scholarly journals Differential Damage in Bacterial Cells by Microwave Radiation on the Basis of Cell Wall Structure

2000 ◽  
Vol 66 (5) ◽  
pp. 2243-2247 ◽  
Author(s):  
Im-Sun Woo ◽  
In-Koo Rhee ◽  
Heui-Dong Park
Keyword(s):  
Microwave Radiation ◽  
Sodium Dodecyl ◽  
Cell Suspensions ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Dramatic Reduction ◽  
Severe Damage ◽  
Final Temperature ◽  
E Coli ◽  
Scanning Electron

ABSTRACT Microwave radiation in Escherichia coli andBacillus subtilis cell suspensions resulted in a dramatic reduction of the viable counts as well as increases in the amounts of DNA and protein released from the cells according to the increase of the final temperature of the cell suspensions. However, no significant reduction of cell density was observed in either cell suspension. It is believed that this is due to the fact that most of the bacterial cells inactivated by microwave radiation remained unlysed. Scanning electron microscopy of the microwave-heated cells revealed severe damage on the surface of most E. coli cells, yet there was no significant change observed in the B. subtilis cells. Microwave-injuredE. coli cells were easily lysed in the presence of sodium dodecyl sulfate (SDS), yet B. subtilis cells were resistant to SDS.

scholarly journals Adhesion ofE. coliBacteria Cells to Prosthodontic Alloys Surfaces Modified by TiO2Sol-Gel Coatings

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Katarzyna Banaszek ◽  
Witold Szymanski ◽  
Bożena Pietrzyk ◽  
Leszek Klimek
Keyword(s):  
Titanium Dioxide ◽  
Bacterial Adhesion ◽  
Culture Medium ◽  
Bacterial Culture ◽  
Bare Metal ◽  
Bacterial Cells ◽  
E Coli ◽  
Modified Surfaces ◽  
Bare Substrate ◽  
Scanning Electron

The evaluation of the degree of bacteriaE. coliadhesion to modified surfaces of the chosen prosthodontic alloys was presented. The study was carried out on Co-Cr (Wironit), Ni-Cr (Fantocer), and Fe-Cr-Ni (Magnum AN) alloys. Bare substrate as a control and titanium dioxide coated samples were used. The samples were placed for 24 hours in bacterial culture medium. After incubation period, a number of bacterial cells were evaluated by scanning electron microscope. The study revealed that modification of the alloy surfaces by titanium dioxide coating significantly decreases the amount of bacteria adhering to the surfaces and that additionally bare metal alloy substrates have a different degree of susceptibility to bacterial adhesion.

Alternative to Nitrites as Antibacterial Agents Against Clostridium sporogenes

2018 ◽  
Vol 17 (3) ◽  
pp. 242-248
Author(s):  
Zhang Zhi-Guo ◽  
Sun Di ◽  
Wang Mei-Lin
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Normal Growth ◽  
Food Preservation ◽  
Cell Membrane Permeability ◽  
Nitroso Compounds ◽  
Wall Structure ◽  
Ion Leakage ◽  
Bacterial Cells ◽  
Clostridium Sporogenes

Microbial spoilage is one of the key challenges to food preservation and safety. Sodium nitrite, the commonly used antibacterial, is associated with the generation of nitroso compounds known to impose a number of health risks including cancer. In this article, we report a comparison of a number of food-grade antibacterials, not known to generate nitroso compounds, for the inhibition of Clostridium sporogenes. These include e-poly-lysine, potassium cinnamate, chitosan, and glycerol monolaurate. We examined the effects of these agents alone and in combination on cell morphology, cell wall, cell membrane permeability, and bacterial proteins of C. sporogenes. The results show that these agents primarily act to inhibit C. sporogenes growth during log phase. Further analysis with flow cytometry and scanning electron microscopy revealed that the compound can induce changes to the morphology of C. sporogenes cells and, more significantly, to the internal structure of the cells. Treatment of C. sporogenes with the compound inhibited the normal growth of bacterial cells by damaging their wall structure and increasing their wall permeability. The changing pattern of electric conductivity indicated that the compound destroyed cytoplasmic membranes and resulted in ion leakage. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of soluble proteins concluded that the compound can destroy bacterial cells by altering their proteins.

