scholarly journals Silver Nanoparticle Synthesis Using Monosaccharides and Their Growth Inhibitory Activity against Gram-Negative and Positive Bacteria

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Colin Pettegrew ◽  
Zheng Dong ◽  
M. Zubayed Muhi ◽  
Scott Pease ◽  
M. Abdul Mottaleb ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antimicrobial Properties ◽  
Nanoparticle Synthesis ◽  
Sem Analysis ◽  
Ag Nps ◽  
Gram Negative ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
Peptidoglycan Cell Wall ◽  
Wall Interaction

Using various monosaccharides as reductant, we synthesized Ag nanoparticles (NPs) in seconds employing the household microwave method described earlier. The Ag NPs containing colloidal solution showed distinctive colors with varying λmax. The sizes of the NPs formed varied significantly from 10 to 35 nm in good agreement with the localized plasmon resonance ranged from ~300 to ~600 nm. The antimicrobial properties of these NPs were compared in Gram-negative and positive bacteria in liquid culture. Gram-positive bacteria were highly susceptible compared to Gram-negative microbes—the additional lipopolysaccharide layer covering the peptidoglycan cell wall in the latter somewhat lessens the effect. The results indicated that larger NPs produced by glucose inhibited bacterial growth better than the smallest NPs produced by ribose. This may be attributed to the higher aggregation rate for larger NPs on cell wall. SEM analysis showed accumulation of NPs on cell surface and defect in budding, further supporting the cell wall interaction with Ag NPs. These observations suggested that the growth inhibition of Ag NPs is mediated by interfering with the bacterial cell wall peptidoglycan.

scholarly journals General principles for the formation and proliferation of a wall-free (L-form) state in bacteria

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Romain Mercier ◽  
Yoshikazu Kawai ◽  
Jeff Errington
Keyword(s):  
Cell Wall ◽  
Molecular Biology ◽  
Gram Negative Bacteria ◽  
Systematic Analysis ◽  
Gram Negative ◽  
Membrane Blebbing ◽  
Precursor Synthesis ◽  
Peptidoglycan Cell Wall ◽  
Synthetic Cells ◽  
Opening Up

The peptidoglycan cell wall is a defining structural feature of the bacterial kingdom. Curiously, some bacteria have the ability to switch to a wall-free or ‘L-form’ state. Although known for decades, the general properties of L-forms are poorly understood, largely due to the lack of systematic analysis of L-forms in the molecular biology era. Here we show that inhibition of peptidoglycan precursor synthesis promotes the generation of L-forms from both Gram-positive and Gram-negative bacteria. We show that the L-forms generated have in common a mechanism of proliferation involving membrane blebbing and tubulation, which is dependent on an altered rate of membrane synthesis. Crucially, this mode of proliferation is independent of the essential FtsZ based division machinery. Our results suggest that the L-form mode of proliferation is conserved across the bacterial kingdom, reinforcing the idea that it could have been used in primitive cells, and opening up its use in the generation of synthetic cells.

scholarly journals Transcriptomic Evaluation of Plant Growth Inhibitory Activity of Goniothalamin from the Malaysian Medicinal Plant Goniothalamus andersonii

2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Naoya Wasano ◽  
Tomoko Takemura ◽  
Raihan Ismil ◽  
Baki Bakar ◽  
Yoshiharu Fujii
Keyword(s):  
Cell Wall ◽  
Plant Growth ◽  
Medicinal Plant ◽  
Early Gene ◽  
Cell Wall Modification ◽  
Oxidative Stresses ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
Associated Proteins ◽  
Heat Response

Goniothalamin produced by the Malaysian medicinal plant, Goniothalamus andersonii J. Sinclair, strongly inhibits plant growth. However, its mode of action has not been characterized at the gene expression level. We conducted DNA microarray assay to analyze the changes in early gene responses of Arabidopsis thaliana seedlings. After a 6-h exposure to goniothalamin, we observed an upregulation of genes highly associated with heat response, and 22 heat shock protein ( AtHSP) genes were upregulated more than 50 fold. Together with these genes, we observed upregulation of the genes related to oxidative stress and protein folding. Also, the genes related to cell wall modification and cell growth, expansin ( AtEXPA) genes, were significantly downregulated. The results suggested that goniothalamin induces oxidative stresses and inhibits the expression of cell wall-associated proteins resulting in growth inhibition of Arabidopsis seedlings.

scholarly journals Simulations suggest a constrictive force is required for Gram-negative bacterial cell division

