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Synthesis and extracellular accumulation of silver nanoparticles by employing radiation-resistant Deinococcus radiodurans, their characterization, and determination of bioactivity.

Kulkarni RR, Shaiwale NS, Deobagkar DN, Deobagkar DD - Int J Nanomedicine (2015)

Bottom Line: AgNPs were characterized using UV/vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy.The microbially synthesized AgNPs exhibited good antimicrobial activity against both Gram-negative and Gram-positive organisms and anti-biofouling activity.Their ability to inhibit growth and proliferation of cancer cell line was also examined, and it could be seen that AgNPs synthesized using D. radiodurans exhibited excellent anticancer activity.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biology Research Laboratory, Center of Advanced Studies, Department of Zoology, University of Pune, Pune, India.

ABSTRACT
There has been rapid progress in exploring microorganisms for green synthesis of nanoparticles since microbes show extraordinary diversity in terms of species richness and niche localization. Microorganisms are easy to culture using relatively inexpensive and simple nutrients under varied conditions of temperature, pressure, pH, etc. In this work, Deinococcus radiodurans that possesses the ability to withstand extremely high radiation and desiccation stress has been employed for the synthesis of silver nanoparticles (AgNPs). D. radiodurans was able to accumulate AgNPs in medium under various conditions, and process optimization was carried out with respect to time, temperature, pH, and concentration of silver salt. AgNPs were characterized using UV/vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The microbially synthesized AgNPs exhibited good antimicrobial activity against both Gram-negative and Gram-positive organisms and anti-biofouling activity. Their ability to inhibit growth and proliferation of cancer cell line was also examined, and it could be seen that AgNPs synthesized using D. radiodurans exhibited excellent anticancer activity.

No MeSH data available.


Related in: MedlinePlus

Transmission electron microscopic images of AgNPs.Notes: AgNPs synthesized using different concentrations of AgNO3: (A) 2.5 mM, (B) 5 mM, and (C) 10 mM. Insert bar corresponds to 50 nm.Abbreviation: AgNPs, silver nanoparticles.
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f3-ijn-10-963: Transmission electron microscopic images of AgNPs.Notes: AgNPs synthesized using different concentrations of AgNO3: (A) 2.5 mM, (B) 5 mM, and (C) 10 mM. Insert bar corresponds to 50 nm.Abbreviation: AgNPs, silver nanoparticles.

Mentions: Microscopic techniques such as SEM and TEM were utilized to characterize the morphology of nanoparticles. The SEM analysis showed that the synthesized AgNPs were spherical in shape (Figure 2A). To obtain better resolution, the AgNPs were scanned using TEM (Figure 2B). From the TEM image, it is evident that the entire surface of the grid was evenly spread, and the AgNPs were well dispersed. The particle size histogram revealed that the average particle size of the AgNPs was 16.82 nm as represented in Figure 2C. The size of nanoparticles ranges from 4 nm to 50 nm with maximum percentage of particles of 15–20 nm and some particles of 5–8 nm sizes, while a very small percentage with diameters ranging from 45 nm to 50 nm could be visualized (data not shown). These variations in shape and size of nanoparticles synthesized by biological systems are common.31 TEM images for other preparation conditions using different concentrations of AgNO3, 5 mM and 10 mM, were also obtained. The average size observed for 2.5 mM was 17 nm (Figure 3A), which was consistent with previous data. The concentration of 5 mM exhibited an average size of 14.41 nm (Figure 3B), while 10 mM showed an average size of 13.45 nm (Figure 3C). There was no significant difference observed in size of AgNPs synthesized using 2.5 mM AgNO3 salt and other concentrations used (5 mM and 10 mM AgNO3 salt). Earlier reports have shown that AgNPs synthesized using various microbes like Pseudomonas stutzeri AG259, Bacillus megaterium, K. pneumoniae, and Bacillus licheniformis exhibit a larger particle size of 200 nm, 80–98.56 nm, 28.2–122 nm, and 50 nm, respectively;32–35 however, biologically synthesized AgNPs using D. radiodurans are comparatively of smaller size (16.82 nm). Nanoparticles with smaller size can have promising applications in biomedicine due to the advantage of increased surface area.


