scholarly journals The Synergistic Effects of Rhamnolipids and Antibiotics Against Bacteria

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Ella Shusterman ◽  
Abigail Mottahedeh ◽  
Merideth McCarthy
Keyword(s):  
Burkholderia Pseudomallei ◽  
Bacterial Infections ◽  
Synergistic Effects ◽  
Genetically Modify ◽  
Cell Permeability ◽  
Slowing Down ◽  
Surface Active Properties ◽  
Zones Of Inhibition ◽  
Surface Active

Antibiotics are used to combat bacterial infections by slowing down and preventing the proliferation of bacteria. Antibiotic resistance is a threat to human health, attributed to its overuse and misuse. Altering the membrane permeability to induce antibiotic uptake may be an effective strategy used against both Gram-positive and Gram-negative infectious bacteria. Rhamnolipids (RLs) are biosurfactants produced by Pseudomonas aeruginosa. RLs surface-active properties operate by creating holes in bacterial cell membranes, increasing target cell permeability; allowing antibiotics to penetrate the cell.    Rhamnolipids enhance the effect of antibiotics by targeting the intracellular machinery of bacteria. This project tested the susceptibility of bacteria when exposed to antibiotics with and without the addition of RLs, to quantitatively determine if RLs increase antibiotic potency. By analyzing the zones of inhibition data, the results demonstrated that RLs potentiated the antibiotics. Notably, kanamycin coupled with RLs had the most effect inhibiting bacterial growth.  To further assess rhamnolipid biosynthesis, a BLAST search was performed exclusively on two genes, rhlA and rhlB. These genes code for the production of two proteins necessary for rhamnolipids. The search indicated a 48% correlation with putative proteins found in Burkholderia pseudomallei. Therefore, based on the experimental results and the BLAST analysis, further research should be conducted to explore the possible role of using rhamnolipids as antibiotic enhancers. Specifically, future experiments could focus on isolating the putative proteins of B.pseudomallei to genetically modify E.coli. Furthermore, isolated studies analyzing the genes of proteins to determine their role in the pathogenicity of Burkholderia species.

Lignin from Hydrolyzed Wood By-Product as an Eco-Friendly Emulsion Stabilizer

2017 ◽  
Author(s):  
Sandra Livcha ◽  
Galia Shulga ◽  
Elina Zhilinska ◽  
Brigita Neiberte ◽  
Anrijs Verovkins ◽  
...  
Keyword(s):  
Wood Residue ◽  
Lignin Concentration ◽  
Surface Active Properties ◽  
Surface Active ◽  
Decreasing Ph ◽  
Alkaline Delignification ◽  
Soda Lignin ◽  
Hydrolysis Of ◽  
Electrostatic Mechanism

Aspen sulfur-free soda lignin was obtained as a result of alkaline delignification of hydrolyzed sawdust, a by-product of wood mechanical processing. The pre-hydrolysis of aspen sawdust was performed for enhancing the yield of lignin from the wood residue as well as to decrease the energy consumption of its milling for obtaining a filler for composites. The obtained lignin was characterized by a chemical composition, particle sizes and zeta potential values as well as by the surface-active properties at the air-water and oil-water interfaces. The surface tension of the lignin solutions at the air-water interface decreases with dropping 34 values and increasing lignin concentration due to hydrophobization of the lignin macromolecules, which is strengthened in the presence of a low molecular salt. The study of the obtained lignin as an emulsion stabilizer has shown that the O/W emulsion stabilized with alkaline lignin solutions with a concentration less than 0.1% demonstrates the highest stability with the formed smallest emulsion particles, having the highest negative charge, but the stabilization proceeds via the electrostatic mechanism. With decreasing pH values and increasing lignin concentration in the emulsion, the stabilization mechanism is more complicated with a growing role of steric factors.

scholarly journals Multinucleated Giant Cell Formation as a Portal to Chronic Bacterial Infections

2020 ◽  
Author(s):  
Jacob L. Stockton ◽  
Alfredo G. Torres
Keyword(s):  
Burkholderia Pseudomallei ◽  
Bacterial Infections ◽  
Cell Formation ◽  
Giant Cells ◽  
Clinical Findings ◽  
Giant Cell Formation ◽  
Similarities And Differences ◽  
And Function ◽  
Multinucleated Giant Cell Formation

