THE METABOLISM OF YEAST SPORULATION: III. RESPIRATION OF SPORULATING AND GROWING CELLS

1959 ◽  
Vol 5 (2) ◽  
pp. 153-159 ◽  
Author(s):  
J. J. Miller ◽  
O. Hoffmann-Ostenhof ◽  
Eszter Scheiber ◽  
O. Gabriel
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Growth Medium ◽  
Respiratory Quotient ◽  
The Other ◽  
Clear Correlation ◽  
Endogenous Respiration ◽  
Anaerobic Conditions ◽  
Sodium Pyruvate ◽  
Carbon Dioxide Output

Cells from growth medium had a strong endogenous respiration under aerobic conditions with a respiratory quotient of approximately unity. In M/300 glucose, their oxygen uptake was somewhat greater than the endogenous, but the aerobic carbon dioxide output was approximately twice the oxygen uptake. When such cells were incubated in buffer no change in their respiration in glucose was noted in 2 days, but when incubated in 0.3% acetate the respiratory quotient declined to 1.3–1.5. This decline was evident within six hours of the time the cells were placed in acetate. Glucose (0.1%) also depressed the respiratory quotient. With two other sporulation substrates, sodium pyruvate (0.13%) and lactic acid (0.1%), the effect was not so pronounced, and a fifth, dihydroxyacetone (0.1%), seemed to have little or no effect. Spores developed more rapidly and became more abundant in the acetate than in any of the other compounds. The changes in the respiratory quotient did not show a clear correlation with either the amount or the rapidity of sporulation in the five sporulation substrates. When cells were incubated in acetate or in glucose for a day under anaerobic conditions their respiratory quotient did not decline. Some success was obtained in separating sporulated from non-sporulated cells by centrifuging. No difference was noted in the respiration of sporulated and non-sporulated cells. The respiratory quotient of cells from sporulated cultures returned to values characteristic of growing cells after 2 to 4 hours in growth medium.

RESPIRATION OF INTACT CELLS OF A LOW-TEMPERATURE BASIDIOMYCETE

1966 ◽  
Vol 44 (8) ◽  
pp. 1077-1086 ◽  
Author(s):  
E. W. B. Ward
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Oxygen Uptake ◽  
Respiratory Quotient ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Endogenous Respiration ◽  
Starvation Period ◽  
Intact Cells ◽  
Exogenous Glucose

Conventional manometric procedures were used to measure oxygen uptake and carbon dioxide evolution by cells of a low-temperature basidiomycete. Total respiration was lowest and, relatively, endogenous respiration was highest in old cells. During starvation, endogenous respiration decreased but did so most rapidly in young cells. Maximum response to exogenous glucose was obtained from young cells after starvation. The respiratory quotient of endogenous respiration fell from 1.0 to approximately 0.7 during starvation, indicating a change in endogenous substrate. Conversely the respiratory quotient for exogenous respiration of added glucose increased with the starvation period. The level of oxidative assimilation of glucose was shown to be high (80-90%) and evidence was obtained that exogenous glucose did not suppress endogenous respiration.The optimum temperature for oxygen uptake was 25 °C, below which the Q10 was approximately 2. At 30 °C the rate, while initially highest, decreased during the 6-hour incubation period.The fungus utilized various compounds as carbon sources, but not sucrose in short-term experiments. Glucose, but not xylose was fermented, although the ratio of carbon dioxide to ethanol was not 1:1. Inhibition by fluoride, arsenite, iodoacetate, fluoroacetate, and malonate suggested that both glucose and xylose are respired at least in part by the Embden-Meyerof pathway and the tricarboxylic acid cycle. Endogenous respiration was only slightly affected by these inhibitors.

Dependence of mitosis and respiration in roots upon oxygen tension

1961 ◽  
Vol 154 (954) ◽  
pp. 109-129 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Oxygen Tension ◽  
Oxygen Requirement ◽  
Anaerobic Conditions ◽  
Root Tips ◽  
Carbon Dioxide Output ◽  
Lower Oxygen ◽  
Oxygen Tensions ◽  
The Relationship

