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Miranda Mercado DA, Godoy Alarcón EV, V-Niño ED. Time evolution of electrical impedance spectra of Staphylococcus aureus and Escherichia coli bacteria. Bioelectrochemistry 2024; 155:108557. [PMID: 37708781 DOI: 10.1016/j.bioelechem.2023.108557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/16/2023]
Abstract
This research work reports the time evolution of the electrical properties of gram-positive and gram-negative bacteria in aqueous suspensions with methyl violet and Lugol; measurements of galvanostatic electrical impedance spectra were made in a frequency range of 10Hz to 100kHz. The magnitude of the impedance as a function of frequency for methicillin-resistant strains, Staphylococcus aureus (gram-positive), and Escherichia coli O157: H7 (gram-negative) in the presence of methyl violet and Lugol, showed that both strains exhibited a progressive decrease in the magnitude of the electrical impedance with an increasing bacterial population; however, the variation in the magnitude rate of the impedance over time is completely different between the gram-positive and gram-negative strains. The results suggest that the time evolution of the electrical impedance spectra can be used to differentiate Staphylococcus aureus from Escherichia coli bacteria.
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Affiliation(s)
| | - Erika Viviana Godoy Alarcón
- Instituto de Química, Universidade Estadual Paulista, Rua Prof. Francisco Degni, 55, Araraquara 14800-060, São Paulo, Brazil
| | - Ely Dannier V-Niño
- Escuela de Física, Universidad Industrial de Santander, Carrera 27, Calle 9, Bucaramanga 680002, Santander, Colombia
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2
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Rozaini AZA, Abdulhameed A, Deivasigamani R, Nadzreen N, Zin NM, Kayani AA, Buyong MR. Dielectrophoresis microbial characterization and isolation of Staphylococcus aureus based on optimum crossover frequency. Electrophoresis 2023; 44:1220-1233. [PMID: 37259263 DOI: 10.1002/elps.202200276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 04/19/2023] [Accepted: 04/29/2023] [Indexed: 06/02/2023]
Abstract
Characterization of antibiotic-resistant bacteria is a significant concern that persists for the rapid classification and analysis of the bacteria. A technology that utilizes the manipulation of antibiotic-resistant bacteria is key to solving the significant threat of these pathogenic bacteria by rapid characterization profile. Dielectrophoresis (DEP) can differentiate between antibiotic-resistant and susceptible bacteria based on their physical structure and polarization properties. In this work, the DEP response of two Gram-positive bacteria, namely, Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible S. aureus (MSSA), was investigated and simulated. The DEP characterization was experimentally observed on the bacteria influenced by oxacillin and vancomycin antibiotics. MSSA control without antibiotics has crossover frequencies (f x 0 ${f_{x0}}$ ) from 6 to 8 MHz, whereas MRSA control is from 2 to 3 MHz. Thef x 0 ${f_{x0}}$ changed when bacteria were exposed to the antibiotic. As for MSSA, thef x 0 ${f_{x0}}$ decreased to 3.35 MHz compared tof x 0 ${f_{x0}}$ MSSA control without antibiotics, MRSA,f x 0 ${f_{x0}}$ increased to 7 MHz when compared to MRSA control. The changes in the DEP response of MSSA and MRSA with and without antibiotics were theoretically proven using MyDEP and COMSOL simulation and experimentally based on the modification to the bacteria cell walls. Thus, the DEP response can be employed as a label-free detectable method to sense and differentiate between resistant and susceptible strains with different antibiotic profiles. The developed method can be implemented on a single platform to analyze and identify bacteria for rapid, scalable, and accurate characterization.
