Enhanced Antibacterial Activity of CeO2 Nanoparticles by Surfactants

2013 ◽  
Vol 11 (2) ◽  
pp. 781-785 ◽  
Author(s):  
Rosalia Cuahtecontzi-Delint ◽  
Miguel A Mendez-Rojas ◽  
Erick R Bandala ◽  
Marco A Quiroz ◽  
Sonia Recillas ◽  
...  
Keyword(s):  
Tween 80 ◽  
Ionic Surfactants ◽  
Toxic Response ◽  
Bacteria Growth ◽  
E Coli ◽  
Rich Media ◽  
Wastewater Systems ◽  
The Media ◽  
Triton X ◽  
Mic Value

Abstract CeO2 nanoparticles (NPs) were tested to assess their toxicity on Escherichia coli strain in the presence of non-ionic surfactants. The NPs were dispersed in water by sonication at different pH values and times then mixed with three different surfactants (i.e., Triton X-100, Polyvinyl Pyrrolidone (PVP) and Tween 80) with a concentration of 0.001% v/v. It was found that sonication favored dispersion of the material and produced particles having 100 nm sizes in average. The material show toxicity to E. coli at pH 7 when growth using only minimal M9 media; no toxic response was observed for bacteria growth in rich media. The toxic effect in minimal media was enhanced by adding any of the non-ionic surfactants to the media. The use of CeO2 plus surfactant decreased the minimal inhibitory concentration (MIC) value of E. coli. The highest effect was observed for addition of Tween 80, in this case MIC value was 0.150 mg mL–1 compared to 3 mg mL–1 of CeO2 alone (almost 20 times improvement). These findings suggest the importance of different substances that can interact with NPs, like surfactants, usually present in wastewater systems that may lead to undesirable unexpected toxic characteristics in materials usually considered as innocuous.

scholarly journals Effect of metal ions and chemical agents on the activity of endoglucanase GH5 exploited from goats-rumen bacterial metagenomic DNA data

2021 ◽  
Vol 19 (3) ◽  
pp. 509-517
Author(s):  
Nguyen Khanh Hoang Viet ◽  
Ha Thi Thuy Hoa ◽  
Truong Nam Hai ◽  
Do Thi Huyen
Keyword(s):  
Enzyme Activity ◽  
Metal Ions ◽  
Specific Binding ◽  
Tween 80 ◽  
Conserved Residues ◽  
E Coli ◽  
Chemical Agents ◽  
Gene Coding ◽  
The Stability ◽  
Triton X

A gene coding for GH5 endoglucanase exploited from metagnomic DNA data of bacteria in Vietnamese goats’ rumen was modularity structure including a catalytic module, a fibronectin-3 like module and an X module. The recombinant enzyme was sucessfully expressed in E. coli and purified.  To study the effect of some metal ions and chemicals on enzyme activity, in this study, we used some tools including Swiss-Prot, ProFunc, COFACTOR for prediction of enzyme structure and ligands interaction. The obtained results indicated that the most similar structure with enzyme had two conserved residues (Asp-190 và Asp-192) linked with Mn2+ within a radius of ~ 3.5 Å from the center of ion Mn2+ and enzyme molecule contained a disulphide bond. Experimental results for essessment of the effect of some metal ions (Ca2 +, Mn2 +, Mg2+, Ni2+, K+, Co2+, Cu2+, Zn2+, Fe3+) at the final concentration of 10 mM and of six common chemicals including SDS (1%), urea (1 µM), 2-mercaptoethanol (1 µM), EDTA (1 µM), tween 80 (1mM), triton X-100 (1 µM) showed that only Mn2+ increased enzyme activity slightly at concentration of 10 mM and two times at the concentration of 40 mM Mn2+. The Mn2+ has been identified as a specific binding agent may increase the stability and activity of endoglucanase GH5.

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Large Scale ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Reporter System ◽  
E Coli ◽  
Starting Point ◽  
High Concentrations ◽  
Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

scholarly journals Elucidation of Gram-Positive Bacterial Iron(III) Reduction for Kaolinite Clay Refinement

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3084
Author(s):  
Hao Jing ◽  
Zhao Liu ◽  
Seng How Kuan ◽  
Sylvia Chieng ◽  
Chun Loong Ho
Keyword(s):  
Iron Reduction ◽  
Growth Conditions ◽  
Cellular Interaction ◽  
Kaolin Clay ◽  
Media Composition ◽  
Gram Positive ◽  
Kaolinite Clay ◽  
Gram Positive Bacteria ◽  
Rich Media ◽  
The Media

Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field.

scholarly journals Improvement of the Culture Medium for the Dichlorvos-Ammonia (DV-AM) Method to Selectively Detect Aflatoxigenic Fungi in Soil

