Studies in the respiratory and carbohydrate metabolism of plant tissues. XII. Further studies of the formation of CO 2 and the changes in lactate, alcohol, sucrose, pyruvate and α -ketoglutarate in potato tubers in nitrogen and in air following anaerobic conditions

1963 ◽  
Vol 157 (968) ◽  
pp. 383-402 ◽  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Sugar Content ◽  
Close Correlation ◽  
Tricarboxylic Acid ◽  
Plant Tissues ◽  
Potato Tubers ◽  
Anaerobic Conditions ◽  
Sweet Potatoes ◽  
Pyruvate Oxidase ◽  
Oxidase System

A specific chromatographic method was used to show that, in air following anaerobiosis, lactate was oxidized to pyruvate and that the latter might be metabolized in the tricarboxylic acid cycle. Our earlier view (Barker & Mapson 1953 b )was thus confirmed. As was expected, both the form and mechanism of the outburst of CO 2 in air after nitrogen were simpler with fully sweet potatoes at 1 °C than with low-sugar potatoes at 10 °C. In the former the outburst of CO 2 appeared to be due only to consumption of lactate; in the latter the outburst of CO 2 was attributed in part to consumption of lactate and in part to change in sugar content. With certain stocks of fully sweet potatoes at 1 °C, the pyruvate oxidase system appeared to be saturated with substrate initially in air after nitrogen; moreover, after 22 days in nitrogen, the pyruvate oxidase system appeared to be almost, if not completely, inhibited. A general, but not a close, correlation was observed between the rates of aerobic respiration and of increase of lactate and output of CO 2 in nitrogen, the rates of these functions being affected by differences in sugar content (Barker 1933) and in metabolic state.

Studies in the respiratory and carbohydrate metabolism of plant tissues II. Interrelationship between the rates of production of carbon dioxide, of lactic and of alcohol in potato tubers under anaerobic conditions

1952 ◽  
Vol 140 (900) ◽  
pp. 385-403 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Pyruvic Acid ◽  
Sugar Content ◽  
Plant Tissues ◽  
Potato Tubers ◽  
Anaerobic Conditions ◽  
Glycolytic Intermediate ◽  
Pasteur Effect ◽  
High Sugar Content

Data, presented in part I of this communication, for the changes in air and in nitrogen in the rate of CO 2 production by potato tubers and in the contents of sugar, lactic acid, alcohol and other constituents, are analyzed and discussed. Certain features of the results indicate that in nitrogen a system producing lactic acid may be competing with systems in which either CO 2 or CO 2 and alcohol are formed, for a glycolytic intermediate, possibly pyruvic acid. Stoklasa (1904) observed the formation of lactic acid, together with a considerable amount of alcohol, in potatoes during anaerobiosis. In contrast, Kostytschew (1913) found no alcohol in low-sugar potatoes under anaerobic conditions, but a little alcohol in tubers of high sugar content. In our experiments, also with low-sugar potatoes, lactic acid but no alcohol was formed in the first phase of anaerobiosis; subsequently alcohol was produced in addition to lactic acid. Thus the results of previous workers are to a certain extent reconciled by the present study. When account is taken of the formation, under anaerobic conditions, of lactic acid and alcohol, as well as of CO 2 , a marked Pasteur effect is shown. The doubts expressed by Choudhury (1939) and Boswell & Whiting (1940), based solely on observations of CO 2 output, as to the existence of a Pasteur effect in potatoes are thus seen to be unjustified.

scholarly journals The pyruvate-oxidase system in brain and the tricarboxylic acid cycle*

1949 ◽  
Vol 45 (3) ◽  
pp. 320-325 ◽  
Author(s):  
R. V. Coxon ◽  
C. Liébecq ◽  
R. A. Peters
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Pyruvate Oxidase ◽  
Acid Cycle ◽  
Oxidase System

