scholarly journals Combined Effect of Nitrofurantoin and Plant Surfactant on Bacteria Phospholipid Membrane

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2527
Author(s):  
Monika Rojewska ◽  
Wojciech Smułek ◽  
Krystyna Prochaska ◽  
Ewa Kaczorek
Keyword(s):  
Membrane Permeability ◽  
Adsorption Properties ◽  
Bacterial Cells ◽  
Phospholipid Membrane ◽  
High Concentration ◽  
Natural Surfactants ◽  
Wide Perspective ◽  
Environmental Bacteria ◽  
Achromobacter Sp ◽  
Saponaria Officinalis

Due to the increasing use of antibiotics, measures are being taken to improve their removal from the natural environment. The support of biodegradation with natural surfactants that increase the bioavailability of impurities for microorganisms that degrade them, raises questions about their effect on bacterial cells. In this paper we present analysis of the interaction of nitrofurantoin (NFT) and saponins from the Saponaria officinalis on the environmental bacteria membrane and the model phospholipid membrane mimicking it. A wide perspective of the process is provided with the Langmuir monolayer technique and membrane permeability test with bacteria. The obtained results showed that above critical micelle concentration (CMC), saponin molecules are incorporated into the POPE monolayer, but the NFT impact was ambiguous. What is more, differences in membrane permeability between the cells exposed to NFT in comparison to that of the non-exposed cells were observed above 1.0 CMC for Achromobacter sp. KW1 or above 0.5 CMC for Pseudomonas sp. MChB. In both cases, NFT presence lowered the membrane permeability. Moreover, the Congo red adhesion to the cell membrane also decreased in the presence of a high concentration of surfactants and NFT. The results suggest that saponins are incorporated into the bacteria membrane, but their sugar hydrophilic part remains outside, which modifies the adsorption properties of the cell surface as well as the membrane permeability.

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

Significance of External Carbon Sources on Simultaneous Removal of Nutrients from Wastewater

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1047-1055 ◽  
Author(s):  
N. F. Y. Tam ◽  
Y. S. Wong ◽  
G. Leung
Keyword(s):  
Sodium Acetate ◽  
Batch Reactor ◽  
Inorganic Nitrogen ◽  
Carbon Sources ◽  
Simultaneous Removal ◽  
Bacterial Cells ◽  
High Concentration ◽  
P Content ◽  
Carbon Substrates ◽  
Effective Source

Laboratory-scale studies were undertaken to examine the effects of easily-biodegradable organic substances upon the nutrient removal by a simulated sequencing batch reactor (SBR). The fill and react period of the SBR was 14 hours, including an instant fill, 7 hours aeration, 4 hours anoxic and 3 hours aeration period. Three kinds of commonly used carbon sources, namely methanol, glucose and sodium acetate, at the concentrations equivalent to theoretical COD values of 50, 100 and 150 mg O2 l-1 were added to each reactor prior to the anoxic stage. The results showed that the concentration of NH4+-N dropped from its initial 50 to 18 mg l-1 (64 % removal) during the first aeration period, with the NO3−-N content increased from 2 to 33 mg l−1. A 60% depletion of COD was also recorded in this period. Denitrification occurred during the anoxic period, higher amount of NO3−1-N was removed in the reactors supplemented with carbon substrates at the concentrations of 100 and 150 mg l-1. The final inorganic nitrogen content was less than 5 mg l-1 in the reactor supplemented with 150 mg l-1 sodium acetate. Simultaneous removal of phosphorus was reported in reactors supplied with high concentration of sodium acetate. In these reactors, large amount of P was released during the anoxic/anaerobic period but the released P was taken up by bacterial cells in the subsequent aeration stage, and the final P content was less than 1.5 mg l-1 (84 % removal was achieved). Among the three carbon sources used, sodium acetate was the most efficient and effective source in removing wastewater nutrients, followed by methanol, and glucose was the least reliable substrate.

scholarly journals Anaerobic reduction of hexavalent chromium by bacterial cells of Achromobacter sp. Strain Ch1

2008 ◽  
Vol 163 (6) ◽  
pp. 616-623 ◽  
Author(s):  
Wenjie Zhu ◽  
Liyuan Chai ◽  
Zemin Ma ◽  
Yunyan Wang ◽  
Haijuan Xiao ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Bacterial Cells ◽  
Achromobacter Sp ◽  
Anaerobic Reduction

Influence of Carvacrol and 1,8-Cineole on Cell Viability, Membrane Integrity, and Morphology of Aeromonas hydrophila Cultivated in a Vegetable-Based Broth