Synthesis and extracellular accumulation of silver nanoparticles by employing radiation-resistant Deinococcus radiodurans, their characterization, and determination of bioactivity.

Kulkarni RR, Shaiwale NS, Deobagkar DN, Deobagkar DD - Int J Nanomedicine (2015)

Transmission electron microscopic images of AgNPs.Notes: AgNPs synthesized using different concentrations of AgNO3: (A) 2.5 mM, (B) 5 mM, and (C) 10 mM. Insert bar corresponds to 50 nm.Abbreviation: AgNPs, silver nanoparticles.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4321572&req=5

f3-ijn-10-963: Transmission electron microscopic images of AgNPs.Notes: AgNPs synthesized using different concentrations of AgNO3: (A) 2.5 mM, (B) 5 mM, and (C) 10 mM. Insert bar corresponds to 50 nm.Abbreviation: AgNPs, silver nanoparticles.
Mentions: Microscopic techniques such as SEM and TEM were utilized to characterize the morphology of nanoparticles. The SEM analysis showed that the synthesized AgNPs were spherical in shape (Figure 2A). To obtain better resolution, the AgNPs were scanned using TEM (Figure 2B). From the TEM image, it is evident that the entire surface of the grid was evenly spread, and the AgNPs were well dispersed. The particle size histogram revealed that the average particle size of the AgNPs was 16.82 nm as represented in Figure 2C. The size of nanoparticles ranges from 4 nm to 50 nm with maximum percentage of particles of 15–20 nm and some particles of 5–8 nm sizes, while a very small percentage with diameters ranging from 45 nm to 50 nm could be visualized (data not shown). These variations in shape and size of nanoparticles synthesized by biological systems are common.31 TEM images for other preparation conditions using different concentrations of AgNO3, 5 mM and 10 mM, were also obtained. The average size observed for 2.5 mM was 17 nm (Figure 3A), which was consistent with previous data. The concentration of 5 mM exhibited an average size of 14.41 nm (Figure 3B), while 10 mM showed an average size of 13.45 nm (Figure 3C). There was no significant difference observed in size of AgNPs synthesized using 2.5 mM AgNO3 salt and other concentrations used (5 mM and 10 mM AgNO3 salt). Earlier reports have shown that AgNPs synthesized using various microbes like Pseudomonas stutzeri AG259, Bacillus megaterium, K. pneumoniae, and Bacillus licheniformis exhibit a larger particle size of 200 nm, 80–98.56 nm, 28.2–122 nm, and 50 nm, respectively;32–35 however, biologically synthesized AgNPs using D. radiodurans are comparatively of smaller size (16.82 nm). Nanoparticles with smaller size can have promising applications in biomedicine due to the advantage of increased surface area.

Bottom Line: AgNPs were characterized using UV/vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy.The microbially synthesized AgNPs exhibited good antimicrobial activity against both Gram-negative and Gram-positive organisms and anti-biofouling activity.Their ability to inhibit growth and proliferation of cancer cell line was also examined, and it could be seen that AgNPs synthesized using D. radiodurans exhibited excellent anticancer activity.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biology Research Laboratory, Center of Advanced Studies, Department of Zoology, University of Pune, Pune, India.

ABSTRACT
There has been rapid progress in exploring microorganisms for green synthesis of nanoparticles since microbes show extraordinary diversity in terms of species richness and niche localization. Microorganisms are easy to culture using relatively inexpensive and simple nutrients under varied conditions of temperature, pressure, pH, etc. In this work, Deinococcus radiodurans that possesses the ability to withstand extremely high radiation and desiccation stress has been employed for the synthesis of silver nanoparticles (AgNPs). D. radiodurans was able to accumulate AgNPs in medium under various conditions, and process optimization was carried out with respect to time, temperature, pH, and concentration of silver salt. AgNPs were characterized using UV/vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The microbially synthesized AgNPs exhibited good antimicrobial activity against both Gram-negative and Gram-positive organisms and anti-biofouling activity. Their ability to inhibit growth and proliferation of cancer cell line was also examined, and it could be seen that AgNPs synthesized using D. radiodurans exhibited excellent anticancer activity.

No MeSH data available.


Related in: MedlinePlus