EFFECT OF SALT CONCENTRATION ON THE EXTRACELLULAR NUCLEIC ACIDS OF MICROCOCCUS HALODENITRIFICANS

1957 ◽  
Vol 3 (5) ◽  
pp. 687-694 ◽  
Author(s):  
I. Takahashi ◽  
N. E. Gibbons
Keyword(s):  
Cell Wall ◽  
Sodium Chloride ◽  
Nucleic Acids ◽  
Lower Limit ◽  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Magnesium Ions ◽  
Divalent Ions ◽  
Salt Requirement

Labelled non-viscous cells of Micrococcus halodenitrificans were obtained in media containing P32 and 2 M sodium chloride and their growth then followed in salt concentrations ranging from 0.55 M, the lower limit of growth, to 3 M. At concentrations of 0.7 M and above, cells remained non-viscous and only traces of extracellular nucleic acids (NA) could be detected. At lower concentrations of salt, cells became viscous and the amount of extracellular NA increased as the concentration decreased. The distribution of P32 indicated that the source of the extracellular NA was intracellular. At the salt concentrations studied, the loss of NA was prevented by the addition of calcium or magnesium ions. However, sodium chloride seemed necessary to maintain the cell wall of M. halodenitrificans and the effect was supplemented by divalent ions. It is suggested that this may explain the salt requirement of this organism and possibly that of other halophilic bacteria.

THE EFFECT OF CHLORIDES OF MONOVALENT CATIONS, UREA, DETERGENTS, AND HEAT ON MORPHOLOGY AND THE TURBIDITY OF SUSPENSIONS OF RED HALOPHILIC BACTERIA

1961 ◽  
Vol 7 (5) ◽  
pp. 741-750 ◽  
Author(s):  
Dinah Abram ◽  
N. E. Gibbons
Keyword(s):  
Cell Wall ◽  
Sodium Chloride ◽  
Ionic Strength ◽  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Monovalent Cations ◽  
Abrupt Decrease ◽  
Ionic Detergents ◽  
Time Required ◽  
Sodium And Potassium

Suspensions of Halobacterium cutirubrum, grown and suspended in 4.0 M sodium chloride, showed on transfer to increasingly lower concentrations of sodium chloride an increase in turbidity followed by an abrupt decrease. When the suspensions were placed in potassium, rubidium, cesium, lithium, or ammonium chlorides, there was no increase in turbidity but usually a gradual decrease as the concentration of the salt is decreased. In potassium, rubidium, and cesium chlorides these changes were correlated with a change in morphology from rods, through transition forms, to spheres, similar to changes in NaCl, except that transition forms were found even at concentrations of 4.0 M. In lithium and ammonium chlorides there was an immediate change at 5.0 and 4.5 M respectively and two to five small spheres were formed from each rod. In mixtures of sodium and potassium chlorides the morphology of the cells depended on the ionic strength and concentration of sodium. Spheres were also produced by heating the cells to 60–70 °C, the time required for the conversion increasing with increasing salt concentration. In urea solutions the cells lysed, although at certain concentrations of urea and NaCl a change to small spheres was observed. Ionic detergents caused the cells to disintegrate gradually. These observations are taken as further evidence that sodium is required to maintain the cell wall of the red halophilic rods.

TURBIDITY OF SUSPENSIONS AND MORPHOLOGY OF RED HALOPHILIC BACTERIA AS INFLUENCED BY SODIUM CHLORIDE CONCENTRATION

1960 ◽  
Vol 6 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Dinah Abram ◽  
N. E. Gibbons
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Morphological Changes ◽  
Halophilic Bacteria ◽  
Chloride Concentration ◽  
Chloride Content ◽  
Wall Structure ◽  
Abrupt Decrease ◽  
High Sodium ◽  
Rigid Cell Wall

The optical densities of suspensions of cells of Halobacterium cutirubrum, H. halobium, or H. salinarium, grown in media containing 4.5 M sodium chloride, increase as the salt concentration of the suspending medium decreases, until a maximum is reached at about 2 M; below this concentration there is an abrupt decrease in optical density. The cells are rod shaped in 4.5 M salt and change, as the salt concentration decreases, through irregular transition forms to spheres; equal numbers of transition forms and spheres are present at the point of maximum turbidity, while spheres predominate at lower salt concentrations. Cells suspended in 3.0 M salt, although slightly swollen, are viable, but viability decreases rapidly with the more drastic changes in morphology at lower salt concentrations. Cells grown in the presence of iron are more resistant to morphological changes but follow the same sequence. Cells "fixed" with formaldehyde, at any point in the sequence, act as osmometers and do not rupture in distilled water although their volume increases 10–14 times. The results indicate that the red halophilic rods require a high sodium chloride content in their growth or suspending medium to maintain a rigid cell wall structure.