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Affiliation(s)
- Arash Zulkarnain Ahmad Rozaini
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Abdullah Abdulhameed
- Center for Communication Systems and Sensing, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
| | - Revathy Deivasigamani
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Nurulhuda Nadzreen
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Noraziah Mohamad Zin
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Amin Ahmad Kayani
- Functional Materials and Microsystems Research Group and the Micro Nano Research Facility, RMIT University, Melbourne, Australia
- ARC Research Hub for Connected Sensors for Health, RMIT University, Melbourne, Australia
| | - Muhamad Ramdzan Buyong
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
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A van der Waals force-based adhesion study of stem cells exposed to cold atmospheric plasma jets. Sci Rep 2022; 12:12069. [PMID: 35840616 PMCID: PMC9287354 DOI: 10.1038/s41598-022-16277-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/07/2022] [Indexed: 11/20/2022] Open
Abstract
Cold atmospheric plasma has established its effect on cell adhesion. Given the importance of cell adhesion in stem cells, the current study investigates the effect of plasma treatment on Human Bone Marrow Mesenchymal Stem Cells (HBMMSCs) adhesion by which the differentiation and fate of cells are determined. In this paper, adhesion modification is considered not only for cell- ECM (Extra cellular Matrix), but also between suspended cells, and enhanced adhesions were found in both circumstances. Regarding the previous works, the increase of the cell–ECM adhesion during the plasma therapy was mostly attributed to the enhancement of the production and activity of integrin proteins. Nevertheless, considering the importance of van der Waals forces at the cellular level, the effect of cold plasma on VDWFs and so its effect on adhesion is investigated in this work for the first time, to the best of our knowledge. For this purpose, employing the semi-empirical methods, the role of the plasma therapy on the VDWF between the cells has been studied at three levels; (a) plasma-induced dipole formation, (b) Hammaker coefficient modification of culture medium, and c) cell roughness modification. For suspended cell condition, we conclude and support that van der Waals forces (VDWFs) enhancement has a key role in cell adhesion processes. We believe that, the present work gives a new physical insight in studying the plasma therapy method at the cellular level.
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Fernandez RE, Rohani A, Farmehini V, Swami NS. Review: Microbial analysis in dielectrophoretic microfluidic systems. Anal Chim Acta 2017; 966:11-33. [PMID: 28372723 PMCID: PMC5424535 DOI: 10.1016/j.aca.2017.02.024] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 02/03/2017] [Accepted: 02/20/2017] [Indexed: 12/13/2022]
Abstract
Infections caused by various known and emerging pathogenic microorganisms, including antibiotic-resistant strains, are a major threat to global health and well-being. This highlights the urgent need for detection systems for microbial identification, quantification and characterization towards assessing infections, prescribing therapies and understanding the dynamic cellular modifications. Current state-of-the-art microbial detection systems exhibit a trade-off between sensitivity and assay time, which could be alleviated by selective and label-free microbial capture onto the sensor surface from dilute samples. AC electrokinetic methods, such as dielectrophoresis, enable frequency-selective capture of viable microbial cells and spores due to polarization based on their distinguishing size, shape and sub-cellular compositional characteristics, for downstream coupling to various detection modalities. Following elucidation of the polarization mechanisms that distinguish bacterial cells from each other, as well as from mammalian cells, this review compares the microfluidic platforms for dielectrophoretic manipulation of microbials and their coupling to various detection modalities, including immuno-capture, impedance measurement, Raman spectroscopy and nucleic acid amplification methods, as well as for phenotypic assessment of microbial viability and antibiotic susceptibility. Based on the urgent need within point-of-care diagnostics towards reducing assay times and enhancing capture of the target organism, as well as the emerging interest in isolating intact microbials based on their phenotype and subcellular features, we envision widespread adoption of these label-free and selective electrokinetic techniques.
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Affiliation(s)
- Renny E Fernandez
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904, USA
| | - Ali Rohani
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904, USA
| | - Vahid Farmehini
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904, USA
| | - Nathan S Swami
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904, USA.
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Ward BK, Dufault RJ, Hassell R, Cutulle MA. Upscaled Bioammonium/Ammonia Production by Clostridium Aminophilum Cultured with Soy Protein Isolate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:2930-2935. [PMID: 28317381 DOI: 10.1021/acs.jafc.7b00113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The goal of this study was to scale up the production of bioammonium/ammonia (BAA) by Clostridium aminophilum from test tube size small batches of 1.0 g of soy protein isolate (SPI) with 10 mL of salt solution to the lab scale bioreactor level of 1.8 kg·18 L-1 salt solution in amounts required for precision fertigation in field trials. An 18 L bioreactor was designed and constructed similar to commercially available lab scale bioreactors. Novel methods were implemented to maintain sterility and anaerobic conditions throughout the preparation and operation of the bioreactor. C. aminophilum was cultured at rates of 1.8 kg·18 L-1 salt solution, ultimately producing a BAA mean concentration of 82.9 mM, which was 34% greater than the amount achieved in the test tubes of 61.7 mM.