Excised pea-root tips were incubated for 4 h in gas mixtures containing 0.00001 to 100% oxygen, in order to determine the effect upon mitosis. Below 0.0005% oxygen, mitosis was completely arrested. Between 0.001 and 0.02% oxygen, cells initially in mitosis completed division, but no more cells started dividing. Between 0.05 and 0.2% oxygen, cells initially in interphase entered division, but did not finish. Above 0.5% oxygen, all cells not prevented from dividing by excision finished division within 4 h. After exposure to 0.05% oxygen for 4 h, an excessive proportion of cells was found in prophase; in 0.1% oxygen an excess of metaphases, and in 0.2% oxygen an excess of telophases resulted. The oxygen uptake and carbon dioxide output of root tips were measured in a range of oxygen tensions and in anaerobic conditions. The relationship between oxygen uptake and oxygen tension was hyperbolic; a half maximum rate of oxygen uptake was obtained at about 10% oxygen. It was concluded that the respiration of root tips was limited by slow diffusion of oxygen through the tissue. From the carbon dioxide output it was estimated that the amount of energy available to isolated root tips under anaerobic conditions was about 1% of that available under aerobic conditions. Possible mechanisms whereby extreme oxygen-lack could arrest mitosis were considered. It was shown that the arrest was not due to abolition of a gross supply of energy. No evidence was obtained as to what other mechanism might be operative. An hypothesis was formulated in an attempt to explain the complicated relationship between mitosis and oxygen tension. It was assumed that the visible phases of mitosis are immediately preceded by a phase with a higher requirement for oxygen than mitosis, and that preceding this is an earlier phase with a lower oxygen requirement than mitosis.

The effect of some salts on Thiobacillus thioparus

1969 ◽  
Vol 15 (3) ◽  
pp. 314-318 ◽  
Author(s):  
Paulina Keller
Keyword(s):  
Sodium Chloride ◽  
Oxygen Uptake ◽  
Growth Medium ◽  
Dead Sea ◽  
The Other ◽  
Endogenous Respiration ◽  
Cell Free Extract ◽  
Intact Cells ◽  
Thiobacillus Thioparus ◽  
Other Hand

The effect of NaCl on Thiobacillus thioparus ATCC 8158 and on a strain of T. thioparus isolated from salt-rich Ein Bokek spring, near the Dead Sea, was investigated. Whereas the growth of T. thioparus ATCC 8158 was completely arrested by NaCl, KCl, or NaNO3 at a concentration of 0.3 M, the Ein Bokek strain tolerated 1.4 M of NaCl in the growth medium. Other salts (KCl, KNO3, CaCl2, MgCl2, and NaNO3) were significantly more toxic than NaCl. On the other hand, their effect on oxygen uptake by both strains was similar to that of NaCl.The thiosulfate-oxidizing system in cell-free extract was less affected by NaCl than that in the intact cells. Most of the effect of NaCl on this system could be attributed to inhibition of endogenous respiration. It was concluded that sodium chloride did not inhibit growth of T. thioparus through blocking its respiratory processes.

Breathing in brief exercise

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Metabolic Cost ◽  
Carbon Dioxide Tension ◽  
Minute Volume ◽  
Carbon Dioxide Output ◽  
Respiratory Minute Volume ◽  
Before And After

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960

Use of respiratory quotients in assessment of aerobic work capacity

1962 ◽  
Vol 17 (1) ◽  
pp. 47-50 ◽  
Author(s):  
B. Issekutz ◽  
N. C. Birkhead ◽  
K. Rodahl
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Work Load ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Carbon Dioxide Output ◽  
Ergometer Test ◽  
Aerobic Work Capacity ◽  
Bicycle Ergometer Test ◽  
Better Than

Oxygen uptake and carbon dioxide output were measured in 32 untrained subjects during exercise on the bicycle ergometer. It was shown that the work respiratory quotient (RQ) under standardized conditions can be used as a measure of physical fitness. ΔRQ (work RQ minus 0.75) increases logarithmically with the work load and maximal O2 uptake is reached at a ΔRQ value of 0.40. This observation offered the possibility of predicting the maximal O2 uptake of a person, based on the measurement of RQ during a single bicycle ergometer test at a submaximal load. For each work RQ between 0.95 and 1.15 a factor was presented, together with the aid of a simple equation, which gave a good approximation (generally better than ±10%) of the maximal O2 uptake.

scholarly journals A SYSTEM FOR THE CONTINUOUS MEASUREMENT OF OXYGEN UPTAKE AND CARBON DIOXIDE OUTPUT IN ARTIFICIALLY VENTILATED PATIENTS

1983 ◽  
Vol 55 (8) ◽  
pp. 791-800 ◽  
Author(s):  
A.M. HENDERSON ◽  
P.C. FORRESTER ◽  
R.F. ARMSTRONG ◽  
C.A. MOSSE ◽  
D. HALSALL
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Continuous Measurement ◽  
Carbon Dioxide Output ◽  
Ventilated Patients

Intratest reliability and test–retest reproducibility of the oxygen uptake efficiency slope in healthy participants

2009 ◽  
Vol 16 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Christophe Van Laethem ◽  
Johan De Sutter ◽  
Wim Peersman ◽  
Patrick Calders
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Exercise Duration ◽  
Peak Oxygen Uptake ◽  
Exercise Tests ◽  
Uptake Efficiency ◽  
Carbon Dioxide Output ◽  
Oxygen Uptake Efficiency Slope ◽  
Healthy Participants