RELATION OF TEMPERATURE AND SODIUM CHLORIDE CONCENTRATION TO GROWTH AND MORPHOLOGY OF SOME HALOPHILIC BACTERIA

1961 ◽  
Vol 7 (4) ◽  
pp. 483-489 ◽  
Author(s):  
N. E. Gibbons ◽  
John I. Payne
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Maximum Yield ◽  
Chloride Concentration ◽  
Sodium Chloride Concentration ◽  
Halobacterium Salinarium ◽  
Irregular Shapes ◽  
Maximum Turbidity

The red halophiles, Halobacterium salinarium, H. cutirubrum, H. halobium, and Sarcina litoralis, grew most rapidly at salt concentrations of 20–25% and temperatures of 40–45 °C. Maximum turbidity was obtained at similar salt concentrations but at 35–40 °C. An unidentified colorless rod grew most rapidly at salt concentrations of 17.5–20% and temperatures of 40–50 °C, but produced maximum yield at 30 °C. The rod forms changed from long slender rods through irregular shapes to spheres as the salt concentration was decreased. At temperatures above the optimum, cells were very irregular, but otherwise temperature at any one salt concentration had little or no effect on the morphology.

THE GLYCEROL DEHYDROGENASES OF PSEUDOMONAS SALINARIA, VIBRIO COSTICOLUS, AND ESCHERICHIA COLI IN RELATION TO BACTERIAL HALOPHILISM

1954 ◽  
Vol 32 (1) ◽  
pp. 206-217 ◽  
Author(s):  
R. M. Baxter ◽  
N. E. Gibbons
Keyword(s):  
Escherichia Coli ◽  
Sodium Chloride ◽  
Potassium Chloride ◽  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Molar Concentration ◽  
Moderately Halophilic ◽  
E Coli ◽  
High Concentrations ◽  
Chloride Concentrations

Glycerol dehydrogenases from the extremely halophilic Pseudomonas salinaria and the moderately halophilic Vibrio costicolus are described and compared with the corresponding enzyme from the nonhalophilic Escherichia coli. The properties of all three enzymes are similar except their responses to salt concentration. The enzymes from E. coli and V. costicolus are most active at sodium chloride concentrations of about 0.25 M and 0.5 M respectively; that from P. salinaria is not only most active in the presence of 1.5 M NaCl but is irreversibly inactivated in the absence of salt. All three enzymes are more active in the presence of potassium chloride than of sodium chloride at any given molar concentration. These results suggest that the extremely halophilic bacteria contain high concentrations of salt and that their enzymes function maximally at these high concentrations. In contrast the moderately halophilic organisms contain relatively little salt and their enzymes are more comparable with those of nonhalophiles.

Isolation and characterization of Actinopolyspora halophila, gen. et sp. nov., an extremely halophilic actinomycete

1975 ◽  
Vol 21 (10) ◽  
pp. 1500-1511 ◽  
Author(s):  
Margaret B. Gochnauer ◽  
Gary G. Leppard ◽  
Prayad Komaratat ◽  
Morris Kates ◽  
Thomas Novitsky ◽  
...  
Keyword(s):  
Cell Wall ◽  
Culture Medium ◽  
Halophilic Bacteria ◽  
Diaminopimelic Acid ◽  
Type Iv ◽  
Isolation And Characterization ◽  
The Family ◽  
Salt Requirement ◽  
Halophilic Actinomycete

An actinomycete, isolated as a contaminant of a culture medium containing 25% NaCl, has been classified as Actinopolyspora halophila gen. et sp. nov. in the family Nocardiaceae. The morphology and biochemical characteristics of this organism distinguish it from other members of the family Nocardiaceae and other genera possessing a type IV cell wall. It requires high NaCl concentrations for growth and can grow in saturated NaCl. The lowest concentration permitting growth in liquid medium is 12%, and on solid medium, 10%. Colonies developing at lower salt concentrations contain holes resembling viral plaques. No growth occurred in a medium containing 30% KCl instead of NaCl. This organism can grow in simple media with NH4+ salts as nitrogen source and different sugars and other compounds as carbon source. Though it has a salt requirement almost as great as the extremely halophilic rods and cocci, it differs from these in containing diaminopimelic acid and in sensitivity to lysozyme; both properties suggest that it has a mucopeptide cell wall. It also contains some phospholipids common to other actinomycetes, but does not contain any phytanyl ether linked lipids characteristic of other extremely halophilic bacteria.

