In situ determination of kinetic parameters for biofilms: Isolation and characterization of oligotrophic biofilms

Abstract Objective This study was conducted to isolate and characterize lytic bacteriophages for pathogenic Escherichia coli from chicken and beef offal, and analyze their capability as biocontrol for several foodborne pathogens. Methods done in this research are bacteriophage isolation, purification, titer determination, application, determination of host range and minimum multiplicity of infection (miMOI), and bacteriophage morphology. Results Six bacteriophages successfully isolated from chicken and beef offal using EPEC and EHEC as host strain. Bacteriophage titers observed between 109 and 1010 PFU mL−1. CS EPEC and BL EHEC bacteriophage showed high efficiency in reduction of EPEC or EHEC contamination in meat about 99.20% and 99.04%. The lowest miMOI was 0.01 showed by CS EPEC bacteriophage. CI EPEC and BL EPEC bacteriophage suspected as Myoviridae family based on its micrograph from Transmission Electron Microscopy (TEM). Refers to their activity, bacteriophages isolated in this study have a great potential to be used as biocontrol against several foodborne pathogens.

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Modified ferron assay for speciation characterization of hydrolyzed Al(III): a precise k value based judgment

Water Science & Technology ◽

10.2166/wst.2009.066 ◽

2009 ◽

Vol 59 (4) ◽

pp. 823-832 ◽

Cited By ~ 3

Author(s):

Ye Changqing ◽

Wang Dongsheng ◽

Wu Xiaohong ◽

Qu Jiuhui ◽

John Gregory

Keyword(s):

Kinetic Constant ◽

Nonlinear Least Squares ◽

Precise Determination ◽

K Value ◽

First Order ◽

First Order Kinetics ◽

Parallel Reactions

The speciation of Al-OH complexes in terms of Ala, Alb and Alc could be achieved by traditional ferron assay and Alb is generally considered as Al13, however, the inherent correlation between them remains an enigma. This paper presents a modified ferron assay to get precise determination of Al13 using nonlinear least squares analysis, and to clarify the correlation between Alb and Al13. Two parallel reactions conforming to pseudo-first-order kinetics can simulate the complicate reactions between polynuclear complexes and ferron successfully. Four types of experimental kinetic constant (k value) of Al-OH complexes can be observed by this method when investigating three typical aluminium solutions. Comparing with the results of 27Al NMR, the species with moderate kinetics around 0.001 s−1 can be confirmed to resemble to Al13 polycation. The other types of kinetics are also well-regulated in partially neutralized aluminium solutions with various OH/Al ratios (b values) in the range 0 ∼ 2.5. It would provide potential means to trace the in-situ formation of Al13 in dilute solutions such as coagulation with Al-based coagulants

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Isolation and Characterization of a Chlorogenic Acid Esterase from Aspergillus niger

Zeitschrift für Naturforschung C ◽

10.1515/znc-1980-3-407 ◽

1980 ◽

Vol 35 (3-4) ◽

pp. 209-212 ◽

Cited By ~ 17

Author(s):

B. Schöbel ◽

W. Pollmann

Keyword(s):

Enzyme Activity ◽

Chlorogenic Acid ◽

Divalent Cations ◽

Hydrolysis Product ◽

The Other ◽

Temperature Optimum ◽

Pig Liver ◽

Isolation And Characterization

Abstract The isolation and characterization of a specific chlorogenic acid esterase is described. The enzyme activity is measured by determination of the hydrolysis product caffeic acid. The enzyme had been concentrated by means of ultrafiltration and column-chromatography. The pH- and temperature optimum were 6.5 and 45 °C respectively. Divalent cations were not required for the enzyme activity. As other esterases, this enzyme is inhibited by di-isopropyl-phosphorofluoridate. The Km-value is 0.70 mᴍ chlorogenic acid, the molecular weight 240000. The described enzyme is specific for chlorogenic acid. On the other hand a typical unspecific esterase like the pig liver esterases does not split chlorogenic acid. The isoelectric focusing reveals several isoenzymes of chlorogenase within a pI-range of 4.0-4.5.

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In situ structure and force characterization of 2D nano-colloids at the air/water interface

Soft Matter ◽

10.1039/c9sm01476d ◽

2019 ◽

Vol 15 (42) ◽

pp. 8475-8482

Author(s):

Giovanni Li-Destri ◽

Roberta Ruffino ◽

Nunzio Tuccitto ◽

Giovanni Marletta

Keyword(s):

Quantitative Determination ◽

Experimental Method ◽

Water Interface ◽

Liquid Interfaces ◽

Interaction Forces ◽

Air Water Interface

We have developed a novel experimental method, which enables quantitative determination of interaction forces between interfacial nanoparticles as a function of the inter-particle distance at liquid interfaces.