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Affiliation(s)
- Brian K Ward
- Department of Plant and Environmental Sciences, Horticulture, Clemson Coastal Research and Education Center, Clemson University , Charleston, South Carolina 29414, United States
| | - Robert J Dufault
- Department of Plant and Environmental Sciences, Horticulture, Clemson Coastal Research and Education Center, Clemson University , Charleston, South Carolina 29414, United States
| | - Richard Hassell
- Department of Plant and Environmental Sciences, Horticulture, Clemson Coastal Research and Education Center, Clemson University , Charleston, South Carolina 29414, United States
| | - Matthew A Cutulle
- Department of Plant and Environmental Sciences, Horticulture, Clemson Coastal Research and Education Center, Clemson University , Charleston, South Carolina 29414, United States
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Babadi AA, Bagheri S, Hamid SB. Progress on implantable biofuel cell: Nano-carbon functionalization for enzyme immobilization enhancement. Biosens Bioelectron 2016; 79:850-60. [DOI: 10.1016/j.bios.2016.01.016] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 01/25/2023]
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8
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Low-frequency dielectric dispersion of bacterial cell suspensions. Colloids Surf B Biointerfaces 2014; 119:1-5. [DOI: 10.1016/j.colsurfb.2014.04.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 03/26/2014] [Accepted: 04/23/2014] [Indexed: 11/23/2022]
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9
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Vahey MD, Voldman J. High-throughput cell and particle characterization using isodielectric separation. Anal Chem 2009; 81:2446-55. [PMID: 19253950 PMCID: PMC2675787 DOI: 10.1021/ac8019575] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Separations can be broadly categorized as preparative, where the objective is to extract purified quantities of a sample from a complex mixture, or analytic, where the goal is to determine and quantify the contents of the original mixture. Here we demonstrate the application of a new microfluidic separation method, isodielectric separation (IDS), to a range of analytic separations involving cells and particles spanning several orders of magnitude in volume and electrical conductivity. In IDS, cells are dielectrophoretically concentrated to the region along an electrical conductivity gradient where their polarizability vanishes; by measuring this position--the isodielectric point (IDP)--as operating conditions such as the frequency and voltage of the applied electric field are varied, we are able to sort cells or particles with distinct IDPs while simultaneously characterizing their electrical properties. We apply this technique to measure the electrical properties of polystyrene microspheres, viable and nonviable cells of the budding yeast Saccharomyces cerevisiae , and murine pro B cells, including how these electrical properties vary with the electrical conductivity of the surrounding solvent.
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Affiliation(s)
- M. D. Vahey
- Department of Electrical Engineering and Computer Science, 77 Massachusetts Avenue, Building 36-824, Cambridge, Massachusetts 02139
| | - J. Voldman
- Department of Electrical Engineering and Computer Science, 77 Massachusetts Avenue, Building 36-824, Cambridge, Massachusetts 02139
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Zhivkov A, Gyurova A. High frequency electric polarizability of bacteria E. coli: Dependence on the medium ionic strength. Colloids Surf B Biointerfaces 2008; 66:201-5. [DOI: 10.1016/j.colsurfb.2008.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 06/13/2008] [Accepted: 06/13/2008] [Indexed: 10/21/2022]
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Johari J, Hübner Y, Hull JC, Dale JW, Hughes MP. Dielectrophoretic assay of bacterial resistance to antibiotics. Phys Med Biol 2003; 48:N193-8. [PMID: 12894983 DOI: 10.1088/0031-9155/48/14/401] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics.
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Affiliation(s)
- Juliana Johari
- School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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12
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Yunus Z, Mason V, Verduzco-Luque CE, Markx GH. A simple method for the measurement of bacterial particle conductivities. J Microbiol Methods 2002; 51:401-6. [PMID: 12223301 DOI: 10.1016/s0167-7012(02)00129-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A method was developed for the measurement of the bacterial particle conductivity, based on the measurement of the conductivity of a bacterial cell suspension sigma(s) and the suspending medium sigma(m). A line plotted through sigma(s) - sigma(m) versus sigma(m) crosses the x-axis at sigma(m) = sigma(p), independent of the bacterial cell concentration. The method does not require anything more complex than a centrifuge and a conductivity meter. Knowledge of the bacterial particle conductivity is of importance in, for example, the dielectrophoretic separation, manipulation and trapping of bacterial cells, as well as the study of their physiological state.