This review provides a snapshot of chronic bacterial infections through the lens of Burkholderia pseudomallei; detailing its ability to establish multi-nucleated giant cells (MNGC) within the host, leading to the formation of pyogranulomatous lesions. We explore the role of MNGC in melioidosis disease progression and pathology by comparing the similarities and differences of melioidosis to tuberculosis, outlining the concerted events in pathogenesis that lead to MNGC formation, discussing the factors that influence MNGC formation and how they fit into clinical findings reported in chronic cases. Finally, we speculate about future models and techniques that can be used to delineate the mechanisms of MNGC formation and function.

scholarly journals Multinucleated Giant Cell Formation as a Portal to Chronic Bacterial Infections

2020 ◽  
Vol 8 (11) ◽  
pp. 1637
Author(s):  
Jacob L. Stockton ◽  
Alfredo G. Torres
Keyword(s):  
Burkholderia Pseudomallei ◽  
Bacterial Infections ◽  
Cell Formation ◽  
Giant Cells ◽  
Clinical Findings ◽  
Giant Cell Formation ◽  
Similarities And Differences ◽  
And Function ◽  
Multinucleated Giant Cell Formation

This review provides a snapshot of chronic bacterial infections through the lens of Burkholderia pseudomallei and detailing its ability to establish multi-nucleated giant cells (MNGC) within the host, potentially leading to the formation of pyogranulomatous lesions. We explore the role of MNGC in melioidosis disease progression and pathology by comparing the similarities and differences of melioidosis to tuberculosis, outline the concerted events in pathogenesis that lead to MNGC formation, discuss the factors that influence MNGC formation, and consider how they fit into clinical findings reported in chronic cases. Finally, we speculate about future models and techniques that can be used to delineate the mechanisms of MNGC formation and function.

Synergistic Methodology Based on Ion Exchange and Biodegradation Mechanisms Applied for Metal Complex Dye Removal from Waste Waters

2018 ◽  
Vol 69 (1) ◽  
pp. 38-44
Author(s):  
Nicoleta Mirela Marin ◽  
Olga Tiron ◽  
Luoana Florentina Pascu ◽  
Mihaela Costache ◽  
Mihai Nita Lazar ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Synergistic Effects ◽  
Freundlich Isotherm ◽  
White Rot ◽  
White Rot Fungus ◽  
Basic Anion Exchange Resin ◽  
Km Value ◽  
Points Of View ◽  
Basic Anion

This study investigates the synergistic effects of ion exchange and biodegradation methods to remove the Acid Blue 193 also called Gryfalan Navy Blue RL (GNB) dye from wastewater. Ion exchange studies were performed using a strongly basic anion exchange resin Amberlite IRA 400. The equilibrium was characterized by a kinetic and thermodynamic points of view, establishing that the sorption of the GNB dye was subject to the Freundlich isotherm model with R2 = 0.8710. Experimental results showed that the activated resin can removed up to 93.4% when the concentration of dye solution is 5.62�10-2 mM. The biodegradation of the GNB was induced by laccase, an enzyme isolated from white-rot fungus. It was also analyzed the role of pH and dye concentration on GNB biodegradation, so 5�10-2 mM dye had a maximum discoloration efficiency of 82.9% at pH of 4. The laccase showed a very fast and robust activity reaching in a few minutes a Km value of 2.2�10-1mM. In addition, increasing the GNB concentration up to 8�10-1 mM did not triggered a substrat inhibition effect on the laccase activity. Overall, in this study we proposed a mixt physicochemical and biological approach to enhance the GNB removal and biodegradability from the wastewaters and subsequently the environment.

Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

1991 ◽  
Vol 56 (10) ◽  
pp. 1993-2008
Author(s):  
S. Hanafi ◽  
G. M. S. El-Shafei ◽  
B. Abd El-Hamid
Keyword(s):  
Particle Size ◽  
Vapour Phase ◽  
Tricalcium Silicate ◽  
Active Centers ◽  
Thermally Activated ◽  
Grain Sizes ◽  
Intermediate Size ◽  
Surface Active ◽  
Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

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