scholarly journals Moringa oleifera functionalised sand – reuse with non-ionic surfactant dodecyl glucoside

2017 ◽  
Vol 15 (6) ◽  
pp. 863-872 ◽  
Author(s):  
Frances E. Williams ◽  
Andrew K. Lee ◽  
Sanaz Orandi ◽  
Sarah K. Sims ◽  
David M. Lewis
Keyword(s):  
Moringa Oleifera ◽  
Sodium Dodecyl ◽  
Bacterial Attachment ◽  
Polluted Water ◽  
Ionic Surfactant ◽  
Treatment Technique ◽  
Bacterial Cells ◽  
E Coli ◽  
Subsequent Loss ◽  
Seed Extracts

Abstract Moringa oleifera seeds are well known for their ability to cause flocculation in turbid water and facilitate bacterial inhibition. These effects are due to the cationic polypeptide MO2.1, which affects the surface charge of suspended particles and causes lysis of bacterial cells. However, the attachment of bacteria to MO2.1 prevents further bacterial attachment, reducing the effectiveness of the seeds. This research investigated the effect of surfactants on functionality and reuse of Moringa seeds to develop a sustainable water treatment technique. The seed extracts (MO2.1) were used with a functionalised sand system, and the sands were exposed to commercially available (ionic and non-ionic) surfactants, dodecyl glucoside and sodium dodecyl sulfate. Artificially polluted water contaminated with Escherichia coli was used to evaluate the efficiency of the system. The non-ionic surfactant was found to be effective at separating E. coli from the functionalised sand without the detachment of the MO2.1 and subsequent loss of the system efficiency. This was successfully repeated four times. The results demonstrated a sustainable, reusable technique to inhibit bacterial contamination in water.

scholarly journals Humidity-Dependent Bacterial Cells Functional Morphometry Investigations Using Atomic Force Microscope

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Hike Nikiyan ◽  
Alexey Vasilchenko ◽  
Dmitry Deryabin
Keyword(s):  
Cell Wall ◽  
Relative Humidity ◽  
Morphological Properties ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Wall Roughness ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Wide Range

The effect of a relative humidity (RH) in a range of 93–65% on morphological and elastic properties ofBacillus cereusandEscherichia colicells was evaluated using atomic force microscopy. It is shown that gradual dehumidification of bacteria environment has no significant effect on cell dimensional features and considerably decreases them only at 65% RH. The increasing of the bacteria cell wall roughness and elasticity occurs at the same time. Observed changes indicate that morphological properties ofB. cereusare rather stable in wide range of relative humidity, whereasE. coliare more sensitive to drying, significantly increasing roughness and stiffness parameters at RH 84% RH. It is discussed the dependence of the response features on differences in cell wall structure of gram-positive and gram-negative bacterial cells.

scholarly journals When Beneficial Biofilm on Materials Is Needed: Electrostatic Attachment of Living Bacterial Cells Induces Biofilm Formation

2021 ◽  
Vol 8 ◽  
Author(s):  
Dmitrii Deev ◽  
Iaroslav Rybkin ◽  
Tomaž Rijavec ◽  
Aleš Lapanje
Keyword(s):  
Biofilm Formation ◽  
Bacterial Attachment ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Microbial Composition ◽  
E Coli ◽  
Environmental Bacteria ◽  
Artificial Biofilm ◽  
Biofilm Prevention