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In situ calibration and [H+] sensitivity of the fluorescent Na+indicator SBFI

AJP Cell Physiology ◽

10.1152/ajpcell.2001.280.6.c1623 ◽

2001 ◽

Vol 280 (6) ◽

pp. C1623-C1633 ◽

Cited By ~ 48

Author(s):

Abdoullah Diarra ◽

Claire Sheldon ◽

John Church

Keyword(s):

Ph Dependence ◽

Apparent Dissociation Constant ◽

Simple Method ◽

Standard Equation ◽

In Situ Calibration ◽

Apparent Decrease ◽

Calibration Techniques

Despite the popularity of Na+-binding benzofuran isophthalate (SBFI) to measure intracellular free Na+ concentrations ([Na+]i), the in situ calibration techniques described to date do not favor the straightforward determination of all of the constants required by the standard equation (Grynkiewicz G, Poenie M, and Tsien RY. J Biol Chem 260: 3440–3450, 1985) to convert the ratiometric signal into [Na+]. We describe a simple method in which SBFI ratio values obtained during a “full” in situ calibration are fit by a three-parameter hyperbolic equation; the apparent dissociation constant ( K d) of SBFI for Na+ can then be resolved by means of a three-parameter hyperbolic decay equation. We also developed and tested a “one-point” technique for calibrating SBFI ratios in which the ratio value obtained in a neuron at the end of an experiment during exposure to gramicidin D and 10 mM Na+is used as a normalization factor for ratios obtained during the experiment; each normalized ratio is converted to [Na+]i using a modification of the standard equation and parameters obtained from a full calibration. Finally, we extended the characterization of the pH dependence of SBFI in situ. Although the K d of SBFI for Na+ was relatively insensitive to changes in pH in the range 6.8–7.8, acidification resulted in an apparent decrease, and alkalinization in an apparent increase, in [Na+]i values. The magnitudes of the apparent changes in [Na+]ivaried with absolute [Na+]i, and a method was developed for correcting [Na+]i values measured with SBFI for changes in intracellular pH.

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Protocol for Isolation and Characterization of In Situ Fixed Quiescent Muscle Stem Cells

STAR Protocols ◽

10.1016/j.xpro.2020.100128 ◽

2020 ◽

Vol 1 (3) ◽

pp. 100128

Author(s):

Lu Yue ◽

Tom H. Cheung

Keyword(s):

Stem Cells ◽

Muscle Stem Cells ◽

Isolation And Characterization

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Isolation and characterization of a zebra finch aromatase cDNA: in situ hybridization reveals high aromatase expression in brain

Molecular Brain Research ◽

10.1016/0169-328x(94)90136-8 ◽

1994 ◽

Vol 24 (1-4) ◽

pp. 227-237 ◽

Cited By ~ 100

Author(s):

P. Shen ◽

C.W. Campagnoni ◽

K. Kampf ◽

B.A. Schlinger ◽

A.P. Arnold ◽

...

Keyword(s):

In Situ Hybridization ◽

Zebra Finch ◽

Aromatase Expression ◽

Isolation And Characterization

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Isolation and characterization of the urothelial lumenal plasma membrane.

The Journal of Cell Biology ◽

10.1083/jcb.73.2.382 ◽

1977 ◽

Vol 73 (2) ◽

pp. 382-399 ◽

Cited By ~ 28

Author(s):

J S Caruthers ◽

M A Bonneville

Keyword(s):

Plasma Membrane ◽

Sodium Dodecyl ◽

Modified Technique ◽

Sialic Acid Content ◽

Polarity Index ◽

Total Sialic Acid ◽

Isolation And Characterization ◽

A Value

The lumenal plasma membrane has been isolated from transitional epithelial cells (urothelium) lining the urinary bladder in sheep by a modified technique involving treatment with hypotonic thioglycolate. The isolated membranes, like those in situ, are distinguished morphologically by arrays of hexagonal particles (in plague regions) separated by smooth interplaque regions. These plaque regions, specifically, can be isolated from the lumenal plasma membrane. Of the proteins constituting the lumenal plasma membrane, five were found to characterize the plaque regions and, in particular, the 33,000-dalton species appears to be most heavily concentrated in the sodium dodecyl sulfate-polyacrylamide gel pattern of the isolated plaque regions. Lipid analyses showed that there are approximately 0.93 mg of phospholipid and 0.27 mg of cholesterol for each milligram of protein, giving a value of 55% lipids and 45% proteins for the composition of the lumenal plasma membrane. The total sialic acid content was measured to be approximately 0.038 micronmol/mg protein for the plasma membrane. Several plasma membrane marker enzymes were found to be associated with the lumenal plasma membrane fraction, but only the 5'-nucleotidase activity was found to be further enriched in the plaque region fraction. Amino acid analysis of the intrinsic proteins of the plaques indicated a polarity index of 45%.

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