scholarly journals Tuning cell surface charge in E. coli with conjugated oligoelectrolytes

2016 ◽  
Vol 7 (3) ◽  
pp. 2023-2029 ◽  
Author(s):  
Chelsea Catania ◽  
Alexander W. Thomas ◽  
Guillermo C. Bazan

Conjugated oligoelectrolytes intercalate into and associate with membranes, thereby changing the surface charge of microbes, as determined by zeta potential measurements.

2018 ◽  
Author(s):  
Wenfa Ng

Proteins and metabolites typically adsorb to bacterial cell surface through a variety of mechanisms such as van der Waals attraction and electrostatic interactions, and forms a layer of nonspecifically adsorbed ions and molecules on the cell surface. Thus, the bacterial cell surface charge comprised the contribution from the cell wall as well as layers of nonspecifically adsorbed ions and molecules on the cell surface. This is the cell surface charge perceived by other bacterial cells in the growth medium. Given that different growth medium comprises different ensemble of proteins and metabolites that could adsorb onto the cell surface of bacteria, it is important to examine the effect of growth in different medium on the cell surface characteristics of bacterial cells using zeta potential as the proxy parameter. Defined at the shear plane, zeta potential provides a comprehensive view of the cell surface charge that include the nonspecifically adsorbed ions and molecules on the cell surface and the intrinsic electric charges in the cell wall. Using Escherichia coli DH5α (ATCC 53868) as model organism, experiments performed with deionized water as wash and resuspension buffer revealed that the zeta potential-pH profiles of cells grown in LB Lennox, and LB Lennox with 2 g/L glucose overlapped each other over the entire pH range from 2 to 9. This suggested that there was little physiological adaptation of the cell envelope of cells grown in LB Lennox supplemented with 2 g/L glucose, which indicated that the medium could be used for increasing biomass yield without affecting cell surface characteristics. Similarly, the zeta potential-pH profiles of E. coli DH5α grown in LB Lennox and LB Lennox buffered with 89 mM potassium hydrogen phosphate buffer also overlapped each other, which highlighted that the buffered medium did not elicit physiological adaptation of the cell envelope. However, supplementation of the LB Lennox (buffered) medium with 6 g/L glucose resulted in a more negatively charged zeta potential-pH profile in the pH range from 4 to 12 compared to that during growth in LB Lennox. Growth of E. coli DH5α in other media such as Tryptic Soy Broth (TSB), formulated medium, and formulated medium with 6 g/L glucose also resulted in more negatively charged zeta potential-pH profiles compared to that during growth in LB Lennox medium. However, the point-of-zero-charge (pHzpc) of cells grown in TSB and formulated medium were the same as that of cells grown in LB Lennox medium. Collectively, physiological adaptation to growth in different media as well as different ensemble of proteins and metabolites nonspecifically adsorbed to the cell surface would generally result in different zeta potential-pH profiles of bacteria cultivated in growth media of different compositions. Understanding the cell surface charge characteristics of E. coli DH5α grown in different media would thus help unveil the mysteries of cell-cell interactions in the medium.


2018 ◽  
Author(s):  
Wenfa Ng

Proteins and metabolites typically adsorb to bacterial cell surface through a variety of mechanisms such as van der Waals attraction and electrostatic interactions, and forms a layer of nonspecifically adsorbed ions and molecules on the cell surface. Thus, the bacterial cell surface charge comprised the contribution from the cell wall as well as layers of nonspecifically adsorbed ions and molecules on the cell surface. This is the cell surface charge perceived by other bacterial cells in the growth medium. Given that different growth medium comprises different ensemble of proteins and metabolites that could adsorb onto the cell surface of bacteria, it is important to examine the effect of growth in different medium on the cell surface characteristics of bacterial cells using zeta potential as the proxy parameter. Defined at the shear plane, zeta potential provides a comprehensive view of the cell surface charge that include the nonspecifically adsorbed ions and molecules on the cell surface and the intrinsic electric charges in the cell wall. Using Escherichia coli DH5α (ATCC 53868) as model organism, experiments performed with deionized water as wash and resuspension buffer revealed that the zeta potential-pH profiles of cells grown in LB Lennox, and LB Lennox with 2 g/L glucose overlapped each other over the entire pH range from 2 to 9. This suggested that there was little physiological adaptation of the cell envelope of cells grown in LB Lennox supplemented with 2 g/L glucose, which indicated that the medium could be used for increasing biomass yield without affecting cell surface characteristics. Similarly, the zeta potential-pH profiles of E. coli DH5α grown in LB Lennox and LB Lennox buffered with 89 mM potassium hydrogen phosphate buffer also overlapped each other, which highlighted that the buffered medium did not elicit physiological adaptation of the cell envelope. However, supplementation of the LB Lennox (buffered) medium with 6 g/L glucose resulted in a more negatively charged zeta potential-pH profile in the pH range from 4 to 12 compared to that during growth in LB Lennox. Growth of E. coli DH5α in other media such as Tryptic Soy Broth (TSB), formulated medium, and formulated medium with 6 g/L glucose also resulted in more negatively charged zeta potential-pH profiles compared to that during growth in LB Lennox medium. However, the point-of-zero-charge (pHzpc) of cells grown in TSB and formulated medium were the same as that of cells grown in LB Lennox medium. Collectively, physiological adaptation to growth in different media as well as different ensemble of proteins and metabolites nonspecifically adsorbed to the cell surface would generally result in different zeta potential-pH profiles of bacteria cultivated in growth media of different compositions. Understanding the cell surface charge characteristics of E. coli DH5α grown in different media would thus help unveil the mysteries of cell-cell interactions in the medium.