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Affiliation(s)
- Zalini Yunus
- Department of Chemical Engineering, UMIST, PO Box 88, Sackville Street, Manchester M60 1QD, UK
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13
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The dielectric properties of biological cells at radiofrequencies: applications in biotechnology. Enzyme Microb Technol 1999. [DOI: 10.1016/s0141-0229(99)00008-3] [Citation(s) in RCA: 241] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Brown AP, Betts WB, Harrison AB, O'Neill JG. Evaluation of a dielectrophoretic bacterial counting technique. Biosens Bioelectron 1999; 14:341-51. [PMID: 10230035 DOI: 10.1016/s0956-5663(99)00002-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Dielectrophoresis, an electrokinetic migration of particles, can occur in non-uniform alternating electric fields and is dependent upon the dielectric nature of the cells and their suspending medium. An enumeration system utilising this phenomenon is described, which has the potential to count particles selectively, including different bacterial or eukaryotic cell species and even sub-populations of different cell viability states or sizes. Relationships were observed between suspension concentrations and the extent of dielectrophoretic (DEP) collection for polystyrene latex beads, pure bacterial samples and mixtures of bacterial species including Escherichia coli, Serratia marcescens, Pseudomonas aeruginosa and Bacillus subtilis. A similar relationship was utilised for polystyrene latex as a calibration line to enable the concentration of particles in a suspension to be determined according to the level of DEP collection. The particle concentration of an unknown test sample was found to lie within the predicted concentration range determined on the basis of DEP collection. In addition, the predicted limits were found only to deviate between -6.2 and +6.9% from the mean particle concentration.
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Affiliation(s)
- A P Brown
- Department of Biology, University of York, UK
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van der Wal A, Norde W, Zehnder AJ, Lyklema J. Determination of the total charge in the cell walls of Gram-positive bacteria. Colloids Surf B Biointerfaces 1997. [DOI: 10.1016/s0927-7765(96)01340-9] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Arnold WM, Schmutzler RK, Schmutzler AG, van der Ven H, Al-Hasani S, Krebs D, Zimmermann U. Electro-rotation of mouse oocytes: single-cell measurements of zona-intact and zona-free cells and of the isolated zona pellucida. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 905:454-64. [PMID: 3689789 DOI: 10.1016/0005-2736(87)90475-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Passive electrical properties of oocytes and of zonae pellucidae, and the mechanical coupling between them, can be elucidated by means of rotating-field-induced rotation. In low-conductivity media (25-100 microS/cm) rotation of mouse oocytes (with or without their zonae) requires fields in the 1-100 kHz frequency range. However, an isolated zona shows weak rotation in the opposite direction to that of a cell, and in response to much higher field frequencies (approx. 1 MHz). In zona-intact mouse oocytes, the rotation of cell and zona are not rigidly coupled: thus rotation of the cell can still be induced when the zona is held stationary. However, rotation of freely suspended zona-intact cells is much slower than that of zona-free cells and requires an optimum field frequency that is approximately 1.5 kHz higher. These observations show that the electrical properties of the oocyte that are measured by rotation are altered by the presence of the zona pellucida, even though no such influence has been detected using micro-electrodes. The data are consistent with the zona acting as a porous shell with a conductivity of 40 microS/cm (preliminary estimate made at a single medium conductivity of 26 microS/cm). Measurements on cells from which the zonae had been removed gave values for the membrane capacity and resistivity of 1.2-1.3 microF/cm2 and 400 omega.cm2, respectively. These values may reflect the presence of plasmalemma microvilli. The results strongly suggest that the technique may be useful for studies of cell maturation and for in vitro fertilization, because the cells may be further cultured after measurement.
