scholarly journals Extracellular Biosynthesis of Silver Nanoparticles Using Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633, and Streptococcus thermophilus ESh1 and Their Antimicrobial Activities

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Abd El-Raheem R. El-Shanshoury ◽  
Sobhy E. ElSilk ◽  
Mohamed E. Ebeid
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Bacillus Subtilis ◽  
Aqueous Media ◽  
Streptococcus Thermophilus ◽  
Antimicrobial Activities ◽  
Silver Ion ◽  
Metallic Silver ◽  
Extracellular Biosynthesis

The development of reliable and eco-friendly organisms of silver nanomaterials is an important aspect of current nanotechnology research and application. Recently, microorganisms have been explored as potential biofactory for synthesis of silver nanoparticles. In this study, through screening of common bacteria, we report extracellular biosynthesis of metallic silver nanoparticles by the reduction of aqueous Ag+ using Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633, and Streptococcus thermophilus ESh1 as potential candidates for the rapid synthesis of silver nanoparticles. The culture supernatant of silver nanoparticles biosynthesis by reduction of silver ion coming in contact with the cell filtrate was fast and was formed within few minutes. UV-visible spectrum of the aqueous media obtained from the above bacteria containing silver ion showed a peak around 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) micrographs showed formation of well-dispersed silver nanoparticles in the range of 5–25 nm. X-ray diffraction (XRD) of silver nanoparticles exhibited 2θ values corresponding to the silver nanocrystal. In vitro studies indicated that the formed silver nanoparticles showed variable antimicrobial activity against Escherichia coli, Bacillus subtilis, Salmonella typhimurium, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa and the fungus like yeast (Candida albicans). The diameter of inhibition zone varied according to the silver nanocrystal concentration and the test microorganism.

scholarly journals In vitro Antimicrobial Potential of Samples From the Leaves and Fruits of Medicinally Important Melia azedarach

2021 ◽  
Vol 64 (2) ◽  
pp. 109-115
Author(s):  
Jehan Bakht ◽  
Ayesha Bukhari ◽  
Arshad Iqbal ◽  
Mohammad Shafi
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Antimicrobial Activities ◽  
Melia Azedarach ◽  
Klebsiella Pneumonia ◽  
Gram Negative ◽  
Antibacterial And Antifungal Activities ◽  
Antibacterial And Antifungal ◽  
Micro Organisms

Different solvent extracted samples obtained from the leaves and fruits of Melia azedarach were investigated for their antibacterial and antifungal activities. All the extracts from both tissues sources showed varying degrees of antimicrobial activities. Ethyl acetate and n-butanol extracts of both tissues inhibited the growth of the tested micro-organisms at all concentrations. N-hexane extracted fractions of the leaves reduced the activity of Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa at all concentrations, while no growth inhibition was recorded against Klebsiella pneumonia and Candida albicans. Crude methanolic extract from the leaves tissues showed activity against all the tested microbial species and highest susceptibility was noted against Bacillus subtilis. In case of leaves, the most susceptible bacteria were Bacillus subtilis (gram positive) and Klebsiella pneumonia (gram negative) was the most resistant one. In case of fruits extracts, the most susceptible bacteria were Klebsiella pneumonia (gram negative) and Escherichia coli (gram negative) was the most resistant one.  

scholarly journals Effect of Optimization Factors on the Production of Bacillus subtilis and Escherichia coli Synthesized Silver Nanoparticles

2021 ◽  
pp. 39-47
Author(s):  
C. Chi-Nwankwo ◽  
J. N. Ogbulie ◽  
C. O. Akujobi
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Bacillus Subtilis ◽  
Negative Slope ◽  
Sharp Decline ◽  
Temperature Variations ◽  
E Coli ◽  
Extracellular Biosynthesis ◽  
Exponential Increase ◽  
Standard Procedures

The recent discovery of silver nanoparticles and their production from Bacillus subtilis and Escherichia coli have enhanced optimization attempts. Extracellular biosynthesis of silver nanoparticles using the Bacillus subtilis and Escherichia coli cultured supernatants was done according to standard procedures. Optimization of the production of silver nanoparticles was done in a 3 X 3 (three factors) design involving temperature (25, 30 and 35 degrees), pH (6, 7 and 8), and time of incubation (24, 48 and 72 Hours) in a total of 15 non-randomized runs. The result showed a sharp decline in the synthesis of B. subtilis silver nanoparticles (BNP) within the first 40 hours but attained steady optimization between 40 – 60 mins. An exponential increase in BNP synthesis was observed between pH 6 – 7 with a slight decline observed between pH 7 – 8. An increase in temperature from 25-300C resulted in a decrease in the production of BNP while the production of BNP increased over 30-350C. An initial lag in Escherichia coli synthesized silver nanoparticle (ENP) synthesis was observed with temperature variations. ENP synthesis maintained an exponential increase up to pH 7 but decreased with 7>pH≤8. The results showed that the increase in temperature resulted in a gradual decrease in production of ENP producing a negative slope. Therefore, the variations in optimization factors of silver nanoparticles produced from both B. subtilis and E. coli led to improved production.