2018 ◽  
Author(s):  
Lam T. Nguyen ◽  
Catherine M. Oikonomou ◽  
H. Jane Ding ◽  
Mohammed Kaplan ◽  
Qing Yao ◽  
...  
Keyword(s):  
Cell Wall ◽  
Simulation System ◽  
Mechanistic Models ◽  
Bacterial Cells ◽  
Bacterial Cell Division ◽  
Cell Wall Synthesis ◽  
Gram Negative ◽  
Division Site ◽  
Cell Wall Remodeling ◽  
Peptidoglycan Cell Wall

AbstractTo divide, Gram-negative bacterial cells must remodel their peptidoglycan cell wall to a smaller and smaller radius at the division site, but how this process occurs remains debated. While the tubulin homolog FtsZ is thought to generate a constrictive force, it has also been proposed that cell wall remodeling alone is sufficient to drive membrane constriction, possibly via a make-before-break mechanism in which new hoops of cell wall are made inside the existing hoops (make) before bonds in the existing wall are cleaved (break). Previously, we constructed software, REMODELER 1, to simulate cell wall remodeling in rod-shaped bacteria during growth. Here, we used this software as the basis for an expanded simulation system, REMODELER 2, which we used to explore different mechanistic models of cell wall division. We found that simply organizing the cell wall synthesis complexes at the midcell was not sufficient to cause wall invagination, even with the implementation of a make-before-break mechanism. Applying a constrictive force at the midcell could drive division if the force was sufficiently large to initially constrict the midcell into a compressed state before new hoops of relaxed cell wall were incorporated between existing hoops. Adding a make-before-break mechanism could drive division with a smaller constrictive force sufficient to bring the midcell peptidoglycan into a relaxed, but not necessarily compressed, state.

scholarly journals Combination of Clove and Lemon Basil Essential Oils for Preservation of Chicken Meat

2020 ◽  
Author(s):  
D. Hartanti ◽  
N.A. Septiyaningrum ◽  
A. Hamad
Keyword(s):  
Essential Oils ◽  
Inhibitory Activity ◽  
Microbial Growth ◽  
Chemical Constituents ◽  
Antimicrobial Properties ◽  
Treatment Groups ◽  
Oxygenated Compounds ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
Single Use

Background: Clove and lemon basil are widely used in Indonesian culinary and known for their antimicrobial properties. This study was designed to identify the chemical constituents of single clove and lemon basil Essential Oils (EOs) as well as determine the potential of the combinations of both EO for preserving chicken meats. Methods: The compositions of clove and lemon basil EOs were evaluated with Gas Chromatography-Mass Spectrometer. Three different concentration ratios of the combination of clove and lemon basil EOs (2:0.2, 1:1, and 0.1:2% v/v) were prepared along with single clove and lemon basil EOs in a concentration of 1% v/v. Their potential preservation effect was evaluated by observing the reduction of the microbial growth on the meats by evaluating Optical Density (OD) of cultured bacterial suspensions during 15 days of refrigerated storage. Statistical analyses were conducted by SPSS Statistics v. 20. Results: The major constituents of clove EO were eugenol, β-caryophyllene, and αhumulene, while those of lemon basil were estragol, linalool, E-citral, and Z-citral. Both treatment groups and storage time affected significantly on ODs of the samples. Combination of these two EOs, particularly at the optimum ratio of 1:1%, showed the best microbial inhibitory activity, and delayed the sensorial changes of the meats for 12 days. Conclusion: The combinations of cloves and lemon basil EOs showed a better microbial growth inhibitory activity and preservation potential than those of the single use. This meat preservation effects might be related to the presence of high fractions of oxygenated compounds, mainly eugenol, Z-citral, and E-citral in both clove and lemon basil EOs.

scholarly journals Nanoparticle Synthesis from Biowaste and Its Potential as an Antimicrobial Agent

2021 ◽  
Author(s):  
Rishana Saffar ◽  
Athira PV ◽  
Kangkana Kalita ◽  
Suba G A Manuel ◽  
Pradeep N
Keyword(s):  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Nanoparticle Synthesis ◽  
Punica Granatum ◽  
Diffusion Method ◽  
Potential Candidate ◽  
Zone Of Inhibition ◽  
Ag Nps ◽  
Zno Nps ◽  
X Ray