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Affiliation(s)
- W M Arnold
- Lehrstuhl für Biotechnologie der Universität Würzburg, F.R.G
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Geier BM, Wendt B, Arnold WM, Zimmermann U. The effect of mercuric salts on the electro-rotation of yeast cells and comparison with a theoretical model. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 900:45-55. [PMID: 3297146 DOI: 10.1016/0005-2736(87)90276-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The rotational spectrum of yeast cells changed after pre-treatment of the cells with HgCl2 or Hg(NO3)2 and became indistinguishable from that of ultrasonically produced cell walls. The spectrum of the affected cells contained a peak which could only be explained by attributing a conductivity to the cell walls that was higher than that of the medium. Theoretical models of the rotational response are fully in accord with the experimental spectra. It is shown that the rotation method is capable of measuring even the low cell wall conductivity of yeast cells (which was found to be 33 microS/cm at 10 microS/cm medium conductivity). Knowledge of the spectra allowed a field frequency to be selected at which untreated cells showed no rotation, but at which cells affected by treatment with Hg(II) identified themselves by rotating in the same direction as the field. Calculation of the percentage of cells showing this co-field rotation gave an index (termed the co-field rotation value) of the proportion of the cells that were affected. Using this technique, effects of 25 nmol/l Hg(II) could be demonstrated. In media of low conductivity (10 microS/cm) the change in the rotational spectrum was usually 'all-or-none', whereas at 200 microS/cm a graded Hg(II)-mediated change became apparent. The co-field rotation method showed that the action of small quantities of Hg(II) was still increasing after 3 h of incubation and paralleled the Hg(II)-induced K+ release. A rapid reduction of the effects of Hg(II) was seen when 3-30 mM K+ (or Na+) or when 1 mM Ca2+ were present in the incubation medium, or as the pH was increased. At high incubation cell concentrations the toxic effect of Hg(II) was reduced, apparently due to binding by the cells.
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Morgan H, Ginzburg M, Ginzburg B. Dielectric properties of the halophilic bacteria Halobacterium halobium and H. marismortui with reference to the conductivities and permittivities of the cytoplasmic membrane and intracellular phases. Biochim Biophys Acta Gen Subj 1987. [DOI: 10.1016/0304-4165(87)90070-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Arnold W, Geier BM, Wendt B, Zimmermann U. The change in the electro-rotation of yeast cells effected by silver ions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 1986. [DOI: 10.1016/0167-4889(86)90006-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Cerbón J, Ontiveros C, Janovitz A. Phosphoinositides provide a regulatory mechanism of surface charge and active transport. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 887:275-82. [PMID: 3015237 DOI: 10.1016/0167-4889(86)90155-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Yeast cells, when grown in the presence of arsenate, are capable of accumulating phosphoinositides (PI) at the expense of inhibiting their degradation more than their synthesis. PI levels return to normal when the cells are cultured or exposed to media without arsenate. These reversible changes are employed as a tool to test the effect of inositide accumulation and dynamics on several membrane properties. In the PI-rich cells, phosphate and arsenate transport from low external concentrations (high affinity systems), as well as the transport of glycine, which enter the cells accompanied by protons, were increased. The proton ejection energized by glucose is also enhanced in the PI-rich cells that show a more efficient potassium inflow at pH 4.0-4.5. The membrane surface potential of the PI-rich cells was found to be 2-times higher than that of the normal cells, in agreement with the 2-fold increment in the PI. All the above mentioned alterations in membrane properties are reverted when the PI content of the PI-rich cells is reduced to the level of normal cells. The results show the participation of the phosphoinositides in the formation, maintenance and regulation of the membrane surface potential and their possible influence upon transport mechanisms.
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Thwaites JJ, Mendelson NH. Biomechanics of bacterial walls: studies of bacterial thread made from Bacillus subtilis. Proc Natl Acad Sci U S A 1985; 82:2163-7. [PMID: 3920662 PMCID: PMC397513 DOI: 10.1073/pnas.82.7.2163] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bacterial threads of up to 1 m in length have been produced from filaments of separation-suppressed mutants of Bacillus subtilis. Individual threads may contain 20,000 cellular filaments in parallel alignment. The tensile properties of bacterial threads have been examined by using conventional textile engineering techniques. The kinetics of elongation at constant load are indicative of a viscoelastic material. Both Young's modulus and breaking stress are highly dependent upon relative humidity. By extrapolation to 100% relative humidity, it appears that cell walls may be able to bear only internal osmotic pressures of about 2 atmospheres (2.03 X 105(5) Pa) in living cells. Similarly, the strength of wall material limits the amount of cell-surface charge permissible to only a small fraction of that known to be carried by the negatively charged wall polymers.