Studies in the respiratory and carbohydrate metabolism of plant tissues III. Experimental studies of the formation of carbon dioxide and of the changes in lactic acid and other products in potato tubers in air following anaerobic conditions

1953 ◽  
Vol 140 (901) ◽  
pp. 508-522 ◽  
Keyword(s):  
Lactic Acid ◽  
Anaerobic Metabolism ◽  
Soluble Fraction ◽  
Sugar Content ◽  
Experimental Studies ◽  
Plant Tissues ◽  
Potato Tubers ◽  
Anaerobic Conditions ◽  
The Third ◽  
After Effect

This paper is the third in a series dealing with the anaerobic metabolism of potato tubers. In the two earlier papers (Barker & Saifi 1952 a, b ) we considered the changes which occurred during exclusion of oxygen, in the rate of CO 2 production and in the contents o sugar, lactic acid, alcohol and of an unidentified alcohol-soluble fraction. This paper is concerned with the influence of air following a period of anaerobiosis. The data given in the present paper showed that on transfer from the anaerobic to the aerobic state there was an increase in the rate of CO 2 production above the normal aerobic level, followed by a fall towards this level. Associated with this so-called after-effect there was a rapid disappearance of the lactic acid which had accumulated during the period in nitrogen and a quick increase in the sugar content, followed by a slower decrease. These experimental results are analyzed in the fourth paper in the series (page 522).

scholarly journals Metabolic control and regulation of the tricarboxylic acid cycle in photosynthetic and heterotrophic plant tissues

2011 ◽  
Vol 35 (1) ◽  
pp. 1-21 ◽  
Author(s):  
WAGNER L. ARAÚJO ◽  
ADRIANO NUNES-NESI ◽  
ZORAN NIKOLOSKI ◽  
LEE J. SWEETLOVE ◽  
ALISDAIR R. FERNIE
Keyword(s):  
Metabolic Control ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Plant Tissues ◽  
Acid Cycle

Studies in the respiratory and carbohydrate metabolism of plant tissues. VII. Experimental studies with potato tubers of an inhibition of the respiration and of a ‘block’ in the tricarboxylic acid cycle induced by ‘oxygen poisoning’

1955 ◽  
Vol 143 (913) ◽  
pp. 523-549 ◽  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Experimental Studies ◽  
General Term ◽  
Tricarboxylic Acid ◽  
Pure Oxygen ◽  
Prolonged Treatment ◽  
Potato Tubers ◽  
Acid Cycle ◽  
Oxidation Reduction ◽  
Oxygen Poisoning

Prolonged treatment of potato tubers at 1° C with an atmosphere of pure oxygen eventually induces a marked inhibition of the rate of CO 2 output; there is also an accumulation of pyruvate and of 'citrate’ and a decrease in the contents of α -ketoglutarate and of malate as compared with potatoes held in air. These changes in the acids appear to be in accord with the development during sojourn in pure oxygen of a ‘block’ in the tricarboxylic acid cycle between ‘citrate’ and α -ketoglutarate. The indications in previous work (Barron, Link, Klein & Michel 1950; Barker & Mapson 1953 b ) that the tricarboxylic acid cycle may operate in potato tubers under certain metabolic conditions are thus supported. The treatment with pure oxygen also results in a progressive shift to the more oxidized state in the ascorbic acid and glutathione oxidation-reduction systems; finally, the potato tissue develops a brown discoloration presumably due to polyphenolase action. The change in the balance of the two oxidation-reduction systems towards oxidation may be caused, in part, by a reduced rate of regeneration of coenzyme II because of the ‘block’ in the tricarboxylic acid cycle. The paper also contains the results of preliminary experiments on the reversibility of the above changes. The data add to the knowledge of the varied metabolic phenomena which have been observed in many different types of living tissue, both plant and animal, and which are conveniently classified under the general term ‘oxygen poisoning’ (Stadie, Riggs & Haugaard 1944).

