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.

Sodium Chloride and Pathogenic Bacteria in a Vacuum-Packed Minced-Meat Product

1985 ◽  
Vol 48 (2) ◽  
pp. 150-155 ◽  
Author(s):  
H.-J. S. NIELSEN ◽  
P. ZEUTHEN
Keyword(s):  
Sodium Chloride ◽  
Salmonella Enteritidis ◽  
Pathogenic Bacteria ◽  
Storage Temperature ◽  
Meat Product ◽  
Chloride Concentration ◽  
Chloride Content ◽  
Inhibitory Effect ◽  
High Sodium ◽  
Salt Level

Development of Bacillus cereus, Salmonella enteritidis, Salmonella typhimurium and Yersinia enterocolitica in vacuum-packed Bologna-type sausage was highly influenced by sodium chloride level (brine concentrations 3.4, 4.5 and 6.0; 2.8 for salmonellae) with none of the bacteria growing at 6.0%. Growth of Staphylococcus aureus was unaffected even by the highest sodium chloride concentration used. Decreasing the storage temperature accentuated the inhibitory effect of sodium chloride on Y. enterocolitica and B. cereus. Initial numbers decreased slowly or remained static in sausage with a high sodium chloride content, when growth did not occur. At the low salt level, at 2–5°C, only Y. enterocolitica was not inhibited until the sodium chloride content was 4.5% and the storage temperature 2°C. At increased, but not unusual temperature, B. cereus could develop at 4.5% (12°C) and S. aureus at all salt levels (8–15°C).

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.

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>

Inhibition of Fatty Acid Synthetase in Halobacterium cutirubrum and Escherichia coli by High Salt Concentrations

1971 ◽  
Vol 49 (8) ◽  
pp. 953-958 ◽  
Author(s):  
E. L. Pugh ◽  
M. K. Wassef ◽  
M. Kates
Keyword(s):  
Fatty Acid ◽  
Sodium Chloride ◽  
Specific Activity ◽  
Fatty Acid Synthetase ◽  
Chloride Concentration ◽  
High Sodium ◽  
E Coli ◽  
Level Of Activity ◽  
Malonyl Coa ◽  
A Cell

A cell-free enzyme preparation from Halobacterium cutirubrum was shown to catalyze the biosynthesis of fatty acids from malonyl-CoA at zero sodium chloride concentration, with a specific activity about [Formula: see text] that of a similarly prepared fatty acid synthetase from E. coli. Both the H. cutirubrum synthetase and that from E. coli were strongly inhibited by high sodium chloride or potassium chloride concentrations (0.5–4 M). The malonyl-CoA: ACP transacylase, which catalyzes the first step in the fatty acid biosynthetic pathway, was shown to be strongly inhibited by salt in H. cutirubrum, but not in E. coli. It is concluded that H. cutirubrum contains a fatty acid synthetase system which normally operates at a very low level of activity as a result of inhibition by the high intracellular salt concentration present in this organism.

scholarly journals Nucleic acid enzymology of extremely halophilic bacteria. Halobacterium cutirubrum ribonucleic acid-dependent ribonucleic acid polymerase

1971 ◽  
Vol 121 (4) ◽  
pp. 629-633 ◽  
Author(s):  
B. Gregory Louis ◽  
P. S. Fitt
Keyword(s):  
Molecular Weight ◽  
Sodium Chloride ◽  
Nucleic Acid ◽  
Ribonucleic Acid ◽  
Halophilic Bacteria ◽  
Chloride Concentration ◽  
Nucleoside Triphosphate ◽  
Extreme Halophile ◽  
Sodium Chloride Concentration ◽  
The Stability

1. Crude extracts of the extreme halophile Halobacterium cutirubrum contain separable DNA-dependent and RNA-dependent RNA polymerases. 2. The RNA-dependent enzyme has been purified about 2800-fold. 3. It requires RNA, preferably of high molecular weight, and all four ribonucleoside triphosphates to incorporate 14C-labelled nucleoside triphosphate into an acid-insoluble, ribonuclease-sensitive product. 4. Both the stability and activity of the RNA polymerase are relatively insensitive to changes in potassium chloride or sodium chloride concentration, but incorporation is stimulated by both Mg2+ and Mn2+. 5. The molecular weight of the enzyme is about 17000–18000.

scholarly journals Response of Lactobacillus plantarum VAL6 to challenges of pH and sodium chloride stresses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Phu-Tho Nguyen ◽  
Thi-Tho Nguyen ◽  
Thi-Ngoc-Tuyen Vo ◽  
Thi-Thanh-Xuan Nguyen ◽  
Quoc-Khanh Hoang ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Mrna Expression ◽  
Lactobacillus Plantarum ◽  
Stress Condition ◽  
Chloride Concentration ◽  
Monosaccharide Composition ◽  
High Sodium ◽  
F Gene ◽  
Exopolysaccharide Biosynthesis ◽  
Galactose Content

AbstractTo investigate the effect of environmental stresses on the exopolysaccharide biosynthesis, after 24 h of culture at 37 °C with pH 6.8 and without sodium chloride, Lactobacillus plantarum VAL6 was exposed to different stress conditions, including pH (pHs of 3 and 8) and high sodium chloride concentration treatments. The results found that Lactobacillus plantarum VAL6 exposed to stress at pH 3 for 3 h gives the highest exopolysaccharide yield (50.44 g/L) which is 6.4 fold higher than non-stress. Under pH and sodium chloride stresses, the mannose content in exopolysaccharides decreased while the glucose increased in comparison with non-stress condition. The galactose content was highest under stress condition of pH 8 meantime rhamnose content increased sharply when Lactobacillus plantarum VAL6 was stressed at pH 3. The arabinose content in exopolysaccharides was not detected under non-stress condition but it was recorded in great amounts after 3 h of stress at pH 3. In addition, stress of pH 8 triggered the mRNA expression of epsF gene resulting in galactose-rich EPS synthesis. According to our results, the stresses of pH and sodium chloride enhance the production and change the mRNA expression of epsF gene, leading to differences in the monosaccharide composition of exopolysaccharides.

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.

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