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23
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Lang W, Archibald A. Length of teichoic acid chains incorporated into walls ofBacillus subtilisgrown under conditions of differing phosphate supply. FEMS Microbiol Lett 1982. [DOI: 10.1111/j.1574-6968.1982.tb08234.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Doyle RJ, Matthews TH, Streips UN. Chemical basis for selectivity of metal ions by the Bacillus subtilis cell wall. J Bacteriol 1980; 143:471-80. [PMID: 6772632 PMCID: PMC294273 DOI: 10.1128/jb.143.1.471-480.1980] [Citation(s) in RCA: 128] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The use of equilibrium dialysis techniques established that isolated cell walls of Bacillus subtilis possess selective affinities for several cations. The binding of these cations to the cell wall was influenced by the presence of various functional groups in the peptidoglycan matrix. Selective chemical modification of the free carboxyl and amino groups showed that when amino groups were replaced by neutral, bulky, or negatively charged groups, the sites available for cation complexing generally increased. Introduction of positive charges into the wall resulted in a marked decrease in the numbers of metal binding sites and usually a decrease in the apparent association constants. Both teichoic acid and peptidoglycan contribute to the sites available for interaction with metals. Hill plots of equilibrium dialysis data suggest that metal binding to cell walls involves negative cooperativity. Competition between various metals for binding sites suggested that the cations complex with identical sites on the cell walls. When the hydrogen ion concentration was increased, the affinity of the walls for metals decreased, but the numbers of metal binding sites remained constant, suggesting that cations and protons also compete for the same sites.
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25
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Zimmermann U, Groves M, Schnabl H, Pilwat G. Development of a new coulter counter system: Measurement of the volume, internal conductivity, and dielectric breakdown voltage of a single guard cell protoplast ofVicia faba. J Membr Biol 1980. [DOI: 10.1007/bf01869004] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Ginzburg M, Lepkipfer B, Porath A, Ginzburg BZ. Passive electrical properties of Halobacterium species. I. Low-frequency range. BIOPHYSICS OF STRUCTURE AND MECHANISM 1978; 4:237-49. [PMID: 687774 DOI: 10.1007/bf02426088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The electrical conductivity of suspensions of two species of Halobacterium was measured at low A. C. frequency. The results obtained from Halobacterium halobium suspensions show that the bacteria act as non-conducting particles. In contrast, the cells of a Halobacterium obtained from the Dead Sea (Halobacterium marismortui) had an apparently high conductivity which can be explained partly in terms of the cell-membrane being pierced by pores through which ions can move freely and partly in terms of highly concentrated cell ions, all of which are mobile.
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Burdett ID, Higgins ML. Study of pole assembly in Bacillus subtilis by computer reconstruction of septal growth zones seen in central, longitudinal thin sections of cells. J Bacteriol 1978; 133:959-71. [PMID: 415053 PMCID: PMC222109 DOI: 10.1128/jb.133.2.959-971.1978] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The septal growth of Bacillus subtilis 168/s has been studied by making a number of observations from thin sections of cells from exponentially growing cultures. The process was initiated by the formation of a new cross wall under a preexisting layer of cylindrical wall. An annular notch appeared to cut through the overlying wall and presumably allowed the cross wall to split into two layers of peripheral wall. During this initial notching process, two raised bands of wall material were produced which resembled those previously observed in morphological studies of Streptococcus faecalis. Through an improved fixation technique, it was possible to preserve the bands seen in B. subtilis to the extent that they were used as markers to study the subsequent stages of septal growth. These stages included (i) the continued displacement of the two bands from the cross wall (as the two nascent polar surfaces enlarged and as the diameter of the cross wall decreased), (ii) the closure of the cross wall, and (iii) the final severance of the common cross wall connection between two completed poles. To study this process in a more quantitative manner, three-dimensional reconstructions of the envelope observed between pairs of the raised bands were made from axial thin sections of cells. The process of reconstruction was based on a technique by which x, y coordinates were taken from thin sections and were rotated around the cell's central axis. These reconstructions were used to estimate the surface area or volume of the reconstructed zones or their parts. A round of septal growth was then simulated by arranging 118 reconstructions in order of increasing surface area or volume. The topology of the process was studied by noting how various measurements of septal thickness, length, surface area, and volume varied as a function of increasing septal zone size. This analysis was based on several assumptions, of which three of the most important are: (i) the bands produced by the initial notching process are markers which separate septal from cylindrical wall growth; (ii) a septal zone observed between pairs of bands is made up of two nascent poles and a single cross wall; and (iii) as septal zones develop in terms of relative age they increase in size (volume or surface area) or amount of wall. The data suggested that the S. faecalis model of surface growth (in which polar growth occurs through a regulated constrictive separation and expansion of a cross wall) also seems applicable to the pattern of septal growth observed here for B. subtilis. This was indicated from measurements which showed that increases in the size of nascent polar surfaces were correlated with decreases in cross wall diameter. An explanation of these observations may be that decreases in cross wall diameter were due to a progressive splitting of the cross wall that removed surface from the outer circumference of the cross wall and converted it into new polar surface. Calculations further suggested that if the poles of B. subtilis were made by this model a sizeable and variable increase in surface area of the cross wall would also be required to convert these separating cross wall layers into two curved polar structures. Measurements of wall thickness taken from various locations within septal zones indicated that while the thickness of the polar wall of B. subtilis was constant over its surface, the width of the cross wall varied considerably during a round of synthesis. Again, one of the simplest explanations compatible with these observations and those previously made in S. faecalis is that the B. subtilis cross wall is brought to a constant thickness (possibly by remodeling or precursor addition) before or during separation. Although most observations made from the reconstruction of the septal zones of B. subtilis may fit the S. faecalis model of surface growth, differences in the pattern of septal growth were seen when the two organisms were compared. These have been discussed in terms of differences in the regulation of their respective septal growth sites and basic mechanisms of wall assembly and modification.
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Tsien HC, Shockman GD, Higgins ML. Structural arrangement of polymers within the wall of Streptococcus faecalis. J Bacteriol 1978; 133:372-86. [PMID: 412837 PMCID: PMC222016 DOI: 10.1128/jb.133.1.372-386.1978] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The structure of the cell wall of Streptococcus faecalis was studied in thin sections and freeze fractures of whole cells and partially purified wall fractions. Also, the structures of wall preparations treated with hot trichloroacetic acid to remove non-peptidoglycan wall polymers were compared with wall preparations that possess a full complement of accessory polymers. The appearance of the wall varied with the degree of hydration of preparations and physical removal of the cell membrane from the wall before study. Seen in freeze fractures of whole cells, the fully hydrated wall seemed to be a thick, largely amorphic layer. Breaking cells with beads caused the cell membrane to separate from the wall and transformed the wall from a predominantly amorphic layer to a structure seemingly made up of two rows of "cobblestones" enclosing a central channel of lower density. Dehydration of walls seemingly caused the cobblestones to be transformed into two bands which continued to be separated by a channel. This channel was also observed in isolated wall preparations treated with hot trichloroacetic acid to remove non-peptidoglycan polymers. These observations are consistent with the interpretation that both peptidogylcan and non-peptidoglycan polymers are concentrated at the outer and inner surfaces of cell walls. These observations are discussed in relation to possible models of wall structure and assembly.
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Abstract
Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid model.
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Neihof R, Echols WH. Physicochemical studies of microbial cell walls. I. Comparative electrophoretic behavior of intact cells and isolated cell walls. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 318:23-32. [PMID: 4201060 DOI: 10.1016/0005-2736(73)90332-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Marquis RE, Carstensen EL. Electric conductivity and internal osmolality of intact bacterial cells. J Bacteriol 1973; 113:1198-206. [PMID: 4632395 PMCID: PMC251682 DOI: 10.1128/jb.113.3.1198-1206.1973] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Intact cells of Streptococcus faecalis and Micrococcus lysodeikticus were found to have high-frequency electric conductivities of 0.90 and 0.68 mho/m, respectively. These measured values, which reflect movements of ions both within the cytoplasm and within the cell wall space, were only about one-third of those calculated on the basis of determinations of the amounts and types of small ions within the cells. Concentrated suspensions of bacteria with damaged membranes showed similarly large disparities between measured and predicted conductivities, whereas the conductivities of diluted suspensions were about equal to predicted values. Thus, the low mobilities of intracellular ions appeared to be interpretable in terms of the physicochemical behavior of electrolytes in concentrated mixtures of small ions and cell polymers. In contrast to the low measured values for conductivity of intact bacteria, values for intracellular osmolality measured by means of a quantitative plasmolysis technique were higher than expected. For example, the plasmolysis threshold for S. faecalis cells indicated an internal osmolality of about 1.0 osmol/kg, compared with a value of only 0.81 osmol/liter of cell water calculated from a knowledge of the cell content and the distribution of small solutes. In all, our results indicate that most of the small ions within vegetative bacterial cells are free to move in an electric field and that they contribute to cytoplasmic osmolality.
