Viability and respiratory activity ofPseudomonas syringaecells starved in buffer

1995 ◽  
Vol 41 (4-5) ◽  
pp. 372-377 ◽  
Author(s):  
João P. S. Cabral
Keyword(s):  
Oxygen Consumption ◽  
Electron Transport ◽  
Pseudomonas Syringae ◽  
Respiratory Activity ◽  
Bacterial Cells ◽  
Intact Cells ◽  
Rate Of Oxygen Consumption ◽  
Metabolic Activities ◽  
Different Levels ◽  
Number Of Cells

Pseudomonas syringae cells starved in buffer released orcinol-reactive molecules and materials that absorbed ultraviolet light. The number of cells culturable in nutrient medium decreased more rapidly than the number of intact particles determined by microscopy. The results suggested that starvation resulted in the lysis of an increasing number of cells, and that a fraction of the intact particles were not culturable. Starvation also resulted in a decrease in the rate of oxygen consumption with acetate, glycerol, and succinate, but at different levels. Whereas the respiration of acetate and glycerol decreased concomitantly with culturability, the respiration of succinate decreased to levels similar to the concentration of intact cells, suggesting that all intact particles respired the succinate, but only the culturable cells respired the acetate and glycerol. The results suggest that measuring the activity of the electron-transport system can overestimate the viability of starved bacterial cells, and that complex metabolic activities such as the respiration of acetate and glycerol are probably better suited for the evaluation of this parameter.Key words: Pseudomonas syringae, starvation, culturability, viability, respiration.

RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: IV. INFLUENCE OF CARBON DIOXIDE AND OXYGEN

1964 ◽  
Vol 42 (5) ◽  
pp. 847-856 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Partial Pressure ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Partial Pressure Of Oxygen ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate ◽  
Different Levels

Oxygen consumption was determined in relation to spontaneous activity and standard metabolism estimated by extrapolating the values to zero activity, Standard oxygen consumption was determined in relation to different partial pressures of carbon dioxide and oxygen for brook trout. Salvelinus fontinalis (Mitchill), at 10 °C, and carp, Cyprinus carpio Linnaeus, at 25 °C. In general, at each partial pressure of oxygen applied, standard oxygen consumption did not change significantly over the range of partial pressures of carbon dioxide followed. The relation for brook trout operated on a level characteristic of the partial pressure of oxygen. Although the effect of different levels of oxygen was not established for carp at 25 °C, it is presumed that the relation operated also in that species in a similar way.Acclimation to the different levels of carbon dioxide and oxygen to be tested was examined and, ordinarily, found not to change significantly the standard rate of oxygen consumption.

scholarly journals Measurement of β-oxidation capacity of biological samples by respirometry: a review of principles and substrates

2016 ◽  
Vol 310 (9) ◽  
pp. E715-E723 ◽  
Author(s):  
Edward Ojuka ◽  
Brittany Andrew ◽  
Nicole Bezuidenhout ◽  
Siddiqah George ◽  
Gerald Maarman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Oxygen Consumption ◽  
Biological Samples ◽  
Short Chain ◽  
Intact Cells ◽  
Permeabilized Cells ◽  
Isolated Mitochondria ◽  
Chain Acyl ◽  
Rate Of Oxygen Consumption

Oxidation of fatty acids is a major source of energy in the heart, liver, and skeletal muscle. It can be measured accurately using respirometry in isolated mitochondria, intact cells, and permeabilized cells or tissues. This technique directly measures the rate of oxygen consumption or flux at various respiratory states when appropriate substrates, uncouplers, and inhibitors are used. Acylcarnitines such as palmitoylcarnitine or octanoylcarnitine are the commonly used substrates. The β-oxidation pathway is prone to feedforward inhibition resulting from accumulation of short-chain acyl-CoA and depletion of CoA, but inclusion of malate or carnitine prevents accumulation of these intermediaries and CoA depletion.

scholarly journals Recovery heat in muscular contraction without lactic acid formation

1931 ◽  
Vol 108 (757) ◽  
pp. 279-301 ◽  
Keyword(s):  
Acetic Acid ◽  
Oxygen Consumption ◽  
Lactic Acid ◽  
Muscular Contraction ◽  
Acid Formation ◽  
Anaerobic Conditions ◽  
Spontaneous Breakdown ◽  
Rate Of Oxygen Consumption ◽  
Resting Muscle

In a comparison of muscles poisoned with mono-iodo-acetic acid (IAA) in the presence and in the absence of oxygen respectively, Lundsgaard (1930) found:- (1) That the spontaneous breakdown of phosphagen in poisoned resting muscle is much more rapid under anaerobic conditions. (2) That the onset of the characteristic contracture produced by IAA is accompanied always by an increase in the rate of oxygen consumption.