Bacterial attachment is crucial in many biotechnological applications, but many important bacterial strains cannot form biofilms. Biofilms can damage materials, and current strategies to manage biofilms are focused on inhibition and removal of biofilm. Biofilm formation is inevitable when materials are exposed to microbes and instead of biofilm prevention, we propose management of microbial composition by formation of biofilms with beneficial microbes. Since bacteria need to overcome a high repulsive force to attach to the surface and later to grow and multiply on it, electrostatic modification of the surfaces of cells or the material by polyelectrolytes (PE) was used in our approach, enabling efficient attachment of viable bacterial cells. Since highly positively charged PEs are known to be bactericidal, they were acetylated to reduce their toxicity, while preserving their net positive charge and ensuring cell viability. In our study bacterial strains were selected according to their intrinsic capability of biofilm formation, their shape variety and cell wall structure. These strains were tested to compare how the artificially prepared vs. natural biofilms can be used to populate the surface with beneficial bacteria. Using an artificial biofilm constructed of the potentially probiotic isolate Bacillus sp. strain 25.2. M, reduced the attachment and induced complete inhibition of E. coli growth over the biofilm. This study also revealed that the modification of the surfaces of cells or material by polyelectrolytes allows the deposition of bacterial cells, biofilm formation and attachment of biofilm non-forming cells onto surfaces. In this way, artificial biofilms with extended stability can be constructed, leading to selective pressure on further colonization of environmental bacteria.

A Scanning Electron Microscopic Study of Pro-Vascular Cellular Morphology in Chaetophora Incressata

1985 ◽  
Vol 43 ◽  
pp. 638-639
Author(s):  
A. E. Hotchkiss ◽  
A. T. Hotchkiss ◽  
R. P. Apkarian
Keyword(s):  
Green Algae ◽  
Vascular Plants ◽  
Vascular System ◽  
Higher Plants ◽  
Wall Structure ◽  
Electron Microscopic ◽  
Physiological Processes ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.

Toxic Effect of 2-ethyl (bicyclo[2.2.1] heptane) on Bacterial Cells

2019 ◽  
Vol 35 (6) ◽  
pp. 67-72 ◽  
Author(s):  
I.V. Manukhov ◽  
L.S. Yaguzhinsky ◽  
M.V. Bermeshev ◽  
M.A. Zisman ◽  
V.G. Pevgov ◽  
...  
Keyword(s):  
Toxic Effect ◽  
Atmospheric Oxygen ◽  
Inducible Promoter ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Unique Identifier ◽  
E Coli ◽  
Lux Biosensors ◽  
High Level ◽  
Ministry Of Higher Education

Toxic effect of 2-ethylnorbornane (2-ethyl(bicyclo[2.2.1]heptane) (EBH)) on bacteria has been studied using the E. coli pRecA-lux and E. coli pKatG- lux cells as lux-biosensors. It was shown that the addition of EBH to the incubation medium leads to death and growth retardation, high level oxidative stress and DNA damage in E. coli cells. It is assumed that the oxidation of EBH with atmospheric oxygen causes the formation of reactive oxygen species in the medium, which makes a major contribution to the toxicity of this substance. biosensor, luciferase, bioluminescence, inducible promoter, PrecA, PkatG The authors are grateful to Stanislav Filippovich Chalkin for the development of interdisciplinary ties in the scientific community. The work was financially supported by the Ministry of Higher Education and Science of Russia (Project Unique Identifier RFMEFI60417X0181, Agreement No. 14.604.21.0181 of 26.09.2017).

Structure of the O-chain polysaccharide of the phenol-phase soluble lipopolysaccharide of Escherichia coli 0:157:H7

1986 ◽  
Vol 64 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Malcolm B. Perry ◽  
Leann MacLean ◽  
Douglas W. Griffith
Keyword(s):  
Escherichia Coli ◽  
Brucella Abortus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Extraction Procedure ◽  
Periodate Oxidation ◽  
Cross Reactivity ◽  
E Coli ◽  
Structure Formula ◽  
Phenol Water