2015 ◽  
Vol 78 (2) ◽  
pp. 424-429 ◽  
Author(s):  
JOSSANA PEREIRA de SOUSA ◽  
KATARYNE ÁRABE RIMÁ de OLIVEIRA ◽  
REGINA CELIA BRESSAN QUEIROZ de FIGUEIREDO ◽  
EVANDRO LEITE de SOUZA
Keyword(s):  
Cell Viability ◽  
Membrane Permeability ◽  
Aeromonas Hydrophila ◽  
Membrane Integrity ◽  
Cell Membrane Permeability ◽  
Confocal Laser ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Transmission Electron ◽  
Cytoplasmic Content

This study investigated the effects of carvacrol (CAR) and 1,8-cineole (CIN) alone (at the MIC) or in combination at subinhibitory amounts (both at 1/8 MIC) on the cell viability, membrane permeability, and morphology of Aeromonas hydrophila INCQS 7966 (A. hydrophila) cultivated in a vegetable-based broth. CAR and CIN alone or in combination severely affected the viability of the bacteria and caused dramatic changes in the cell membrane permeability, leading to cell death, as observed by confocal laser microscopy. Scanning and transmission electron microscopy images of bacterial cells exposed to CAR or CIN or the mixture of both compounds revealed severe changes in cell wall structure, rupture of the plasma membrane, shrinking of cells, condensation of cytoplasmic content, leakage of intracellular material, and cell collapse. These findings suggest that CAR and CIN alone or in combination at subinhibitory amounts could be applied to inhibit the growth of A. hydrophila in foods, particularly as sanitizing agents in vegetables.

scholarly journals Combinatorial Antimicrobial Efficacy and Mechanism of Linalool Against Clinically Relevant Klebsiella pneumoniae

2021 ◽  
Vol 12 ◽  
Author(s):  
Shun-Kai Yang ◽  
Khatijah Yusoff ◽  
Mokrish Ajat ◽  
Chien-Yeong Wee ◽  
Polly-Soo-Xi Yap ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Klebsiella Pneumoniae ◽  
Membrane Permeability ◽  
Membrane Damage ◽  
Bacterial Membrane ◽  
Bacterial Cells ◽  
Bacterial Killing ◽  
Potential Measurement ◽  
Bacterial Surface ◽  
Electron Microscopies

Antibiotic–adjuvant combinatory therapy serves as a viable treatment option in addressing antibiotic resistance in the clinical setting. This study was carried out to assess and characterize the adjuvant potential and mode of action of linalool against carbapenemase-producing Klebsiella pneumoniae (KPC-KP). Linalool exhibited bactericidal activity alone (11,250 μg/ml) and in combination with meropenem (5,625 μg/ml). Comparative proteomic analysis showed significant reduction in the number of cytoplasmic and membrane proteins, indicating membrane damage in linalool-treated KPC-KP cells. Upregulation of oxidative stress regulator proteins and downregulation of oxidative stress-sensitive proteins indicated oxidative stress. Zeta potential measurement and outer membrane permeability assay revealed that linalool increases the bacterial surface charge as well as the membrane permeability. Intracellular leakage of nucleic acid and proteins was detected upon linalool treatment. Scanning and transmission electron microscopies further revealed the breakage of bacterial membrane and loss of intracellular materials. Linalool induced oxidative stress by generating reactive oxygen species (ROS) which initiates lipid peroxidation, leading to damage of the bacterial membrane. This leads to intracellular leakage, eventually killing the KPC-KP cells. Our study demonstrated that linalool possesses great potential in future clinical applications as an adjuvant along with existing antibiotics attributed to their ability in disrupting the bacterial membrane by inducing oxidative stress. This facilitates the uptake of antibiotics into the bacterial cells, enhancing bacterial killing.

scholarly journals THE MATRIX IS EVERYWHERE: CACO3 BIOMINERALIZATION BY THE BACILLUS LICHENIFORMIS PLANKTONIC CELLS

2020 ◽  
Author(s):  
Lyubov A. Ivanova ◽  
Darya A. Golovkina ◽  
Elena V. Zhurishkina ◽  
Yuri P. Garmay ◽  
Alexander Ye. Baranchikov ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Crystal Growth ◽  
Bacillus Licheniformis ◽  
Spatial Arrangement ◽  
Classical Pathway ◽  
Bacterial Cells ◽  
Planktonic Cells ◽  
High Concentration ◽  
Polymorphic Transformations ◽  
Traditional Role

