scholarly journals Antimicrobial Activity of Compounds Containing Silver Nanoparticles and Calcium Glycerophosphate in Combination with Tyrosol

2019 ◽  
Vol 59 (2) ◽  
pp. 147-153 ◽  
Author(s):  
José Antonio Santos Souza ◽  
Debora Barros Barbosa ◽  
Jackeline Gallo do Amaral ◽  
Douglas Roberto Monteiro ◽  
Luiz Fernando Gorup ◽  
...  
Author(s):  
M. Linga Rao ◽  
Bhumi G ◽  
Savithramma N

Silver nanoparticles (SNPs) exhibit tremendous applications in medicine as antimicrobial agent.  The use of different parts of plants for the synthesis of nanoparticles is considered as a green technology as it does not involve any harmful chemicals.  In the present study, we report a rapid biosynthesis of silver nanoparticles from aqueous leaf extract of medicinal plant Allamanda cathartica.  The active phytochemicals present in the plant were responsible for the quick reduction of silver ion to metallic silver nanoparticles. The reduced silver nanoparticles were characterized by using UV-Vis spectrophotometry, Scanning Electron Microscope (SEM), Energy Dispersive Analysis of X-ray (EDAX) and Atomic Force Microscopy (AFM).  The spherical shaped silver nanoparticles were observed and it was found to 19-40 nm range of size.  These phytosynthesized SNPs were tested for their antimicrobial activity and it analyzed by measuring the inhibitory zone. A. cathartica aqueous leaf extract of SNPs showed highest toxicity to Pseudomonas followed by Klebsiella, Bacillus and E. coli and lowest toxicity towards Proteus. In fungal species, highest inhibition zone was noted against Rhizopus followed by Curvularia, Aspergillus flavus and Aspergillus niger and minimum inhibition zone was observed against Fusarium species.  These results suggest a promising potential of Indian plant-based green chemistry for production of SNPs for biomedical and nanotechnology applications.


Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles. 


Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  

Microorganisms like fungi, actinomycetes and bacteria are considered nanofactories and are helpful in the production of nanoparticles useful in the welfare of human beings. In the present study, we investigated the production of silver nanoparticles from Streptomyces species JF714876. Extracellular synthesis of silver nanoparticles by Streptomyces species was carried out using two different media. Silver nanoparticles were examined using UV-visible, IR and atomic force microscopy. The size of silver nanoparticles was in the range of 80-100 nm. Antimicrobial activity of silver nanoparticle against bacteria such as E. coli, S. aureus, and dermatophytes like T. rubrum and T. tonsurans was determined. Thus, this study suggests that the Streptomyces sp. JF741876 can produce silver ions that can be used as an antimicrobial substance.


2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.


2021 ◽  
Vol 9 (6) ◽  
pp. 678
Author(s):  
Kaliyamoorthy Kalidasan ◽  
Nabikhan Asmathunisha ◽  
Venugopal Gomathi ◽  
Laurent Dufossé ◽  
Kandasamy Kathiresan

This work deals with the identification of a predominant thraustochytrid strain, the optimization of culture conditions, the synthesis of nanoparticles, and the evaluation of antioxidant and antimicrobial activities in biomass extracts and nanoparticles. Thraustochytrium kinnei was identified as a predominant strain from decomposing mangrove leaves, and its culture conditions were optimized for maximum biomass production of 13.53 g·L−1, with total lipids of 41.33% and DHA of 39.16% of total fatty acids. Furthermore, the strain was shown to synthesize gold and silver nanoparticles in the size ranges of 10–85 nm and 5–90 nm, respectively. Silver nanoparticles exhibited higher total antioxidant and DPPH activities than gold nanoparticles and methanol extract of the strain. The silver nanoparticles showed higher antimicrobial activity than gold nanoparticles and petroleum ether extract of the strain. Thus, Thraustochytrium kinnei is proven to be promising for synthesis of silver nanoparticles with high antioxidant and antimicrobial activity.


Author(s):  
Meghashyama Bhat ◽  
Bidhayak Chakraborty ◽  
Raju Suresh Kumar ◽  
Abdulrahman I. Almansour ◽  
Natarajan Arumugam ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 97
Author(s):  
Suresh V. Chinni ◽  
Subash C. B. Gopinath ◽  
Periasamy Anbu ◽  
Neeraj Kumar Fuloria ◽  
Shivkanya Fuloria ◽  
...  

The present study was planned to characterize and analyze the antimicrobial activity of silver nanoparticles (AgNP) biosynthesized using a Coccinia indica leaf (CIL) ethanolic extract. The present study included the preparation of CIL ethanolic extract using the maceration process, which was further used for AgNP biosynthesis by silver nitrate reduction. Biosynthetic AgNPs were characterized using UV–Visible spectrometry, zeta potential analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) spectrometry. The biogenic AgNP and CIL extracts were further investigated against different bacterial strains for their antimicrobial activity. The surface plasmon resonance (SPR) signal at 425 nm confirmed AgNP formation. The SEM and TEM data revealed the spherical shape of biogenic AgNPs and size in the range of 8 to 48 nm. The EDX results verified the presence of Ag. The AgNPs displayed a zeta potential of −55.46 mV, suggesting mild AgNP stability. Compared to Gram-positive bacteria, the biogenic AgNPs demonstrated high antibacterial potential against Gram-negative bacteria. Based on the results, the current study concluded that AgNPs based on CIL extract have strong antibacterial potential, and it established that AgNP biosynthesis using CIL ethanol extract is an effective process.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2475
Author(s):  
Amirah Shafilla Mohamad Kasim ◽  
Arbakariya Bin Ariff ◽  
Rosfarizan Mohamad ◽  
Fadzlie Wong Faizal Wong

Silver nanoparticles (AgNPs) have been found to have extensive biomedical and biological applications. They can be synthesised using chemical and biological methods, and coated by polymer to enhance their stability. Hence, the changes in the physico-chemical characteristics of AgNPs must be scrutinised due to their importance for biological activity. The UV-Visible absorption spectra of polyethylene glycol (PEG) -coated AgNPs displayed a distinctive narrow peak compared to uncoated AgNPs. In addition, High-Resolution Transmission Electron Microscopy analysis revealed that the shapes of all AgNPs, were predominantly spherical, triangular, and rod-shaped. Fourier-Transform Infrared Spectroscopy analysis further confirmed the role of PEG molecules in the reduction and stabilisation of the AgNPs. Moreover, dynamic light scattering analysis also revealed that the polydispersity index values of PEG-coated AgNPs were lower than the uncoated AgNPs, implying a more uniform size distribution. Furthermore, the uncoated and PEG-coated biologically synthesised AgNPs demonstrated antagonisms activities towards tested pathogenic bacteria, whereas no antagonism activity was detected for the chemically synthesised AgNPs. Overall, generalisation on the interrelations of synthesis methods, PEG coating, characteristics, and antimicrobial activity of AgNPs were established in this study.


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