scholarly journals Antibacterial Effect of Silver Nanoparticles on Klebsiella spp

2020 ◽  
Vol 1 (2) ◽  
pp. 8-15
Author(s):  
Gislanne Stéphanne Estevam da Silva ◽  
Rivaldo Leon Bezerra Cabral ◽  
Nathalie de Sena Pereira ◽  
José Heriberto Oliveira do Nascimento ◽  
Dany G kramer
Keyword(s):  
Silver Nanoparticles ◽  
Bacterial Resistance ◽  
Brain Heart Infusion ◽  
Trisodium Citrate ◽  
Antimicrobial Activities ◽  
Positive Control ◽  
Negative Control ◽  
In Vitro Tests ◽  
Klebsiella Spp

Silver nanoparticles (AgNP) can be incorporated into medical devices, such as tissues, to circumvent bacterial resistance such as Klebsiella spp, which can lead to skin and mucosal infections. Thus, the aim of the present study was to synthesize silver nanoparticles for later incorporation into cotton fabrics and in vitro tests against Klebsiella spp. The AgNP colloidal solution was synthesized (AgNO3 - 0.1 mM, 100 mM trisodium citrate, polyvinylpyrrolidone - 0.24 g, H2OH2) and then impregnated into the cotton fabric pretreated with poly diallyl dimethylammonium chloride (PDDA) of 100/500 tissue, shaken for 30 minutes). The material produced was analyzed by the FTIR; DLS and reflectance spectroscopy. The tests of the antimicrobial activities were by the microdilution technique against Klebsiella spp, in tubes containing Brain Heart Infusion (BHI), with the solution of silver (1); Tissue containing AgNP - 4 mm (2); Negative control (3) and positive control - ceftriaxone (4). Regarding MIC, the inhibitory activity occurred of the dilutions between 1/2 and 1/16. The AgNP particles had an average size of 24.75 nm. As synthesized AgNPs demonstrate the excellent antimicrobial activity against Klebsiella spp, with special emphasis on applications in nanotechnology and nanomedicine, targeting multiresistant antibiotic bacteria.

scholarly journals Preventive antimicrobial action and tissue architecture ameliorations of Bacillus subtilis in challenged broilers

2021 ◽  
Vol 14 (2) ◽  
pp. 523-536
Author(s):  
Essam S. Soliman ◽  
Rania T. Hamad ◽  
Mona S. Abdallah
Keyword(s):  
Bacillus Subtilis ◽  
Broiler Chickens ◽  
Trichophyton Mentagrophytes ◽  
Antimicrobial Activities ◽  
Lymphoid Hyperplasia ◽  
Bursa Of Fabricius ◽  
Tissue Architecture ◽  
E Coli

Background and Aim: Probiotics improve intestinal balance through bacterial antagonism and competitive exclusion. This study aimed to investigate the in vitro antimicrobial activity, as well as the in vivo preventive, immunological, productive, and histopathological modifications produced by probiotic Bacillus subtilis. Materials and Methods: The in vitro antimicrobial activities of B. subtilis (5×106 CFU/g; 0.5, 1.0*, 1.5, and 2.0 g/L) were tested against Escherichia coli O157: H7, Salmonella Typhimurium, Candida albicans, and Trichophyton mentagrophytes after exposure times of 0.25, 0.5, 1, and 2 h using minimal inhibitory concentration procedures. A total of 320 1-day-old female Ross broiler chickens were divided into five groups. Four out of the five groups were supplemented with 0.5, 1.0*, 1.5, and 2.0 g/L probiotic B. subtilis from the age of 1 day old. Supplemented 14-day-old broiler chickens were challenged with only E. coli O157: H7 (4.5×1012 CFU/mL) and S. Typhimurium (1.2×107 CFU/mL). A total of 2461 samples (256 microbial-probiotic mixtures, 315 sera, 315 duodenal swabs, and 1575 organs) were collected. Results: The in vitro results revealed highly significant (p<0.001) killing rates at all-time points in 2.0 g/L B. subtilis: 99.9%, 90.0%, 95.6%, and 98.8% against E. coli, S. Typhimurium, C. albicans, and T. mentagrophytes, respectively. Broilers supplemented with 1.5 and 2.0 g/L B. subtilis revealed highly significant increases (p<0.01) in body weights, weight gains, carcass weights, edible organs' weights, immune organs' weights, biochemical profile, and immunoglobulin concentrations, as well as highly significant declines (p<0.01) in total bacterial, Enterobacteriaceae, and Salmonella counts. Histopathological photomicrographs revealed pronounced improvements and near-normal pictures of the livers and hearts of broilers with lymphoid hyperplasia in the bursa of Fabricius, thymus, and spleen after supplementation with 2.0 g/L B. subtilis. Conclusion: The studies revealed that 1.5-2.0 g of probiotic B. subtilis at a concentration of 5×106 CFU/g/L water was able to improve performance, enhance immunity, and tissue architecture, and produce direct antimicrobial actions.