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 519 ◽  
Author(s):  
Kimiko Yabe ◽  
Haruna Ozaki ◽  
Takuya Maruyama ◽  
Keisuke Hayashi ◽  
Yuki Matto ◽  
...  
Keyword(s):  
Culture Medium ◽  
Agar Medium ◽  
Carbon Sources ◽  
Tween 80 ◽  
Selective Medium ◽  
Selective Detection ◽  
Aflatoxigenic Fungi ◽  
Aspergillus Nomius ◽  
Rhizopus Sp ◽  
Triton X

The dichlorvos-ammonia (DV-AM) method is a simple but sensitive visual method for detecting aflatoxigenic fungi. Here we sought to develop a selective medium that is appropriate for the growth of aflatoxigenic fungi among soil mycoflora. We examined the effects of different concentrations of carbon sources (sucrose and glucose) and detergents (deoxycholate (DOC), Triton X-100, and Tween 80) on microorganisms in soils, using agar medium supplemented with chloramphenicol. The results demonstrated that 5–10% sucrose concentrations and 0.1–0.15% DOC concentrations were appropriate for the selective detection of aflatoxigenic fungi in soil. We also identified the optimal constituents of the medium on which the normal rapid growth of Rhizopus sp. was completely inhibited. By using the new medium along with the DV-AM method, we succeeded in the isolation of aflatoxigenic fungi from non-agricultural fields in Fukui city, Japan. The fungi were identified as Aspergillus nomius based on their calmodulin gene sequences. These results indicate that the new medium will be useful in practice for the detection of aflatoxigenic fungi in soil samples including those from non-agricultural environments.

Influence of Surfactants on Biodegradation of Chlordane by Wood-Rotting Fungus

2013 ◽  
Vol 361-363 ◽  
pp. 908-911
Author(s):  
Peng Fei Xiao ◽  
Tie Xue You ◽  
Yu Zhen Song ◽  
Shan Ying ◽  
Jian Qiao Wang
Keyword(s):  
Liquid Medium ◽  
Degradation Rate ◽  
Solid Medium ◽  
Fungal Growth ◽  
Tween 80 ◽  
Positive Effects ◽  
Lower Effect ◽  
Triton X

Wood-rotting fungus,Phlebia lindtneriGB 1027, was tested in toxicity assays with three surfactants in order to select surfactants for degradation assays of chlordane. Tween 80 and Triton X-100 appeared to have lower effect on the fungal growth on solid medium, while higher effect of fungal growth was observed in solid medium with SDS. Tween 80 had positive effects both on the chlordane degradation and the fungal growth. When fungus was incubated on PDB liquid medium with Tween 80 of 10 CMC after 20 d, 78.6% of chlordane was removed. In the treatments with Triton X-100, this strain showed comparatively greatest degradation rate (70.8%) of chlordane at a concentration of 2 CMC. However, when Triton X-100 concentration was higher than 2 CMC (5 and 10 CMC), the enhancement for the biodegradation of chlordane decreased.

scholarly journals Fermentation and Extraction of Antibacterial Metabolite Using Streptomyces spp. Isolated from Taplejung, Nepal

2021 ◽  
Vol 26 (1) ◽  
pp. 8-15
Author(s):  
Shiv Nandan Sah ◽  
Ramesh Majhi ◽  
Sunil Regmi ◽  
Arjun Ghimire ◽  
Bhageshwor Biswas ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Salmonella Typhi ◽  
Soil Samples ◽  
E Coli ◽  
Primary Screening ◽  
Streptomyces Spp ◽  
Antibacterial Compound ◽  
Fermented Broth ◽  
Layer Chromatography ◽  
Mic Value

Realizing an increasing need for a novel antibiotic, this study was carried out to screen antibacterial metabolites producing actinomycetes from 15 soil samples collected from Taplejung. Antibacterial metabolites producing actinomycetes were confirmed by primary screening and secondary screening. Macroscopic, microscopic, and biochemical characteristics were used for presumptive identification of probable actinomycetes genera. The potential isolate was cultured in starch casein broth for production of possible antibacterial compound. The antibacterial compound was extracted from fermented broth using organic solvents like ethyl acetate, n-butanol, chloroform, dichloromethane, and methanol. Among 24 isolates, only one (T18) showed antibacterial activity against both Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Salmonella Typhi and Pseudomonas aeruginosa) test-bacteria. The isolate was considered as Streptomyces spp based on microscopy and various biochemical, and physiological characteristics. Extracted antibacterial metabolite showed antibacterial activity with a MIC value of 1.2 mg/mL against E. coli (ATCC 25922). The chromatogram in Thin Layer Chromatography showed only one spot exhibited by extract with Rf value 0.87 suggested that the isolate produced a compound that was completely different from the spot with Rf value 0.94 produced by gentamicin (standard). This study revealed the distribution of the potent antibacterial metabolite producing actinomycetes in the soils of Taplejung.