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Carstensen EL, Aldridge WG, Child SZ, Sullivan P, Brown HH. Stability of cells fixed with glutaraldehyde and acrolein. J Cell Biol 1971; 50:529-32. [PMID: 4939525 PMCID: PMC2108264 DOI: 10.1083/jcb.50.2.529] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Carstensen EL, Marquis RE, Gerhardt P. Dielectric study of the physical state of electrolytes and water within Bacillus cereus spores. J Bacteriol 1971; 107:106-13. [PMID: 4998245 PMCID: PMC246892 DOI: 10.1128/jb.107.1.106-113.1971] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Dielectric measurements revealed that dormant spores of Bacillus cereus have extremely low conductivities at high frequencies (50 MHz) and so must contain remarkably low concentrations of mobile ions both within the core and in the surrounding integuments. Activation, germination, and outgrowth were all accompanied by increases in conductivity of the cells and their suspending medium, and this result indicated that intracellular electrolytes had become ionized and leaked from the spores. High-frequency dielectric constants of spores were consistent with normal states for cell water. These values increased during successive stages of development from dormant spore to vegetative bacillus, and they could be directly related to increases in cell water content. In all, the results refuted a model of the dormant spore involving freely mobile, ionized electrolytes and supported a model involving electrostatically bound electrolytes.
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Carstensen EL, Maniloff J, Einolf CW. Electrical properties and ultrastructure of Mycoplasma membranes. Biophys J 1971; 11:572-81. [PMID: 5089915 PMCID: PMC1483982 DOI: 10.1016/s0006-3495(71)86236-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Mycoplasma, in particular species laidlawii and gallisepticum, are found to have a very small, low frequency conductivity as would be predicted by the dielectric model for bacteria and their apparent lack of cell wall structure. Membrane capacitance values for the two organisms are both about 0.9 muF/cm(2), although electron micrographs show that the membrane of M. gallisepticum is 20-40 A thicker than that of M. laidlawii.
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Abstract
Isolated cell walls of Staphylococcus aureus and Micrococcus lysodeikticus were found to expand and contract in response to changes in environmental pH and ionic strength. These volume changes, which could amount to as much as a doubling of wall dextran-impermeable volume, were related to changes in electrostatic interactions among fixed, ionized groups in wall polymers, including peptidoglycans. S. aureus walls were structurally more compact in the hydrated state and had a higher maximum charge density than M. lysodeikticus walls. However, they were less responsive to changes in electrostatic interactions, apparently because of less mechanical compliance. In media of nearly neutral pH, S. aureus walls had a net positive charge whereas M. lysodeikticus walls had a net negative charge. These charge differences were reflected in Donnan distributions of mobile ions between wall phases and bulk medium phases. Cell walls of unfractionated cocci also could be made to swell and contract, and wall tonus in intact cells appeared to be set partly by electrostatic interactions and partly by mechanical tension in the elastic structures due to cell turgor pressure. The experimental results led to the conclusions that bacterial cell walls have many of the properties of polyelectrolyte gels and that peptidoglycans are flexible polymers. A reasonable mechanical model for peptidoglycan structure might be a sort of three-dimensional rope ladder with relatively rigid, polysaccharide rungs and relatively flexible polypeptide ropes. Thus, the peptidoglycan network surrounding cocci appeared to be predominantly an elastic restraining structure rather than a rigid shell.
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Einolf CW, Carstensen EL. Passive electrical properties of microorganisms. IV. Studies of the protoplasts of Micrococcus lysodeikticus. Biophys J 1969; 9:634-43. [PMID: 4888132 PMCID: PMC1367541 DOI: 10.1016/s0006-3495(69)86408-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Observations of protoplasts of Micrococcus lysodeikticus show that removal of the cell wall of this organism decreases the dielectric constant by two orders of magnitude. The upper limit of the effective, homogeneous conductivity for the protoplast is 0.001 mho/m as compared with 0.045 mho/m for the intact cell. These results conclusively demonstrate the dominant effect of the cell wall on the low frequency dielectric properties of bacteria.
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