The phenol-phase soluble lipopolysaccharide isolated from Escherichia coli 0:157 by the hot phenol–water extraction procedure was shown by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, periodate oxidation, methylation, and 13C and 1H nuclear magnetic resonance studies to be an unbranched linear polysaccharide with a tetrasaccharide repeating unit having the structure:[Formula: see text]The serological cross-reactivity of E. coli 0:157 with Brucella abortus, Yersinia enterocolitica (serotype 0:9), group N Salmonella, and some other E. coli species can be related immunochemically to the presence of 1,2-glycosylated N-acylated 4-amino-4,6-dideoxy-α-D-mannopyranosyl residues in the O-chains of their respective lipopolysaccharides.

scholarly journals Macrolide Resistance Gene mreA ofStreptococcus agalactiae Encodes a Flavokinase

2001 ◽  
Vol 45 (8) ◽  
pp. 2280-2286 ◽  
Author(s):  
Gervais Clarebout ◽  
Corinne Villers ◽  
Roland Leclercq
Keyword(s):  
High Performance ◽  
Shuttle Vector ◽  
Sodium Dodecyl ◽  
Macrolide Resistance ◽  
Upstream Region ◽  
Flavin Mononucleotide ◽  
Active Efflux ◽  
Fourfold Increase ◽  
E Coli ◽  
Multidrug Efflux Pumps

ABSTRACT The mreA gene from Streptococcus agalactiae COH31 γ/δ, resistant to macrolides and clindamycin by active efflux, has recently been cloned inEscherichia coli, where it was reported to confer macrolide resistance (J. Clancy, F. Dib-Hajj, J. W. Petitpas, and W. Yuan, Antimicrob. Agents Chemother. 41:2719–2723, 1997). Cumulative data suggested that the mreA gene was located on the chromosome of S. agalactiae COH31 γ/δ. Analysis of the deduced amino acid sequence of mreArevealed significant homology with several bifunctional flavokinases/(flavin adenine dinucleotide (FAD) synthetases, which convert riboflavin to flavin mononucleotide (FMN) and FMN to FAD, respectively. High-performance liquid chromatography experiments showed that the mreA gene product had a monofunctional flavokinase activity, similar to that of RibR from Bacillus subtilis. Sequences identical to those of the mreA gene and of a 121-bp upstream region containing a putative promoter were detected in strains of S. agalactiae UCN4, UCN5, and UCN6 susceptible to macrolides. mreA and its allele from S. agalactiae UCN4 were cloned on the shuttle vector pAT28. Both constructs were introduced into E. coli, where they conferred a similar two- to fourfold increase in the MICs of erythromycin, spiramycin, and clindamycin. The MICs of a variety of other molecules, including crystal violet, acriflavin, sodium dodecyl sulfate, and antibiotics, such as certain cephalosporins, chloramphenicol, doxycycline, nalidixic acid, novobiocin, and rifampin, were also increased. In contrast, resistance to these compounds was not detected when the constructs were introduced into E. faecalis JH2–2. In conclusion, the mreA gene was probably resident in S. agalactiae and may encode a metabolic function. We could not provide any evidence that it was responsible for macrolide resistance in S. agalactiae COH31 γ/δ; broad-spectrum resistance conferred by the gene in E. coli could involve multidrug efflux pumps by a mechanism that remains to be elucidated.

One-Step Preparation of Competent E. coli: Transformation and Storage of Bacterial Cells in the Same Solution

2021 ◽  
Vol 2021 (11) ◽  
pp. pdb.prot101212 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook
Keyword(s):  
Escherichia Coli ◽  
Convenient Method ◽  
Plasmid Dna ◽  
Transformation Efficiency ◽  
Bacterial Cells ◽  
E Coli ◽  
One Step ◽  
And Storage

This protocol describes a convenient method for the preparation, use, and storage of competent Escherichia coli. The reported transformation efficiency of this method is ∼5 × 107 transformants/µg of plasmid DNA.

Sign in / Sign up

Export Citation Format

Share Document