Electrochemical Detection of Bacteria Using Graphene Oxide Electrodeposited on Titanium Implants

2014 ◽  
Vol 96 ◽  
pp. 45-53 ◽  
Author(s):  
Sirinrath Sirivisoot ◽  
Yardnapar Parcharoen ◽  
Thomas J. Webster
Keyword(s):  
Electron Transfer ◽  
Graphene Oxide ◽  
Electrochemical Sensors ◽  
Direct Electron Transfer ◽  
Orthopedic Implants ◽  
Titanium Implants ◽  
Cyclic Voltammograms ◽  
Label Free ◽  
Bacteria Growth ◽  
E Coli

Graphene oxide was electrodeposited on titanium (Ti-GO) and anodized titanium (ATi-GO) as label-free sensors for the detection of challenging living organisms, specificallyEscherichia coli(E. coli) andStaphylococcus aureus(S. aureus). The graphene modification contributed to two sets of oxidation-reduction peaks in cyclic voltammograms (CVs) of bacteria growth on the electrode surfaces (ATi-GO) that resulted in increasing direct electron transfer and stimulating excretion of mediating molecules for higher electron transfer between electrodes and bacteria. Additionally, similar wave patterns of CVs were found whenE. coliorS. aureuswere grown and electrocatalyzed on ATi-GO. The results suggest that bacteria on titanium implant surfaces could be easily detected by using mediatorless ATi-GO sensors electrochemically. These finding open another interesting method in using ATi-GO asin situelectrochemical sensors for label-free, close to real-time detection of bacteria infection in orthopedic implants.

scholarly journals Subcellular location and properties of bactericidal factors from human neutrophils.

1986 ◽  
Vol 164 (5) ◽  
pp. 1407-1421 ◽  
Author(s):  
J E Gabay ◽  
J M Heiple ◽  
Z A Cohn ◽  
C F Nathan
Keyword(s):  
Protein S ◽  
Subcellular Location ◽  
Inhibitory Effect ◽  
Human Neutrophils ◽  
E Coli ◽  
Fractionation Scheme ◽  
Percoll Gradients ◽  
Nonionic Detergent ◽  
Almost All ◽  
Triton X

We examined the subcellular location of bactericidal factors (BF) in human neutrophils, using an efficient fractionation scheme. Nitrogen bomb cavitates of DIFP-treated PMN were centrifuged through discontinuous Percoll gradients, each fraction extracted with 0.05 M glycine, pH 2.0, and tested for the killing of Escherichia coli. greater than 90% of BF coisolated with the azurophil granules. After lysis of azurophils, 98% of azurophil-derived BF (ADBF) sedimented with the membrane. ADBF activity was solubilized from azurophil membrane with either acid or nonionic detergent (Triton X-100, Triton X-114). Bactericidal activity was linear with respect to protein concentration over the range 0.3-30 micrograms/ml. 0.1-0.3 microgram/ml ADBF killed 10(5) E. coli within 30 min at 37 degrees C. At 1.4 micrograms/ml, 50% of 2 X 10(5) bacteria were killed within 5 min. ADBF was effective between pH 5-8, with peak activity at pH 5.5. Glucose (20 mM), EDTA (1-25 mM), and physiologic concentrations of NaCl or KCl had little or no inhibitory effect on ADBF. ADBF killed both Gram-positive and Gram-negative virulent clinical isolates, including listeria, staphylococci, beta-hemolytic streptococci, and Pseudomonas aeruginosa. Thus, under these conditions of cell disruption, fractionation, extraction, and assay, almost all BF in human PMN appeared to be localized to the membrane of azurophilic granules as a highly potent, broad-spectrum, rapidly acting protein(s) effective in physiologic medium. Some of these properties appear to distinguish ADBF from previously described PMN bactericidal proteins.

Letter To The Editor

PEDIATRICS ◽  
1970 ◽  
Vol 46 (2) ◽  
pp. 316-316
Author(s):  
Ralph A. Franciosi
Keyword(s):  
E Coli ◽  
In Vitro Sensitivity ◽  
Letter To The Editor ◽  
Mueller Hinton ◽  
The Media ◽  
Interesting Development ◽  
Co2 Atmosphere

Thank you very much for your letter regarding my letter to the editor and for the responses from Drs. Eichenwald and Mortimer. One interesting development that could be added as an addendum to show the artificial atmosphere of in vitro sensitivity is the finding that since we stopped incubating our sensitivity plates in a CO2 atmosphere, we have noted that only 11.5% of E. coli are resistant to kanamycin and only 8% resistant to ampicillin. Our sensitivity media is Mueller-Hinton with a pH of approximately 7.4. Apparently incubatioii in a CO2 atmosphere, which decreases the pH of the media, interferes with the sensitivity of E. coli in particular to kanamycin and ampicillin.

Mechanism of Radioprotective Action of Tween 80 on E. coli

RADIOISOTOPES ◽  
1968 ◽  
Vol 17 (5) ◽  
pp. 203-207
Author(s):  
Yoiti TITANI ◽  
Yutaka KATSUBE
Keyword(s):  
Tween 80 ◽  
E Coli ◽  
Radioprotective Action
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