Studies in the respiratory and carbohydrate metabolism of plant tissues XIII. The influence of oxygen at high pressures in increasing and decreasing the respiration of potatoes at 15 °C

1963 ◽  
Vol 158 (971) ◽  
pp. 143-155 ◽  
Keyword(s):  
Carboxylic Acid ◽  
Carbohydrate Metabolism ◽  
High Pressures ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Total Carbon ◽  
Plant Tissues ◽  
Sugar Phosphate ◽  
Oxygen Inhibition ◽  
Acid Cycle

The CO 2 output of potatoes held at 15 °C in oxygen at a pressure of either 2 or 3 atm was first decreased, then increased and finally again decreased. The increase of CO 2 output was much larger than in carrots (Barker 1961); in oxygen at a pressure of 2 atm the rate of CO 2 output of potatoes was increased 4.6 fold; taking into account the accumulation of citrate, the ‘total carbon traffic’ was increased 5.6 fold in oxygen. This increase was believed to occur mainly in a pathway which was not the tricarboxylic acid cycle. As in potatoes held at 1 °C in an atmosphere of oxygen (Barker & Mapson 1955), citrate accumulated and α -ketoglutarate decreased in potatoes, held at 15 °C in oxygen at pressures of 2 or 3 atm; these changes were accepted as demonstrating the occurrence of the tri­-carboxylic acid cycle. The final decrease of CO 2 output in oxygen appeared not to be related to the occurrence of ‘blocks’ either between citrate and α -ketoglutarate or of pyruvate or α -ketoglutarate oxidases; the inhibition might be due to a shortage of sugar phosphate substrates, caused possibly by oxygen inhibition of cytochrome- c reductase. The outburst of CO 2 , which occurred in potatoes first held in oxygen and then returned to air, could not be attributed solely to oxidation of accumulated citrate.

scholarly journals IN VITRO EFFECTS OF FLUORIDE ON TRICARBOXYLIC ACID CYCLE DEHYDROGENASES AND OXIDATIVE PHOSPHORYLATION: PART I

1967 ◽  
Vol 15 (4) ◽  
pp. 195-201 ◽  
Author(s):  
C. JAMES LOVELACE ◽  
GENE W. MILLER
Keyword(s):  
Oxidative Phosphorylation ◽  
Competitive Inhibition ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Initial Increase ◽  
Acid Cycle ◽  
Oxidase System ◽  
Vitro Effect

Studies were conducted on the in vitro effect of fluoride on the succinic oxidase system utilizing mitochondria obtained from cauliflower. Preincubation of mitochondria with fluoride did not increase inhibition of succinic oxidase. Various other tricarboxylic acid cycle substrates were used to determine their sensitivity to fluoride; only succinate oxidation was affected. A series of succinate concentrations in the presence and in the absence of fluoride showed increased activity of succinic dehydrogenase, which indicated competitive inhibition. Various concentrations of phosphate in the absence of fluoride showed that phosphate had only slight effects on the succinic 2,6-dichlorophenolindophenol reductase component of the succinic oxidase system. In the absence of phosphate, various concentrations of fluoride showed an initial increase in activity followed by a decrease in activity of succinic 2,6-dichlorophenolindophenol reductase. In the presence of phosphate, fluoride caused marked inhibition of succinic 2,6-dichlorophenolindophenol reductase. It is believed that this inhibition results from an enzyme-fluorophosphate complex which has a lower dissociation constant than that of the enzyme-substrate complex. An oxidative phosphorylation study indicated that both respiration and phosphorylation were inhibited.

