Biosynthesis of silver nanoparticles from silver(i) reduction by the periplasmic nitrate reductase c-type cytochrome subunit NapC in a silver-resistant E. coli

2014 ◽  
Vol 5 (8) ◽  
pp. 3144-3150 ◽  
Author(s):  
Iris Wing-Shan Lin ◽  
Chun-Nam Lok ◽  
Chi-Ming Che
Keyword(s):  
Silver Nanoparticles ◽  
Nitrate Reductase ◽  
Silver Ions ◽  
E Coli ◽  
Periplasmic Nitrate Reductase

The periplasmic nitrate reductase c-type cytochrome subunit NapC plays a major role in the biosynthesis of silver nanoparticles from the reduction of silver ions in a silver-resistantE. coli.

Antimicrobial Activity of Silver Nanoparticles Synthesized by Streptomyces Species JF714876

2012 ◽  
Vol 5 (1) ◽  
pp. 1638-1642 ◽  
Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Ions ◽  
Human Beings ◽  
Streptomyces Species ◽  
Force Microscopy ◽  
E Coli ◽  
Extracellular Synthesis ◽  
Atomic Force ◽  
Uv Visible

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.

scholarly journals Periplasmic Nitrate Reductase (NapABC Enzyme) Supports Anaerobic Respiration by Escherichia coli K-12

2002 ◽  
Vol 184 (5) ◽  
pp. 1314-1323 ◽  
Author(s):  
Valley Stewart ◽  
Yiran Lu ◽  
Andrew J. Darwin
Keyword(s):  
Escherichia Coli ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Anaerobic Respiration ◽  
Null Alleles ◽  
E Coli ◽  
Periplasmic Nitrate Reductase ◽  
Nitrate Concentrations ◽  
K 12

ABSTRACT Periplasmic nitrate reductase (NapABC enzyme) has been characterized from a variety of proteobacteria, especially Paracoccus pantotrophus. Whole-genome sequencing of Escherichia coli revealed the structural genes napFDAGHBC, which encode NapABC enzyme and associated electron transfer components. E. coli also expresses two membrane-bound proton-translocating nitrate reductases, encoded by the narGHJI and narZYWV operons. We measured reduced viologen-dependent nitrate reductase activity in a series of strains with combinations of nar and nap null alleles. The napF operon-encoded nitrate reductase activity was not sensitive to azide, as shown previously for the P. pantotrophus NapA enzyme. A strain carrying null alleles of narG and narZ grew exponentially on glycerol with nitrate as the respiratory oxidant (anaerobic respiration), whereas a strain also carrying a null allele of napA did not. By contrast, the presence of napA+ had no influence on the more rapid growth of narG+ strains. These results indicate that periplasmic nitrate reductase, like fumarate reductase, can function in anaerobic respiration but does not constitute a site for generating proton motive force. The time course of Φ(napF-lacZ) expression during growth in batch culture displayed a complex pattern in response to the dynamic nitrate/nitrite ratio. Our results are consistent with the observation that Φ(napF-lacZ) is expressed preferentially at relatively low nitrate concentrations in continuous cultures (H. Wang, C.-P. Tseng, and R. P. Gunsalus, J. Bacteriol. 181:5303-5308, 1999). This finding and other considerations support the hypothesis that NapABC enzyme may function in E. coli when low nitrate concentrations limit the bioenergetic efficiency of nitrate respiration via NarGHI enzyme.

Characterization and antibacterial properties of Eriobotrya japonica extract loaded silver-nanoparticles

2020 ◽  
Vol 16 ◽  
Author(s):  
Arfaa Sajid ◽  
Qaisar Manzoor ◽  
Anam Sajid ◽  
Muhammad Imran ◽  
Shanza Khalid ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Silver Ions ◽  
Eriobotrya Japonica ◽  
X Ray Diffraction ◽  
Effective Utilization ◽  
E Coli ◽  
Elongated Nanoparticles

Background:: Currently, developing methods for the formation of nanoparticles with antimicrobial properties based on green chemistry are the research hotspots. In this research green biosynthesis of Eriobotrya japonica extract loaded silver nanoparticles and their characterization were the main objectives to achieve. Methods:: Green synthesis of E. japonica leaves extract-loaded silver nanoparticles (AgNPs) was carried out and its effect on bacterial growth was examined. The reduction of silver ions in solution was observed using UV-Vis spectrophotometer. The properties of AgNPs were assessed using Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Also, their antibacterial effects were checked against Staphylococcus aureus and Escherichia coli. Results:: It was revealed that 5-50 nm sized spherical to elongated nanoparticles were synthesized that possessed comparatively better antibacterial potential against E. coli and S. aureus than conventional extract of the E. japonica leaves. Conclusions:: Green synthesis and effective utilization of Eriobotrya japonica extract loaded silver nanoparticles is a promising approach for nanoparticle production avoiding negative environmental impacts.

