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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

Antibacterial and Anti-biofouling activity of silver nanoparticles.Notes: (A) Representative results of antimicrobial activity of nanoparticles against Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa. (B) Anti-biofouling activity of silver nanoparticles against Gram-negative P. aeruginosa and Gram-positive S. aureus. The figure depicts a graph showing percent viability of the P. aeruginosa (statistically significant P=1.72×10−6 [ANOVA] and P<0.01 [t-test]) and S. aureus (P=4.64×10−11 [ANOVA] and P<0.0001 [t-test]) against the varying concentrations of silver nanoparticles.Abbreviation: ANOVA, analysis of variance.
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f5-ijn-10-963: Antibacterial and Anti-biofouling activity of silver nanoparticles.Notes: (A) Representative results of antimicrobial activity of nanoparticles against Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa. (B) Anti-biofouling activity of silver nanoparticles against Gram-negative P. aeruginosa and Gram-positive S. aureus. The figure depicts a graph showing percent viability of the P. aeruginosa (statistically significant P=1.72×10−6 [ANOVA] and P<0.01 [t-test]) and S. aureus (P=4.64×10−11 [ANOVA] and P<0.0001 [t-test]) against the varying concentrations of silver nanoparticles.Abbreviation: ANOVA, analysis of variance.

Mentions: Several studies have demonstrated that biosynthesized AgNPs alone or in combination with antibiotics tend to have strong bactericidal activity against Gram-negative and Gram-positive bacteria38 including multidrug-resistant strains such as E. coli, P. aeruginosa, and S. aureus.39 In this study, the antibacterial activity of the synthesized AgNPs was investigated using the agar well diffusion method and standard dilution micromethod. The results for the inhibition zones and their average values obtained from agar well diffusion assay are shown in Figure 5A. In liquid growth experiments, 91% growth inhibition was observed when E. coli (106 CFU/mL) was treated with 150 μg/mL concentration of AgNPs for 3 hours, and a decline in CFU per milliliter was seen from 1.54×107 (untreated control) to 1.42×106 (AgNPs treated), while in the case of Gram-positive S. aureus (106 CFU/mL), treatment with 150 μg/mL of AgNPs for 3 hours exhibited a 46% growth inhibition with CFU per milliliter reducing from 8.6×107 (untreated control) to 4.64×107 (AgNPs treated). Therefore, it was apparent that all bacterial cultures used in this study were inhibited by AgNPs. Gram-negative bacteria were highly suppressed by the AgNPs compared to Gram-positive bacteria. Among the Gram-negative bacteria, P. vulgaris was inhibited the most followed by E. coli and P. aeruginosa, while among the Gram-positive bacteria, S. aureus was more susceptible followed by B. subtilis. Antibacterial activity of AgNPs (160–200 μg/mL) against B. subtilis, Bacillus cereus, E. coli, and P. aeruginosa has been reported.40–42 AgNPs synthesized using D. radiodurans exhibited an effective antibacterial activity at a concentration of 150 μg/mL. Antibiotic resistance is the biggest challenge to the medical field for the treatment of infectious diseases, particularly due to the emergence of multidrug-resistant pathogenic strains. Thus, AgNPs synthesized in the present study could offer a potential as an effective antibacterial agent alone or in combination for the management of antibiotic-resistant bacterial diseases after completing the successful clinical trials. In earlier reports on antibacterial activity of AgNPs, it has been observed that maximum inhibition of AgNPs was against Gram-negative microorganisms as compared to Gram-positive microorganisms,43 which may be probably associated with the differences in their cell wall composition.39,44 However, the exact mechanism by which the AgNPs exert their antibacterial effect remains to be elucidated.


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)

Antibacterial and Anti-biofouling activity of silver nanoparticles.Notes: (A) Representative results of antimicrobial activity of nanoparticles against Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa. (B) Anti-biofouling activity of silver nanoparticles against Gram-negative P. aeruginosa and Gram-positive S. aureus. The figure depicts a graph showing percent viability of the P. aeruginosa (statistically significant P=1.72×10−6 [ANOVA] and P<0.01 [t-test]) and S. aureus (P=4.64×10−11 [ANOVA] and P<0.0001 [t-test]) against the varying concentrations of silver nanoparticles.Abbreviation: ANOVA, analysis of variance.
© Copyright Policy
Related In: Results  -  Collection

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

f5-ijn-10-963: Antibacterial and Anti-biofouling activity of silver nanoparticles.Notes: (A) Representative results of antimicrobial activity of nanoparticles against Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa. (B) Anti-biofouling activity of silver nanoparticles against Gram-negative P. aeruginosa and Gram-positive S. aureus. The figure depicts a graph showing percent viability of the P. aeruginosa (statistically significant P=1.72×10−6 [ANOVA] and P<0.01 [t-test]) and S. aureus (P=4.64×10−11 [ANOVA] and P<0.0001 [t-test]) against the varying concentrations of silver nanoparticles.Abbreviation: ANOVA, analysis of variance.
Mentions: Several studies have demonstrated that biosynthesized AgNPs alone or in combination with antibiotics tend to have strong bactericidal activity against Gram-negative and Gram-positive bacteria38 including multidrug-resistant strains such as E. coli, P. aeruginosa, and S. aureus.39 In this study, the antibacterial activity of the synthesized AgNPs was investigated using the agar well diffusion method and standard dilution micromethod. The results for the inhibition zones and their average values obtained from agar well diffusion assay are shown in Figure 5A. In liquid growth experiments, 91% growth inhibition was observed when E. coli (106 CFU/mL) was treated with 150 μg/mL concentration of AgNPs for 3 hours, and a decline in CFU per milliliter was seen from 1.54×107 (untreated control) to 1.42×106 (AgNPs treated), while in the case of Gram-positive S. aureus (106 CFU/mL), treatment with 150 μg/mL of AgNPs for 3 hours exhibited a 46% growth inhibition with CFU per milliliter reducing from 8.6×107 (untreated control) to 4.64×107 (AgNPs treated). Therefore, it was apparent that all bacterial cultures used in this study were inhibited by AgNPs. Gram-negative bacteria were highly suppressed by the AgNPs compared to Gram-positive bacteria. Among the Gram-negative bacteria, P. vulgaris was inhibited the most followed by E. coli and P. aeruginosa, while among the Gram-positive bacteria, S. aureus was more susceptible followed by B. subtilis. Antibacterial activity of AgNPs (160–200 μg/mL) against B. subtilis, Bacillus cereus, E. coli, and P. aeruginosa has been reported.40–42 AgNPs synthesized using D. radiodurans exhibited an effective antibacterial activity at a concentration of 150 μg/mL. Antibiotic resistance is the biggest challenge to the medical field for the treatment of infectious diseases, particularly due to the emergence of multidrug-resistant pathogenic strains. Thus, AgNPs synthesized in the present study could offer a potential as an effective antibacterial agent alone or in combination for the management of antibiotic-resistant bacterial diseases after completing the successful clinical trials. In earlier reports on antibacterial activity of AgNPs, it has been observed that maximum inhibition of AgNPs was against Gram-negative microorganisms as compared to Gram-positive microorganisms,43 which may be probably associated with the differences in their cell wall composition.39,44 However, the exact mechanism by which the AgNPs exert their antibacterial effect remains to be elucidated.

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