, A2B, ABC, … etc.) and “liquid drop model” derived size-dependent parameters. Nano-QSAR models are developed for cytotoxicity of metal oxide nanoparticles against E. coli and HaCaT cells. Two developed nano-QSAR models are discussed in terms of cluster analysis.


Author(s):  
Victor E Kuz'min ◽  
Liudmila N Ognichenko ◽  
Natalia Sizochenko ◽  
Valery A. Chapkin ◽  
Sergii I. Stelmakh ◽  
...  

A poor applicability of classic 2D descriptors for representation of metal oxide nanoparticles is briefly discussed. The combination of 1D descriptors with previously calculated size-dependent descriptors is utilized to represent the structural features of nanoparticles in QSAR modeling. For this purpose, descriptors based on the fundamental characteristics of atoms (nuclear charge, oxidation level, electronegativity, ionic radius, ionic refraction etc.) were combined with those derived from structural formula (doublets –A2, AB, …; triplets – A3, A2B, ABC, … etc.) and “liquid drop model” derived size-dependent parameters. Nano-QSAR models are developed for cytotoxicity of metal oxide nanoparticles against E. coli and HaCaT cells. Two developed nano-QSAR models are discussed in terms of cluster analysis.


Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 742
Author(s):  
Georgy D. Otinov ◽  
Alina V. Lokteva ◽  
Anastasia D. Petrova ◽  
Irina V. Zinchenko ◽  
Maria V. Isaeva ◽  
...  

Rapid development of antibiotic resistance in bacteria is a critical public health problem in the world. One of the main routes of resistance development is the transfer of genes containing antibiotic resistance cassettes. Gene transfer can be done through horizontal transfer of genes: transduction, conjugation, and transformation. Many factors in the environment influence these processes, and one of them is the action of metal oxide nanoparticles (MONPs), which can appear in the milieu through both biological synthesis and the release of engineered nanomaterial. In this study, the effect of AlOOH, CuO, Fe3O4, TiO2, and ZnO MONPs on the transformation (heat shock transformation) of bacteria Escherichia coli K12, and the conjugation between E. coli cc118 and E. coli Nova Blue were studied. The MONPs were synthesized by one method and fully characterized. ZnO nanoparticles (NPs) have significantly increased the efficiency of transformation (more than 9-fold), while the other NPs have reduced it to 31 times (TiO2 NPs). AlOOH NPs increased the number of transconjugants more than 1.5-fold, while CuO and Fe3O4 NPs did not have a significant effect on transformation and conjugation. Thus, the data shows that different types of MONPs can enhance or inhibit different gene transfer mechanisms, affecting the spread of antibiotic resistance genes.


2017 ◽  
Vol 95 (8) ◽  
pp. 863-866 ◽  
Author(s):  
Zhengwei Zhou ◽  
Xinwen Tang ◽  
Wen Dai ◽  
Jingjie Shi ◽  
Haiqun Chen

Nanotechnology has been applied to many aspects of human life. Meanwhile, concerns regarding the toxicity of engineered nanomaterials to the environment have also been growing. Herein, an economic and convenient approach based on quantitative structure–activity relationship for nanomaterials (nano-QSAR) was proposed to evaluate the cytotoxicity of metal oxide nanoparticles (MONPs) to E. coli. Six molecular descriptors of 17 MONPs were selected and calculated using Gaussian98 software and DFT-B3LYP method on the LANL2DZ basis set. Two multivariable models, linear and nonlinear, were built based on the calculated molecular descriptors using multiple linear regression (MLR) and support vector machine (SVM) methods, respectively. Results demonstrated that both models presented high reliability, good predictive performance, and fine generalization ability, with all R2 values greater than 0.84. It was also revealed that the lowest unoccupied molecular orbital (LUMO) and molar heat capacity (Cp) were the two key descriptors influencing the cytotoxicity of MONPs.


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