ABSTRACTTo date, the mechanisms of CaCO3 nucleus formation and crystal growth induced by bacterial cells still remain debatable. Here, an insight on the role of planktonic cells of Bacillus licheniformis DSMZ 8782 in the biomineralization is presented. We showed that during 14-days bacterial growth in a liquid urea/Ca2+-containing medium the transformation of CaCO3 polymorphs followed the classical pathway “ACC-vaterite-calcite/aragonite”. By microscopic techniques, we detected the formation of extracellular matrix (ECM) around the cells at the stage of exponential growth and appearance of electron-dense inclusions at 24 h after the inoculation. The cells formed filaments and created a network, the nodes of which served as sites for further crystal growth. The ECM formation accompanied with the expression of proteins required for biofilm formation, the aldehyde/alcohol dehydrogenase, stress-associated Clp family proteins, and a porin family protein (ompA ortholog) associated with bacterial extracellular vesicles. We demonstrated that urea and CaCl2 acted as denaturing agents causing matrix formation in addition to their traditional role as a source of carbonate and Ca2+ ions. We showed that CaCO3 nucleation occured inside B. licheniformis cells and further crystal growth and polymorphic transformations took place in the extracellular matrix without attaching to the cell surface. The spatial arrangement of the cells was important for the active crystal growth and dependent on environmental factors. The extracellular matrix played a double role being formed as a stress response and providing a favorable microenvironment for biomineralization (a high concentration of ions necessary for CaCO3 crystal aggregation, fixation and stabilization).

scholarly journals Removal of Chromates and Sulphates by Mg/Fe LDH and Heterostructured LDH/Halloysite Materials: Efficiency, Selectivity, and Stability of Adsorbents in Single- and Multi-Element Systems

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1373 ◽  
Author(s):  
Jakub Matusik ◽  
Karolina Rybka
Keyword(s):  
Adsorption Properties ◽  
Small Extent ◽  
Minor Importance ◽  
Adsorption Efficiency ◽  
High Concentration ◽  
Lower Efficiency ◽  
Industrial Wastewaters ◽  
Column Adsorption ◽  
Double Hydroxides ◽  
Very High

Industrial wastewaters often contain mobile and toxic anions that cannot be removed by precipitation techniques and most known adsorbents. Layered double hydroxides (LDH) are excellent scavengers of anions; however, their use in real applications is of minor importance owing to their swelling behavior and high cost of production. The performed research shows the possibility of obtaining Mg/Fe LDH using natural magnesite. Moreover, heterostructured LDH/halloysite materials were synthesized. The adsorption efficiency of these materials was very high in both single- and multi-element systems, confirming the LDH selectivity. This was with the exception of wastewaters containing a high concentration of chlorides, which clearly hampered the removal of Cr(VI) and S(VI). The measurements indicated that LDH dissolution took place to a small extent (<10 wt%). The LDH/halloysite materials showed lower efficiency than the raw LDH; however, the clay presence has several benefits in terms of future applications: (i) it significantly reduces the pH, especially in contrast to the calcined LDH, which enables the reuse or safe disposal of purified water; (ii) it reduces swelling of the composite, which opens the possibility for applications in column adsorption; (iii) it induces dual adsorption properties through additional cation adsorption; and (iv) it substantially lowers the price of the adsorbent.

Surface properties of chitosan/montmorillonite films for biomedical applications

2020 ◽  
pp. 096739112096843
Author(s):  
Shih-Hang Chang ◽  
Ming-Han Hsieh
Keyword(s):  
Protein Adsorption ◽  
Functional Groups ◽  
Biomedical Applications ◽  
Composite Films ◽  
Adsorption Properties ◽  
High Concentration ◽  
Protein Assay ◽  
Metallic Implants ◽  
Protein Adhesion ◽  
Adsorption Concentration

In this study, we firstly investigated the surface and protein adsorption properties of montmorillonite (MMT)/chitosan (CS) composite films with various MMT/CS weight ratios for metallic implants coating applications. Bicinchoninic acid (BCA) protein assay results show that the neat CS film exhibits a high concentration of bovine serum albumin (BSA) protein adhesion because the abundant carbonyl and amide functional groups on the surface of the CS film easily form hydrogen bonds with the copious carboxylic acid groups on the surface of the BSA protein. The MMT/CS composite films with MMT/CS = 3, 5, 8, and 10 possess a much lower BSA adhesion concentration than that of the neat CS film, as some of the carbonyl and amide functional groups on the surface of the composite films are replaced by the –Si–O–Si and –Al–O–Al groups. Among these MMT/CS composite films, the film with MMT/CS = 5 exhibits the lowest BSA adsorption concentration because it possesses a higher MMT content than those with MMT/CS = 1 and 3 and a smoother and non-porous surface than those with MMT/CS = 8 and 10. According to our results, MMT/CS composite films with appropriate MMT/CS weight ratios exhibit better surface and protein adsorption properties than neat CS for biomedical applications.

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