Proximal tubule dysfunction in cystine-loaded tubules: effect of phosphate and metabolic substrates

1996 ◽  
Vol 271 (3) ◽  
pp. F717-F722
Author(s):  
G. Bajaj ◽  
M. Baum
Keyword(s):  
Oxygen Consumption ◽  
Proximal Tubule ◽  
Tricarboxylic Acid Cycle ◽  
Dimethyl Ester ◽  
Proximal Tubules ◽  
Intracellular Atp ◽  
Metabolic Substrates ◽  
Rate Of Oxygen Consumption ◽  
Intracellular Phosphate

Intracellular cystine loading by use of cystine dimethyl ester (CDME) results in a generalized inhibition in proximal tubule transport due, in part, to a decrease in intracellular ATP. The present study examined the importance of phosphate and metabolic substrates in the proximal tubule dysfunction produced by cystine loading. Proximal tubule intracellular phosphorus was 1.8 +/- 0.1 in control tubules and 1.1 +/- 0.1 nmol/mg protein in proximal tubules incubated in vitro with CDME P < 0.001). Infusion of sodium phosphate in rabbits and subsequent incubation of proximal tubules with a high-phosphate medium attenuated the decrease in proximal tubule respiration and prevented the decrease in intracellular ATP with cystine loading. Tricarboxylic acid cycle intermediates have been shown to preserve oxidative metabolism in phosphate-depleted proximal tubules. In proximal tubules incubated with either 1 mM valerate or butyrate, there was a 42 and 34% reduction (both P < 0.05) in the rate of oxygen consumption with cystine loading. However, tubules incubated with 1 mM succinate or citrate had only a 13 and 14% P = NS) reduction in the rate of oxygen consumption, respectively. These data are consistent with a limitation of intracellular phosphate in the pathogenesis of the proximal tubule dysfunction with cystine loading.

scholarly journals EFFECTS OF AZIDE AND CHLORETONE ON THE SODIUM AND POTASSIUM CONTENTS AND THE RESPIRATION OF FROG SCIATIC NERVES

1958 ◽  
Vol 41 (5) ◽  
pp. 959-988 ◽  
Author(s):  
W. P. Hurlbut
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Depression ◽  
Conduction Block ◽  
Slow Conduction ◽  
Ionic Distribution ◽  
Rate Of Oxygen Consumption ◽  
Sciatic Nerves ◽  
Time Courses ◽  
Sodium And Potassium

Azide (0.2 to 5.0 mM) and chloretone (2.0 to 15.0 mM) reversibly inhibited 20 to 90 per cent of the resting respiration of frog sciatic nerves, and caused a loss of potassium and a gain of sodium in this tissue. The changes in ionic contents that developed after 5 or 10 hours were roughly correlated with the degree of respiratory depression, but the time courses of these changes were different with the two reagents. In azide these changes appeared to begin immediately, while in chloretone, at concentrations between 3.0 and 5.0 mM, the ionic shifts developed after a delay of several hours. Fifteen millimolar chloretone produced immediate changes in ionic contents several times greater than those produced by anoxia. The changes in ionic distribution produced in 5 hours by anoxia, 5.0 mM azide, or 5.0 mM chloretone were at least partially reversible; those produced by 15.0 mM chloretone were irreversible. With the exception of 15.0 mM chloretone the ionic shifts produced by these reagents may be due primarily to the depression of the respiration, although there are indications that azide acts, in addition, by another pathway. Concentrations of azide or chloretone that depressed the resting rate of oxygen consumption more than 50 per cent produced a slow conduction block, while 15.0 mM chloretone blocked conduction within 15 minutes.

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