Studies in the respiratory and carbohydrate metabolism of plant tissues I. Experimental studies of the formation of carbon dioxide, lactic acid and other products in potato tubers under anaerobic conditions

1952 ◽  
Vol 140 (900) ◽  
pp. 362-385 ◽  
Keyword(s):  
Lactic Acid ◽  
Soluble Fraction ◽  
Sugar Content ◽  
Experimental Studies ◽  
Complex Form ◽  
Zinc Salt ◽  
Potato Tubers ◽  
Anaerobic Conditions ◽  
Minimal Rate ◽  
Rate Of Accumulation

Using mature potatoes of low sugar content, held at 10°C both in air and in nitrogen, the following metabolic changes were determined. The CO 2 production in nitrogen showed a complex form, the initial phase consisting of a slight increase, followed by a marked fall to a minimal rate after from 6 to 9 days. The sucrose and hexose content changed little in air, but in nitrogen sucrose decreased markedly, and the hexoses were either stable or increased. While lactic acid accumulated progressively under anaerobic conditions, the content of alcohol did not begin to increase until after about 7 days. Subsequently the rate of accumulation of lactic acid decreased, and that of alcohol increased. During the period of rising lactic acid, an approximately equivalent increase occurred in a non-sugar, non-lactic, alcohol-soluble fraction. Lactic acid was isolated as the zinc salt; it was present mainly as the L-isomer. The experimental data are analyzed in part II of this communication (p. 385).

AN ANOMALOUS TRICARBOXYLIC ACID CYCLE IN ACETOBACTER MELANOGENUM

1960 ◽  
Vol 38 (3) ◽  
pp. 193-203 ◽  
Author(s):  
D. H. Bone ◽  
R. M. Hochster
Keyword(s):  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Oxidase System ◽  
Isocitric Dehydrogenase ◽  
Highly Active ◽  
Carbon Compounds ◽  
Condensing Enzyme

Extracts of gluconate-grown Acetobacter melanogenum contain condensing enzyme and DPN-isocitric dehydrogenase of low specific activity. No evidence could be found for the presence of phosphotransacetylase, aconitase, or TPN-isocitric dehydrogenase. Since the organism or its extracts cannot synthesize the necessary four carbon compounds from pyruvate and from acetate, it is concluded that the tricarboxylic acid cycle does not function in extracts of this organism in the usually accepted manner.The pyruvic oxidase system was found to be highly active, acetaldehyde being the chief intermediate and acetate the end product. The mechanism for the slow incorporation of acetate into other cell constituents is, at present, unknown.

Studies in the respiratory and carbohydrate metabolism of plant tissues - Experimental studies of the formation of carbon dioxide and of the changes in lactic acid, sucrose and in certain fractions of keto-acids in potato tubers in air following anaerobic conditions

1953 ◽  
Vol 141 (904) ◽  
pp. 321-337 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Pyruvic Acid ◽  
Experimental Studies ◽  
Krebs Cycle ◽  
Plant Tissues ◽  
Potato Tubers ◽  
Anaerobic Conditions ◽  
Co2 Output ◽  
Keto Acids

Barker A Saifl (1953 b ), suggested that the initial rapid increase and the subsequent slower decrease in the CO 2 output of potatoes in air after a peroid under anaerobic conditions might be partly related to a quick formation of pyruvic acid from the accumulated lactic acid and to the respiration of the Pyruvic acid via krebs cycle (krebs & johnson 1937; krebs 1952). Information bearing on the associated changes in pyruvic and α-ketoglutaric acid has now been obtained using a technique (Friedemann & Haugen 1943; Friedemann 1950) which while not fully specific gives values that are known to include true pyruvic acid and true α-ketoglutaric acid as well as non-pyruvic and non-α-ketoglutaric acid material respectively. Associated with the loss of Lactic acid in air after nitrogen and the accompanying increase followed by a decrease in the CO 2 output, Mentioned above, there was first a rapid increase in the content of 'pyruvic' and 'α-ketoglutaric acid' and then a prolonged decrease in these fractions. The analysis of the interrelation between the loss of lactic acid and the production of CO 2 and of the keto-acids, and between the changes in the rate of CO2 output and the changes in the concentration of the keto-acids and of sucrose, is taken up in the next paper in this series (Barker & Mapson 1953).

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