scholarly journals Fusarium as a Novel Fungus for the Synthesis of Nanoparticles: Mechanism and Applications

2021 ◽  
Vol 7 (2) ◽  
pp. 139 ◽  
Author(s):  
Mahendra Rai ◽  
Shital Bonde ◽  
Patrycja Golinska ◽  
Joanna Trzcińska-Wencel ◽  
Aniket Gade ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Silver Nanoparticles ◽  
Nitrate Reductase ◽  
Biological System ◽  
Silver Ions ◽  
Cost Effective ◽  
Fusarium Spp ◽  
Synthesis Of Nanoparticles ◽  
Green Approach ◽  
The World

Nanotechnology is a new and developing branch that has revolutionized the world by its applications in various fields including medicine and agriculture. In nanotechnology, nanoparticles play an important role in diagnostics, drug delivery, and therapy. The synthesis of nanoparticles by fungi is a novel, cost-effective and eco-friendly approach. Among fungi, Fusarium spp. play an important role in the synthesis of nanoparticles and can be considered as a nanofactory for the fabrication of nanoparticles. The synthesis of silver nanoparticles (AgNPs) from Fusarium, its mechanism and applications are discussed in this review. The synthesis of nanoparticles from Fusarium is the biogenic and green approach. Fusaria are found to be a versatile biological system with the ability to synthesize nanoparticles extracellularly. Different species of Fusaria have the potential to synthesise nanoparticles. Among these, F. oxysporum has demonstrated a high potential for the synthesis of AgNPs. It is hypothesised that NADH-dependent nitrate reductase enzyme secreted by F. oxysporum is responsible for the reduction of aqueous silver ions into AgNPs. The toxicity of nanoparticles depends upon the shape, size, surface charge, and the concentration used. The nanoparticles synthesised by different species of Fusaria can be used in medicine and agriculture.

scholarly journals The NapF protein of the Escherichia coli periplasmic nitrate reductase system: demonstration of a cytoplasmic location and interaction with the catalytic subunit, NapA

Microbiology ◽  
2006 ◽  
Vol 152 (11) ◽  
pp. 3227-3237 ◽  
Author(s):  
Arjaree Nilavongse ◽  
T. Harma C. Brondijk ◽  
Tim W. Overton ◽  
David J. Richardson ◽  
Emily R. Leach ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nitrate Reductase ◽  
Intact Cell ◽  
Subcellular Location ◽  
Anaerobic Growth ◽  
Cell Fractionation ◽  
Post Translational Modification ◽  
E Coli ◽  
Periplasmic Nitrate Reductase ◽  
And Function

The periplasmic nitrate reductase of Escherichia coli is important during anaerobic growth in low-nitrate environments. The nap operon encoding this nitrate reductase comprises seven genes including a gene, napF, that encodes a putative cytoplasmic iron–sulphur protein of uncertain subcellular location and function. In this study, N-terminal sequence analysis, cell fractionation coupled with immunoblotting and construction of LacZ and PhoA fusion proteins were used together to establish that NapF is located in the E. coli cytoplasm. A bacterial two-hybrid protein–protein interaction system was used to demonstrate that NapF interacted in the cytoplasm with the terminal oxidoreductase NapA, but that it did not self-associate or interact with other electron-transport components of the Nap system, NapC, NapG or NapH, or with another cytoplasmic component, NapD. NapF, purified as a His6-tagged protein, exhibited spectral properties characteristic of an iron–sulphur protein. This protein was able to pull down NapA from soluble extracts of E. coli. A growth-based assay for NapF function in intact cell cultures was developed and applied to assess the effect of mutation of a number of conserved amino acids. It emerged that neither a highly conserved N-terminal double-arginine motif, nor a conserved proline motif, is essential for NapF-dependent growth. The combined data indicate that NapF plays one or more currently unidentified roles in the post-translational modification of NapA prior to the export of folded NapA via the twin-arginine translocation pathway into the periplasm.

scholarly journals EVALUATION OF PHYTOCHEMICAL CONSTITUENTS AND ANTIMICROBIAL ACTIVITY OF SILVER NANOPARTICLE SYNTHESIZED IPOMOEA NIL AGAINST SELECTED PATHOGENS

2017 ◽  
Vol 10 (3) ◽  
pp. 183
Author(s):  
Asha Sivaji ◽  
Asha A ◽  
Rajeshkumar S
Keyword(s):  
Silver Nanoparticles ◽  
Aqueous Extract ◽  
Pathogenic Bacteria ◽  
Color Change ◽  
Silver Ions ◽  
Inhibition Zone ◽  
E Coli ◽  
Ipomoea Nil ◽  
Inhibition Zones ◽  
Phytochemical Constituents

