Extracellular synthesis of silver nanoparticles by bioluminescent bacteria: characterization and evaluation of its antibacterial and antioxidant properties

Author(s):  
Rajendran Srinivasan ◽  
Krishnamurthy Mathivanan ◽  
Rasiravathanahalli Kaveriyappan Govindarajan ◽  
Jayaraman Uthaya Chandirika ◽  
Chinnavenkataraman Govindasamy
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 10 (2) ◽  
pp. 2096-2106

Pleurotus florida of the genus Pleurotus is a delicious edible mushroom with high therapeutic potential. Silver nanoparticles (AgNPs) are gaining a lot of importance nowadays because of their wide industrial and biomedical applications. Capping of AgNPs with polysaccharides, the most potent mushroom derived metabolites, is promising towards natural drug development for free radical-induced ailments. In the present investigation, silver nanoparticles were synthesized using β-glucan isolated from P. florida, and their antioxidant properties were studied. Polysaccharide (PS) isolation was carried out by hot water extraction, alcohol precipitation, deproteinization, and dialysis. Preliminary characterization of PS by Anthrone, Lowry’s method, Paper Chromatography, and FT-IR showed that PS is protein-bound β-(1-3) - Glucan. Synthesis of Silver nanoparticle from PS (PS-AgNPs) was confirmed by UV spectroscopy. Antioxidant properties of PS and PS-AgNPs were evaluated by Total antioxidant capacity assay, DPPH assay, Total reducing power, and Hydroxyl radical scavenging assay. Both PS and PS-AgNPs showed profound antioxidant activity in a dose-dependent manner, and PS-AgNPs was more active than PS. The highest activity was shown in Hydroxyl radical scavenging assay in which PS and PS-AgNPs showed 81.8% and 89.4% activity, respectively, at the highest tested dose. The present study revealed the possible use of P. florida in antioxidant drug development.


2019 ◽  
Vol 13 (3) ◽  
pp. 223-231
Author(s):  
Zahra Goli ◽  
Cobra Izanloo

Background: Silver nanoparticles have a profound role in the field of high sensitivity biomolecular detection, catalysis, biosensors and medicine. In the present study, aqueous extract of Dracocephalum kotschyi has been used for the synthesis of silver nanoparticles. Objective: In this study, we evaluated the antioxidant features and the possibility of biosynthesis of AgNPs using an aqueous extract of Dracocephalum kotschyi and also evaluated the antibacterial activities of the synthesized nanoparticles. Methods: An eco-friendly and cost-effective protocol for the synthesis of Ag nanoparticles by utilizing a renewable natural resource, aqueous solution of Dracocephalum kotschyi, was proposed. Synthesized nanoparticles were characterized by UV–Vis spectroscopy, SEM, EDS, and XRD pattern. Results: At first, the extract of Dracocephalum kotschyi was assessed to determine and confirm the presence of an antioxidant feature. Resuscitation of one mM silver nitrate solution was carried out by the herbal extract. The solution containing AgNPs obtained from green synthesis had a maximum optical density at 225 nm. In addition, the presence of AgNPs was approved by energy-dispersive X-ray spectroscopy (EDS). Images of the scanning electron microscope demonstrated that the synthesized AgNPs had the shape of rods and the size distribution of 48-51 nm. One of the benefits of this method is a uniform size distribution. Moreover, the effects of reaction time and concentration of the herbal extract were assessed by ultraviolet-visible (UV-Vis) spectroscopy. In the end, we assessed the antibacterial impact of the synthesized AgNPs against some pathogenic bacterial strains. According to the results, the produced nanostructures had a proper impact on two bacteria of Escherichia coli and Staphylococcus aureus. Conclusion: According to the results of the present study, Dracocephalum kotschyi can be a suitable compound for the synthesis of nanostructures due to its indigenous cultivation and great medicinal properties.


2002 ◽  
Vol 14 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Meenal Kowshik ◽  
Shriwas Ashtaputre ◽  
Sharmin Kharrazi ◽  
W Vogel ◽  
J Urban ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document