Effect of glucose and pH on growth and enterotoxin B synthesis by Staphylococcus aureus, strain S6, after heat injury in sodium or potassium phosphate buffer

1973 ◽  
Vol 19 (7) ◽  
pp. 823-829 ◽  
Author(s):  
A. Hurst ◽  
D. L. Collins-Thompson ◽  
H. Kruse
Keyword(s):  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Aureus Strain ◽  
Lag Phase ◽  
Potassium Phosphate Buffer ◽  
Heat Injury ◽  
Glucose Levels ◽  
K Cells ◽  
Enterotoxin B ◽  
Straight Lines

Cells injured by heating at 52C for 15 min in sodium (Na cells) or potassium phosphate buffer (K cells) were allowed to grow and recover in media containing 0, 0.1%, and 1.0% glucose. Growth, acid, and enterotoxin B production was followed and compared with that of unheated control cells. Control cells growing in 0 and 0.1% glucose first lowered the pH, but injured cells did not. Straight lines were obtained from growth experiments when the ratio enterotoxin B/pH versus time was plotted. Statistical analysis of the slopes showed that Na cells differed from K cells. In 1.0% glucose, Na cells produced less acid than K cells. Na cells were 80%, control cells were 90%, and K cells were 99% repressed in their enterotoxin B synthesis. At all glucose levels, the lag phase of Na cells was about 2 h shorter than that of K cells. Heat injury caused a 30–40% loss of K+, but Na cells gained Na+ (34%) and K cells lost Na+ (28%). The K/Na ratio of Na cells was 2.75 and that of K cells was 15.75. It is argued that this difference could account for the differences observed between Na cells and K cells but cannot account for the total injury phenomenon.

Synthesis of enterotoxin B by Staphylococcus aureus strain S6 after recovery from heat injury

1973 ◽  
Vol 19 (12) ◽  
pp. 1463-1468 ◽  
Author(s):  
D. L. Collins-Thompson ◽  
A. Hurst ◽  
H. Kruse
Keyword(s):  
Heat Treatment ◽  
Staphylococcus Aureus ◽  
Salt Tolerance ◽  
Sodium Phosphate ◽  
Potassium Phosphate ◽  
Aureus Strain ◽  
Heat Injury ◽  
K Cells ◽  
Enterotoxin B ◽  
And Control

After sublethal heat treatment of Staphylococcus aureus S6 at 52C for 15 min in either 0.1 M sodium phosphate (Na cells) or 0.1 M potassium phosphate (K cells), more than 99% of the cells were unable to grow on a medium containing 7.5% NaCl. When placed in H and K medium the survivors recovered their salt tolerance and grew after a lag of 3 h (Na cells) or 5 h (K cells). In the absence of glucose, the total amount of enterotoxin B synthesized by the Na and K cells was similar to the control cells. Addition of 0.1% glucose to the medium increased the total amount of toxin formed by Na, K, and control cells.

scholarly journals Protecting ultra- and hyperhydrophilic implant surfaces in dry state from loss of wettability

2016 ◽  
Vol 2 (1) ◽  
pp. 557-560 ◽  
Author(s):  
Steffen Lüers ◽  
Markus Laub ◽  
Herbert P. Jennissen
Keyword(s):  
Dental Implants ◽  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Optimal System ◽  
Potassium Phosphate Buffer ◽  
Long Time ◽  
Optical Appearance

AbstractUltrahydrophilic titanium miniplates with sandblasted and acid etched (SLA) surfaces were protected from loss of hydrophilicity by an exsiccation layer of salt and stored in a dry state. Various salts in different concentrations were tested in respect to their conservation capacity and optical appearance. Potassium phosphate buffer in a specified composition appeared to be optimal. This optimal system was applied in a long time storage experiment showing no loss of hydrophilicity over years. It was also transferred with success to hyperhydrophilic dental implants.

scholarly journals An Elution Procedure for Visualization of Adult Hemoglobins in Human Blood Smears

Blood ◽  
1974 ◽  
Vol 43 (2) ◽  
pp. 239-242 ◽  
Author(s):  
David Kabat
Keyword(s):  
Cord Blood ◽  
Human Blood ◽  
Phosphate Buffer ◽  
Newborn Infants ◽  
Potassium Phosphate ◽  
Fetal Hemoglobin ◽  
Potassium Phosphate Buffer ◽  
Blood Smears

Abstract A procedure is described for visualization of normal and mutant adult hemoglobins in human blood smears. After extraction of blood smears with a concentrated potassium phosphate buffer (2.76 M, pH 7.2), erythrocytes that had adult hemoglobins stained bright red with erythrosin, whereas cells that had only fetal hemoglobin appeared as clear ghosts. Analyses of cord blood from newborn infants indicate that, although most erythrocytes contain only Hb F and a few contain only Hb A, many contain both hemoglobins A and F.