ABSTRACTObjective: The objective of this study is to investigate a simple and feasible approach for the production of silver nanoparticles (AgNPs) by using leafextract of Ipmoea nil and to evaluate its antibacterial activity.Methods: The AgNPs synthesized was characterized by a change in color and the absorption peaks by ultraviolet-visible spectroscopy. The phytocompounds responsible for the reduction and capping of silver ions was known from Fourier transform infrared spectra and phytochemical analysis.The antibacterial effects of prepared aqueous AgNPs were detected against five types of pathogenic bacteria, including Gram-negative and Grampositivebacteria (Escherichia coli, Salmonella, Bacillius, Proteus, and Klebsilla pneumonia) using agar well diffusion method.Results: A peak absorption value between 400 and 450 nm and the color change of the extract from yellowish to red wine were corresponds tothe plasmon absorbance of AgNPs. On the other hand, aqueous extract of I. nil mediated AgNPs found to be effective against tested microorganisms(Salmonella, Bacillus, and Proteus) with inhibition zone in the range of 10-13 mm (20 μl and 10 μl) except E. coli and K. pneumonia. Furthermore,aqueous extract of I. nil leaves had no ability to suppress the growth of the tested microorganisms in the concentration of 10 μl. The control alsoproduced similar inhibition zones like AgNPs.Conclusions: Our findings indicated that green synthesized AgNPs mediated by I. nil leaf extract had an efficient anti-bactericidal activity against thebacterial species tested. Hence, further studies are needed to highlight its mechanism and application as an antibacterial agent.Keywords: Ipomoea nil, Silver nanoparticles, Antibacterial activity, Bacteria.

Green Synthesis of Silver Nanoparticles Using Flos Sophorae immaturus Extract and Bactericidal Activity

2011 ◽  
Vol 317-319 ◽  
pp. 475-478
Author(s):  
Zhi Yun Du ◽  
Zhi Kai Tang ◽  
Rong Qing Mo ◽  
Yu Jing Lu ◽  
Yong Fu Jiang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Chinese Medicine ◽  
Bactericidal Activity ◽  
Room Temperature ◽  
Silver Ions ◽  
Water Soluble ◽  
E Coli ◽  
Zeta Potentials ◽  
Vis Spectroscopy

Silver nanoparticles (AgNPs) were rapidly synthesized by treating silver ions with the extract of a well-known Traditional Chinese Medicine herb, Flos Sophorae Immaturus, at room temperature. The AgNPs were characterized by UV–vis spectroscopy and zeta potentials analysis. The bactericidal activity of the AgNPs against S. aureus and E. coli was investigated. The results indicated that the AgNPs synthesized by Flos Sophorae Immaturus extract were water-soluble nanoparticles with 30-60 nm size, zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative, and the antibacterial activity of the green prepared AgNPs exhibited potent bactericidal activity on S. aureus and E. coli.

Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

2011 ◽  
Vol 4 (3) ◽  
pp. 1491-1496
Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Therapeutic Potential ◽  
Chemical Reduction ◽  
Ultrasonic Field ◽  
Great Promise ◽  
Chemical Reduction Method ◽  
E Coli

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. 

Efficacy of Silver Nanoparticles Synthesized from Hymenocallis species (Spider Lilly) Leaf Extract as Antimicrobial Agents

2019 ◽  
Vol 12 (5) ◽  
pp. 4644-4647
Author(s):  
K.K. Gupta ◽  
Neha Kumari ◽  
Neha Sinha ◽  
Akruti Gupta
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Antimicrobial Agents ◽  
Color Change ◽  
Bacterial Species ◽  
Antimicrobial Property ◽  
Biogenic Synthesis ◽  
E Coli ◽  
Light Yellow ◽  
Antibiotic Property

Biogenic synthesis of silver nanoparticles synthesized from Hymenocallis species (Spider Lilly) leaf extract was subjected for investigation of its antimicrobial property against four bacterial species (E. coli, Salmonella sp., Streptococcus sp. & Staphylococcus sp.). The results revealed that synthesized nanoparticles solution very much justify the color change property from initial light yellow to final reddish brown during the synthesis producing a characteristics absorption peak in the range of 434-466 nm. As antimicrobial agents, their efficacy was evaluated by analysis of variance in between the species and among the different concentration of AgNPs solution, which clearly showed that there was significant variation in the antibiotic property between the four different concentrations of AgNPs solution and also among four different species of bacteria taken under studies. However, silver nanoparticles solution of 1: 9 and 1:4 were proved comparatively more efficient as antimicrobial agents against four species of bacteria.

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