Background The oxygen uptake efficiency slope (OUES) is a newer ventilatory exercise parameter, used in the evaluation of healthy participants and patients with cardiovascular disease. However, few data about the reliability and reproducibility of OUES are available. Our study assessed intratest reliability and test-retest reproducibility of OUES in healthy participants. Design and methods Eighteen participants (age 28 ± 6 years, BMI 22.1 ± 1.9 kg/m2, 10 men) performed two identical maximal exercise tests on a bicycle ergometer. To assess test-retest reproducibility, we performed Bland-Altman analysis and calculated the coefficient of repeatability of the main ventilatory variables. Results OUES remained stable during the second part of the exercise test. Mean values varied 2.4 ± 4.0% between OUES calculated at 70% (OUES70) and at 100% of exercise duration. Mean variation decreased to 1.4 ± 2.3% when OUES was calculated at 90% of exercise duration (OUES90). The Bland-Altman 95% limits of agreement for OUES90 were +3 and –6%, those for OUES70 were +11 and –8%. The coefficient of repeatability for OUES was 597 ml/min or 18.7% of the average value of repeated OUES measurements. These results were similar to those of peak oxygen uptake and minute ventilation/carbon dioxide output. However, the test-retest reproducibility for submaximal-derived values of OUES was lower, as we noted higher coefficients of repeatability for OUES90 and OUES70, increasing up to 27% of the average of repeated values. Conclusion OUES shows excellent intratest reliability and has a test-retest reproducibility that is similar to that of peak oxygen uptake and minute ventilation/carbon dioxide output slope. However, its reproducibility becomes higher when it is calculated from increasing levels of achieved exercise intensity.

Changes in Ventilation, Oxygen Uptake, and Carbon Dioxide Output during Recovery from Isoflurane Anesthesia

1989 ◽  
Vol 70 (5) ◽  
pp. 737-741 ◽  
Author(s):  
M. J. Clofolo ◽  
F. Clergue ◽  
C. Devillers ◽  
M. Ben Ammar ◽  
P. Viars
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Carbon Dioxide Output ◽  
Isoflurane Anesthesia

Physiological responses and air consumption during simulated firefighting tasks in a subway system

2010 ◽  
Vol 35 (5) ◽  
pp. 671-678 ◽  
Author(s):  
F. Michael Williams-Bell ◽  
Geoff Boisseau ◽  
John McGill ◽  
Andrew Kostiuk ◽  
Richard L. Hughson
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Energy Requirement ◽  
Average Energy ◽  
Peak Oxygen Uptake ◽  
Search And Rescue ◽  
Moderate Intensity ◽  
Physiological Strain ◽  
Carbon Dioxide Output ◽  
Subway System

Professional firefighters (33 men, 3 women), ranging in age from 30 to 53 years, participated in a simulation of a subway system search and rescue while breathing from their self-contained breathing apparatus (SCBA). We tested the hypothesis that during this task, established by expert firefighters to be of moderate intensity, the rate of air consumption would exceed the capacity of a nominal 30-min cylinder. Oxygen uptake, carbon dioxide output, and air consumption were measured with a portable breath-by-breath gas exchange analysis system, which was fully integrated with the expired port of the SCBA. The task involved descending a flight of stairs, walking, performing a search and rescue, retreat walking, then ascending a single flight of stairs to a safe exit. This scenario required between 9:56 and 13:24 min:s (mean, 12:10 ± 1:10 min:s) to complete, with an average oxygen uptake of 24.3 ± 4.5 mL·kg–1·min–1 (47 ± 10 % peak oxygen uptake) and heart rate of 76% ± 7% of maximum. The highest energy requirement was during the final single-flight stair climb (30.4 ± 5.4 mL·kg–1·min–1). The average respiratory exchange ratio (carbon dioxide output/oxygen uptake) throughout the scenario was 0.95 ± 0.08, indicating a high carbon dioxide output for a relatively moderate average energy requirement. Air consumption from the nominal “30-min” cylinder averaged 51% (range, 26%–68%); however, extrapolation of these rates of consumption suggested that the low-air alarm, signalling that only 25% of the air remains, would have occurred as early as 11 min for an individual with the highest rate of air consumption, and at 16 min for the group average. These data suggest that even the moderate physical demands of walking combined with search and rescue while wearing full protective gear and breathing through the SCBA impose considerable physiological strain on professional firefighters. As well, the rate of air consumption in these tasks classed as moderate, compared with high-rise firefighting, would have depleted the air supply well before the nominal time used to describe the cylinders.

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