Repair of salt tolerance and recovery of lost D-alanine and magnesium following sublethal heating of Staphylococcus aureus are independent events

1981 ◽  
Vol 27 (6) ◽  
pp. 627-632 ◽  
Author(s):  
A. Hurst ◽  
A. Hughes
Keyword(s):  
Staphylococcus Aureus ◽  
Salt Tolerance ◽  
Phosphate Buffer ◽  
Synthetic Medium ◽  
Potassium Phosphate ◽  
Complex Media ◽  
Rich Medium ◽  
Potassium Phosphate Buffer ◽  
Heat Damage ◽  
Independent Events

Sublethal heating of Staphylococcus aureus S6 in potassium phosphate buffer caused loss of salt tolerance, D-alanine, and magnesium. During incubation in rich complex media all three of the damaged sites were repaired. Repair occurred more slowly but went to completion in a dilute synthetic medium (DSM), free of D-ala. DSM plus penicillin or D-cycloserine allowed repair of salt tolerance but recovery of normal levels of D-ala or Mg was prevented. When DSM-repaired cells were cultured into fresh rich medium they grew rapidly after a short lag. Cells which had acquired their salt tolerance in DSM plus cycloserine and were D-ala and Mg deficient grew slowly and had a lag of 3 h. We suggest that heat damage has two separate primary targets in S. aureus cells: the membrane, which is manifested by loss of salt tolerance, and a second site, possibly teichoic acids, manifested by loss of D-ala and Mg.

scholarly journals Purification and general properties of δ-aminolaevulate dehydratase from Nicotiana tabacum L.

1969 ◽  
Vol 114 (2) ◽  
pp. 331-337 ◽  
Author(s):  
A. S. Shetty ◽  
G. W. Miller
Keyword(s):  
Activation Energy ◽  
Nicotiana Tabacum ◽  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Optimum Temperature ◽  
Thiol Groups ◽  
Potassium Phosphate Buffer ◽  
Tobacco Leaves ◽  
General Properties ◽  
Nicotiana Tabacum L

1. δ-Aminolaevulate dehydratase (EC 4.2.1.24) was purified 80-fold from tobacco leaves and its properties were studied. 2. The enzyme had optimum pH7·4 in potassium phosphate buffer, Km6·25×10−4m at 37° and pH7·4, optimum temperature 45° and an activation energy of 11100 cal./mole. 3. The enzyme lost activity when prepared in the absence of cysteine, and this activity was only partly restored by the later addition of thiols. Reagents for thiol groups inactivated the enzyme. 4. Mg2+ was essential for activity, and EDTA and Fe2+ were inhibitory; Mn2+ was an activator or an inhibitor depending on the concentration.

Factors that Influence Germination and Mycoherbicidal Activity ofAlternaria cassiae

1991 ◽  
Vol 5 (1) ◽  
pp. 82-86 ◽  
Author(s):  
Donald J. Daigle ◽  
Peter J. Cotty
Keyword(s):  
Relative Humidity ◽  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Tween 80 ◽  
Growth Chamber ◽  
Potassium Phosphate Buffer ◽  
Potato Dextrose Broth ◽  
Leaf Stage ◽  
True Leaf

The influences of pH, surfactants, and nutrients on germination were investigated to develop a basis for improvement ofAlternaria cassiaemycoherbicide formulations. In vitro results indicated that a formulation with a pH of approximately 6.5 containing 0.1 to 1% Tween 80, 0.02 M potassium phosphate buffer, and 1% dehydrated potato dextrose broth best promoted germination. Sicklepod plants at the 2 to 3 true-leaf stage were sprayed with test solutions, incubated in the dark at 100% relative humidity (28 C) for 6 h, and placed in a growth chamber maintained at 30 C. Assessment of the plants after 2 d indicated that the ability of the formulation components to induce germination ofAlternaria cassiaein vitro corresponded well with their ability to improve infection of sicklepod seedlings.

Acceleration of hemoglobin C crystallization by hemoglobin S

Blood ◽  
1989 ◽  
Vol 74 (5) ◽  
pp. 1823-1825
Author(s):  
MJ Lin ◽  
RL Nagel ◽  
RE Hirsch
Keyword(s):  
Gel Electrophoresis ◽  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Potassium Phosphate Buffer ◽  
Time Intervals ◽  
Agar Gel ◽  
Hemoglobin C ◽  
Agar Gel Electrophoresis ◽  
Over Time