scholarly journals Unstable association in vitro between donor and recipient DNA in Bacillus subtilis

1982 ◽  
Vol 152 (1) ◽  
pp. 275-283
Author(s):  
J Van Randen ◽  
K Wiersma ◽  
G Venema
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Gradient Centrifugation ◽  
Cross Linking ◽  
Dna Fragments ◽  
Dna Complexes ◽  
Cscl Gradient ◽  
Donor Moiety

In addition to stable donor-recipient DNA complexes, unstable complexes between donor and recipient DNA were formed in vitro with Bacillus subtilis. Whereas the stable complexes survived CsCl gradient centrifugation at pH 11.2 and phenol plus sodium p-aminosalicylate extraction with 0.17 M NaCl, the unstable complexes dissociated during these manipulations. The donor moiety from the unstable complexes remained associated with the recipient DNA during phenol plus sodium p-aminosalicylate treatment at 0.85 M NaCl. The unstable complexes could be stabilized artificially by cross-linking with 4,5',8-trimethylpsoralen. Dissociation of the complexes during CsCl gradient centrifugation could be prevented by centrifuging at pH 10. Heterologous DNA fragments derived from phage H1 DNA appeared to be unable to form complexes with the recipient B. subtilis DNA. Unstable complexes were also formed with Escherichia coli DNA, although under all conditions tested, more complex was detectable by using homologous B. subtilis DNA.

Guanidinium and phosphonium scaffolds loaded with silver nanoparticles: synthesis, characterization, in vitro assessment of the antibacterial potential and toxicity

2021 ◽  
Author(s):  
M. N. Gorbunova ◽  
L.M. Lemkina ◽  
A.I. Nechaev
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Uv Spectroscopy ◽  
Planktonic Cells ◽  
Silver Nanocomposites ◽  
Nanoparticles Synthesis ◽  
In Vitro Assessment ◽  
Xrd Techniques ◽  
Antibacterial Potential

Abstract New silver nanocomposites based on polysulfones of 2,2-diallyl-1,1,3,3-tetraethylguanidiniumchloride [poly(AGC-SO2)], tris(diethylamino)diallylaminophosphonium tetrafluoroborate [poly(DAAP-BF4-SO2)] and chloride [poly(DAAP-Cl-SO2)] have been developed. UV- spectroscopy, SEM and XRD techniques were used to characterize the formation of silver nanoparticles in copolymers. Antibacterial action of new silver nanocomposites on S. epidermidis 33 and Escherichia coli (planktonic cells and biofilms) was studied. The silver nanocomposites strongly inhibited biofilms formation of S. epidermidis 33 and Escherichia coli. The silver nanocomposites based on phosphonium polysulfones have a significant cytotoxic activity against RD and MS line cells.

scholarly journals Polyurethane Microstructures-a Good or Bad in vitro Partner for the Isoflavone Genistein?

2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Corina Danciu ◽  
Florin Borcan ◽  
Codruta Soica ◽  
Istvan Zupko ◽  
Erzsébet Csányi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Salmonella Enteritidis ◽  
Practical Application ◽  
Preliminary Study ◽  
Micro Structures

In recent years polyurethane microstructures (PM) have gained increasing attention in the pharmaceutical field due to the importance of their practical application. Since finding that such a formulation with genistein could improve its applications, we have conducted a preliminary study regarding the in vitro antiproliferative (MCF7, MDA-MB-231 and T47D) and antimicrobial ( Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis (D), Bacillus subtilis, B. cereus, and Candida albicans) activity in order to test whether polyurethane micro structuresre present a good option for further modulation of genistein's bioavailability. It was concluded that the polyurethane micro structures are a bad in vitro partner for the isoflavone genistein.

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