THE GLYCEROL DEHYDROGENASES OF PSEUDOMONAS SALINARIA, VIBRIO COSTICOLUS, AND ESCHERICHIA COLI IN RELATION TO BACTERIAL HALOPHILISM

1954 ◽  
Vol 32 (3) ◽  
pp. 206-217 ◽  
Author(s):  
R. M. Baxter ◽  
N. E. Gibbons
Keyword(s):  
Escherichia Coli ◽  
Sodium Chloride ◽  
Potassium Chloride ◽  
Salt Concentration ◽  
Halophilic Bacteria ◽  
Molar Concentration ◽  
Moderately Halophilic ◽  
E Coli ◽  
High Concentrations ◽  
Chloride Concentrations

Glycerol dehydrogenases from the extremely halophilic Pseudomonas salinaria and the moderately halophilic Vibrio costicolus are described and compared with the corresponding enzyme from the nonhalophilic Escherichia coli. The properties of all three enzymes are similar except their responses to salt concentration. The enzymes from E. coli and V. costicolus are most active at sodium chloride concentrations of about 0.25 M and 0.5 M respectively; that from P. salinaria is not only most active in the presence of 1.5 M NaCl but is irreversibly inactivated in the absence of salt. All three enzymes are more active in the presence of potassium chloride than of sodium chloride at any given molar concentration. These results suggest that the extremely halophilic bacteria contain high concentrations of salt and that their enzymes function maximally at these high concentrations. In contrast the moderately halophilic organisms contain relatively little salt and their enzymes are more comparable with those of nonhalophiles.

scholarly journals Effect of Xanthan and Arabic Gums on Foaming Properties of Pumpkin (Cucurbita pepo) Seed Protein Isolate

2013 ◽  
Vol 3 (1) ◽  
pp. 87 ◽  
Author(s):  
Quirino Dawa ◽  
Yufei Hua ◽  
Moses Vernonxious Madalitso Chamba ◽  
Kingsley George Masamba ◽  
Caimeng Zhang
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Seed Protein ◽  
Foam Stability ◽  
Chloride Concentration ◽  
Egg White ◽  
Protein Isolate ◽  
Foaming Properties ◽  
Ph Optimum ◽  
Pumpkin Seed

<p>Understanding how foaming properties of proteins are affected by factors such as pH, salt concentration and temperature is essential in predicting their performance and utilisation. In this study, the effects of pH and salt concentration were studied on the foaming properties of pumpkin seed protein isolate (PSPI) and PSPI- xanthan (XG)/Arabic (GA) gum blends. The foaming properties of the PSPI-GA/XG blends were also compared with egg white. Foam stability (FS) was significantly affected by pH with PSPI: GA (25:4) and PSPI: XG (25:1) having a significantly higher stability at pH 2 with the lowest foam stability at pH 4. Sodium chloride (0.2-1.0 M) did not significantly affect foaming properties although PSPI: GA (25:4) had the highest FC (89.33 ± 3.24%) and FS (76.83 ± 1.53 min) at 0.2 M sodium chloride concentration. The foaming capacity (FC) of PSPI: GA (25:4) blend (128.00 ± 0.91%) was significantly higher (<em>p </em><em>&lt; </em>0<em>.</em>05) than that of egg white (74.00 ± 1.33%) but its FS was significantly lower. It was further revealed that the FC of egg white (74.00 ± 1.33%) was comparable to the PSPI:XG (25:1) blend (74.00 ± 1.46%) but the FS for egg white (480.00 ± 2.67 min) was significantly higher (<em>p </em><em>&lt; </em>0<em>.</em>05) than the FS (116.21 ± 0.86 min) of PSPI:XG (25:1). The foaming properties of PSPI and PSPI-xanthan (XG)/Arabic (GA) blends were significantly affected by pH. Optimum foaming properties, PSPI:XG (25:1) and PSPI:GA (25:4) were observed at pH 2 and heat treatment temperature of 80 ºC.</p>

scholarly journals A MORPHOLOGICAL STUDY OF HALOBACTERIUM HALOBIUM AND ITS LYSIS IN MEDIA OF LOW SALT CONCENTRATION

1967 ◽  
Vol 34 (1) ◽  
pp. 365-393 ◽  
Author(s):  
Walther Stoeckenius ◽  
Robert Rowen
Keyword(s):  
Cell Wall ◽  
Cell Membrane ◽  
Salt Concentration ◽  
Prolonged Exposure ◽  
Structural Characteristics ◽  
Wall Material ◽  
Breakdown Product ◽  
Distilled Water ◽  
Fixation Techniques ◽  
A Cell

The reported absence of a cell wall in halobacteria cannot be confirmed. Improved fixation techniques clearly show a cell wall-like structure on the surface of these cells. A stepwise reduction of the salt concentration causes the release of cell wall material before the cell membrane begins to disintegrate. The cell membrane breaks up into fragments of variable but rather small size, which are clearly different from a 4S component reported by others to be the major breakdown product of the cell membrane. It appears more likely that the 4S component arises from the dissolution of the cell wall. A residue of large membranous sheets remains even after prolonged exposure of halobacteria envelopes to distilled water. The lipids in these sheets do not differ significantly from the lipids in the lysed part of the cell membrane. The sheets, however, contain a purple-colored substance, which is not present in the lysed part. The easily sedimentable residue that remains after lysis of the cells or envelopes in distilled water also contains "intracytoplasmic membranes" with unusual structural characteristics. They can also be identified in sections through intact bacteria or envelope preparations. Their function is at present unknown but seems to be related to the formation of gas vacuoles in these organisms.

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