We previously reported that circulating hemoglobin (Hb) CC erythrocytes contain oxygenated HbC crystals with little or no HbF and that HbF inhibits in vitro crystallization of HbC. We now report that HbS accelerates in vitro crystallization of HbC. Crystals were formed in 1.8 mol/L potassium phosphate buffer, pH 7.4, at 30 degrees C and were counted in several time intervals with a hematocytometer. The hemoglobin composition of Millipore-isolated crystals and supernatant were also analyzed. Under the conditions selected, 100% HbS formed needle-shaped crystals only after two hours. Pure HbC does not form crystals within 15 minutes, whereas a ratio of 10% HbS:90% HbC forms 1,100 crystals/mm3, 20% HbS:80% HbC forms 370 crystals/mm3, and 30% HbS:70% HbC forms 5 crystals/mm3. Crystals formed in the presence of HbS are tetragonal, as are pure HbC crystals. As compared with 100% HbC, HbA or albumin mixed with HbC showed a decreased number of crystals as a result of dilution. Analysis of the Hb content of isolated crystals by citrate agar gel electrophoresis showed that HbS was rapidly incorporated into the crystal in the same ratio over time. These results demonstrate that HbS accelerates crystallization of HbC with respect to the rates of crystallization of any of these two Hbs separately, through a mechanism that involves cocrystallization. These results may be significant in understanding SC disease.

scholarly journals DEVELOPMENT OF A HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR ANALYZING DISODIUM 5′-GUANYLATE AND DISODIUM 5′-INOSINATE LEVELS IN FLAVOR ENHANCERS

2018 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Dwi Karina Natalia ◽  
Harmita . ◽  
Taufiq Indra Rukmana
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Flow Rate ◽  
Phosphate Buffer ◽  
Mobile Phase ◽  
High Performance ◽  
Potassium Phosphate ◽  
Array Detector ◽  
Potassium Phosphate Buffer ◽  
Chromatography Method

Objective: This study aimed to develop a selective analytical method for assessing disodium 5′-guanylate and disodium 5′-inosinate levels in flavorenhancers.Methods: The levels were assessed using high-performance liquid chromatography (HPLC) with a photodiode array detector (PDA) (wavelength=255 nm) and a SunFire® C18 column (250 mm × 4.6 mm × 5 μm). The mobile phase comprised a mixture of potassium phosphate buffer and anion pair reagent-hexane-1-sulfonic acid sodium salt - with a flow rate of 1.2 mL/min. The ion pair was used to generate a neutral equilibrium, whichresulted in increased retention of the analytes. Optimized analysis conditions were then validated regarding accuracy, precision, linearity, selectivity,and the limits of detection and quantification.Results: The average levels of disodium 5′-inosinate in the six analyzed samples were 0.24±1.46, 0.21±2.69, 0.58±3.26, 0.21±0.84, 0.22±3.59, and0.47±2.21%, respectively. Regarding disodium 5′-guanylate, the average levels were 0.15±2.85, 0.15±0.12, 0.41±3.80, 0.16±1.72, 0.27±1.18, and0.34±1.83, respectively.Conclusion: The optimal conditions for analyzing disodium 5′-guanylate and disodium 5′-inosinateusing HPLC with a PDA and SunFire C18 columnwere λ=255 nm, a mobile phase of potassium phosphate buffer and sodium hexane sulfonate, and a flow rate of 1.2 mL/min. For disodium 5′-inosinate,its average levels in samples A–F were 0.24±1.46, 0.21±2.69, 0.58±3.26, 0.21±0.84, 0.22±3.59, and 0.47±2.21%, respectively. Meanwhile, the averagelevels of disodium 5′-guanylate in the samples were 0.15±2.85, 0.15±0.12, 0.41±3.80, 0.16±1.72, 0.27±1.18, and 0.34±1.83%, respectively.

Subcellular localization of actin in chlorella

1984 ◽  
Vol 42 ◽  
pp. 308-309
Author(s):  
A. Michaels ◽  
V. Kriho ◽  
L. Solomonson
Keyword(s):  
Polyethylene Glycol ◽  
Chlorella Vulgaris ◽  
Subcellular Distribution ◽  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Subcellular Location ◽  
Eukaryotic Cells ◽  
Growth Media ◽  
Potassium Phosphate Buffer ◽  
Immunocytochemical Techniques

Although most often thought of as a contractile protein, actin has been localized and isolated from many non-muscle eukaryotic cells. The function of actin has also been described in certain algal cells. However, little is known regarding the subcellular distribution of actin and its relationship to function in algal cells.Using the immunocytochemical techniques of Wolosewick and co-workers, we have determined the subcellular location of actin in the unicellular green algae, Chlorella vulgaris.Pellets of Chlorella were fixed in 0.25% glutaraldehyde (EMS) in growth media for 1 hr on ice. The cells were washed (2X) with 10mM potassium phosphate buffer, pH 7.5. These cells were maintained on ice in phosphate buffer until dehydration and embedding in polyethylene glycol (PEG) (MW3350). PEG is a water miscible wax which can be removed easily from the section.

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