Abstract Biosynthesized nanoparticles are gaining more importance because of their unique biological applications and can be synthesised using biowastes like fruit peels that acts as a better alternative against conventional physical and chemical methods. This work reports an ecofriendly, reliable and cost-effective synthesis of silver and zinc oxide nanoparticles (Ag and ZnO NPs) chemically and biologically using fresh peel extracts of Punica granatum and Musa acuminata. The synthesised nanoparticles were characterized using UV-Visible spectroscopy, X-ray Diffraction (XRD), Scanning electron microscopy (SEM) and Energy dispersive X-ray analysis (EDS). The size of chemically and biosynthesized Ag and ZnO NPs ranged around 12-20 nm and 0.4-24 nm respectively. Both biosynthesized Ag and ZnO NPs were found to be nanospheres whereas chemically synthesised ZnO NPs were nanoflakes and showed maximum absorbance in the range of 250-550nm. Antimicrobial properties of the synthesized nanoparticles were assessed by well diffusion method against Gram negative Escherichia coli and Gram-positive Bacillus subtilis. Biosynthesized Ag NPs were found to be more efficient against E. coli as compared to ZnO NPs wherein biosynthesized M. acuminata Ag NPs exhibiting maximum zone of inhibition (28.4±14.66mm). Similarly, biosynthesized ZnO NPs were more efficient against B. subtilis as compared to biosynthesized Ag NPs wherein biosynthesized P. granatum ZnO NPs exhibiting maximum zone of inhibition (14.08±3.03mm). Hence biosynthesized NPs can be exploited as a potential candidate for antimicrobial agents. Scientific and systematic use of biowaste for NPs synthesis could in turn result in a sustainable solution for waste management.

scholarly journals Antimicrobial Properties of the Polyaniline Composites against Pseudomonas aeruginosa and Klebsiella pneumoniae

2020 ◽  
Vol 11 (3) ◽  
pp. 59 ◽  
Author(s):  
Moorthy Maruthapandi ◽  
Arumugam Saravanan ◽  
John H. T. Luong ◽  
Aharon Gedanken
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Klebsiella Pneumoniae ◽  
Cell Walls ◽  
Antimicrobial Properties ◽  
Cell Lysis ◽  
Antimicrobial Activities ◽  
Sonochemical Method ◽  
Gram Negative ◽  
Polyaniline Composites

CuO, TiO2, or SiO2 was decorated on polyaniline (PANI) by a sonochemical method, and their antimicrobial properties were investigated for two common Gram-negative pathogens: Pseudomonas aeruginosa (PA) and Klebsiella pneumoniae (KP). Without PANI, CuO, TiO2, or SiO2 with a concentration of 220 µg/mL exhibited no antimicrobial activities. In contrast, PANI-CuO and PANI-TiO2 (1 mg/mL, each) completely suppressed the PA growth after 6 h of exposure, compared to 12 h for the PANI-SiO2 at the same concentration. The damage caused by PANI-SiO2 to KP was less effective, compared to that of PANI-TiO2 with the eradication time of 12 h versus 6 h, respectively. This bacterium was not affected by PANI-CuO. All the composites bind tightly to the negative groups of bacteria cell walls to compromise their regular activities, leading to the damage of the cell wall envelope and eventual cell lysis.

scholarly journals Synthesis of Silver Nanoparticles Using the UV-Irradiation Technique in an Antibacterial Application

2019 ◽  
Vol 54 (5) ◽  
Author(s):  
Ahmed Mahdi Rheima ◽  
Mahdi A. Mohammed ◽  
Shaimaa Hamed Jaber ◽  
Shahad Abbas Hameed
Keyword(s):  
Silver Nanoparticles ◽  
Uv Irradiation ◽  
Antimicrobial Properties ◽  
Ion Concentration ◽  
Gram Negative Bacteria ◽  
Ag Nps ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Irradiation Energy

The article describes a new way to the synthesis of silver nanoparticles based on UV-irradiation energy. Our technique allows for producing high quality and clean nanoparticles. Moreover, our photolysis approach allows us to synthesis silver nanoparticles (Ag NPs) with very low cost and short time. The nanostructures were characterized using X-ray diffraction, transmission electron spectroscopy and UV-visible spectrometer. Most of the Ag NPs are shown to be a hexagonal shape and some of them are a spherical shape. The average size of nanoparticles was calculated to be around 20.23 nm. The morphology, size, and ion concentration of the synthesized Ag NPs determine their absorbance and transmittance at the UV region of spectrum. Silver's antimicrobial properties are well known and due to their antimicrobial activity, silver nanoparticles become more important. Therefore, our synthesized Ag NPs were used against Staphylococcus aureus (Gram-positive bacteria) and E. coli (Gram-negative bacteria). The results show that the nanoparticles at a concentration of 0.2 mg/ml demonstrated a high activity of antimicrobials, resulting in a good inhibition for both grams positive and negative bacteria. However, the effect of Ag NPs on gram-positive bacteria is higher than gram-negative bacteria.

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Disinfection of Fruits with Activated Water

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Solutions ◽  
Antimicrobial Properties ◽  
The Other ◽  
Gram Negative Bacteria ◽  
High Antimicrobial Activity ◽  
Gram Negative ◽  
E Coli ◽  
Number Of Microorganisms ◽  
Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

Sign in / Sign up

Export Citation Format

Share Document