2001 ◽  
Vol 43 (3) ◽  
pp. 153-164 ◽  
Author(s):  
W.William Wilson ◽  
Mary Margaret Wade ◽  
Steven C. Holman ◽  
Franklin R. Champlin

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1519
Author(s):  
Leixin Ouyang ◽  
Rubia Shaik ◽  
Ruiting Xu ◽  
Ge Zhang ◽  
Jiang Zhe

Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle (NP) interactions. Fluorescent nanoparticles (NPs) were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescent light intensity and number of nanoparticles, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, human umbilical vein endothelial cells (HUVECs) and HeLa cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potentials of the two types of cells were obtained, which are in good agreement with the standard electrophoretic light scattering measurement. This method can be used for rapid surface charge mapping of single particles or cells, and can advance cell-surface-charge characterization applications in many biomedical fields.


2016 ◽  
Vol 83 ◽  
pp. 548-558 ◽  
Author(s):  
Debasis Mandal ◽  
Sandeep Kumar Dash ◽  
Balaram Das ◽  
Sourav Chattopadhyay ◽  
Totan Ghosh ◽  
...  

Chemosphere ◽  
1980 ◽  
Vol 9 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Christopher L. Haber ◽  
Thomas G. Tornabene ◽  
R.K. Skogerboe

2006 ◽  
Vol 69 (8) ◽  
pp. 1835-1843 ◽  
Author(s):  
DIKE O. UKUKU ◽  
WILLIAM F. FETT

Adherence of bacteria to cantaloupe rind is favored by surface irregularities such as roughness, crevices, and pits, thus reducing the ability of washing or sanitizer treatments to remove or inactivate attached cells. In this study, we compared the surface charge and hydrophobicity of two cantaloupe-related outbreak strains of Salmonella Poona (RM2350 and G-91-1595) to those of 14 additional Salmonella strains using electrostatic and hydrophobic interaction chromatography. The relative abilities of the 16 strains to attach to cantaloupe surfaces and resist removal by washing with water, chlorine (200 ppm), or hydrogen peroxide (2.5%) for 5 min after a storage period of up to 7 days at 5 to 20°C also were determined. Whole cantaloupes were inoculated with each pathogen at 8.36 log CFU/ml, dried for 1 h inside a biosafety cabinet, stored, and then subjected to the washing treatments. Only the positive surface charge of the two cantaloupe-related strains of Salmonella Poona was significantly higher (P < 0.05) than that of the other strains. Initial bacterial attachment to cantaloupe surfaces ranged from 3.68 to 4.56 log CFU/cm2 (highest values for Salmonella Michigan, Newport, Oranienburg, and Mbandaka). The average percentage of the total bacterial population strongly attached to the cantaloupe surface for the Salmonella serovars studied ranged from 0.893 to 0.946 at 5°C and from 0.987 to 0.999 at 25°C. Washing inoculated melons with water did not produce a significant reduction in the concentration of the pathogens (P > 0.05). Chlorine and hydrogen peroxide treatments caused an average 3-log reduction when applied 20 to 40 min postinoculation. However, sanitizer treatments applied 60 min or more postinoculation were less effective (approximately 2.5-log reduction). No significant differences were noted in sanitizer efficacy against the individual strains (P > 0.05). The two cantaloupe-related outbreak Salmonella Poona strains did not significantly differ from the other Salmonella strains tested in negative cell surface charge or hydrophobicity, were not more effective in attaching to whole melon surfaces, and were not more resistant to the various washing treatments when present on rinds.


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