scholarly journals Choice between autotrophy and heterotrophy in Pseudomonas oxalaticus. Utilization of oxalate by cells after adaptation from growth on formate to growth on oxalate

1968 ◽  
Vol 107 (5) ◽  
pp. 699-704 ◽  
Author(s):  
Maureen A. Blackmore ◽  
J. R. Quayle ◽  
I O Walker
Keyword(s):  
Carbon Dioxide ◽  
Energy Source ◽  
Dicarboxylic Acids ◽  
Carbon Dioxide Fixation ◽  
Labelling Pattern ◽  
Carboxyl Group ◽  
Isotopic Data ◽  
14Co2 Fixation ◽  
Stages Of Growth ◽  
Autotrophic Metabolism

1. The labelling patterns of phosphoglycerate obtained from formate-grown or oxalate-grown Pseudomonas oxalaticus after exposure for 15sec. to [14C]formate or [14C]oxalate respectively were determined. 2. The phosphoglycerate obtained from the formate-grown cells contained 78% of the radioactivity in the carboxyl group. This is in accord with that predicted for operation of the ribulose diphosphate cycle of carbon dioxide fixation. 3. The labelling pattern of the phosphoglycerate obtained from the oxalate-grown cells approached uniformity, as predicted for the heterotrophic pathway of oxalate assimilation. The departure from complete uniformity may have been due to concurrent 14CO2 fixation into C4 dicarboxylic acids. 4. The labelling pattern of phosphoglycerate obtained from cells that had just started to grow on oxalate after adaptation from formate was determined after incubation of the cells for 15sec. with [14C]oxalate. This pattern approached uniformity. 5. The pathway of incorporation of 14CO2 into cells that had just started to grow on oxalate after adaptation from formate, in the presence of either formate or oxalate as energy source, was studied by chromatographic and radio-autographic analysis. 6. It is concluded from the isotopic data that a mixed heterotrophic–autotrophic metabolism, with the former mode predominating, operates in the initial stages of growth on oxalate after adaptation from growth on formate.

Stomatal Metabolism: Carbon Dioxide Fixation in Attached and Detached Epidermis of Commelina

1978 ◽  
Vol 5 (6) ◽  
pp. 767
Author(s):  
C.M Wilmer ◽  
N Thorpe ◽  
J.C Rutter ◽  
F.L Milthorpe
Keyword(s):  
Carbon Dioxide ◽  
Tca Cycle ◽  
Carbon Dioxide Fixation ◽  
Reverse Direction ◽  
Gaseous Exchange ◽  
14Co2 Fixation ◽  
Fixation Pattern ◽  
The Difference ◽  
Sugar Phosphates ◽  
Tca Cycle Intermediates

Rates of accumulation of radioactivity and the nature of 14CO2 fixation products were measured in mesophyll, attached epidermis and detached epidermis of Commelina cyanea and C. communis. In the illuminated detached epidermis of C. cyanea, most of the fixation products were malate and aspartate (in almost equal proportions), with small amounts of sugars, sugar phosphates, serine, glycine, alanine and TCA cycle intermediates. In that of C. communis there was a smaller proportion of aspartate and a higher proportion of sugars, glutamate and tricarboxylic acids. The much higher rates of accumulation of labelled fixation products in attached epidermis of C. cyanea can in part be attributed to glycine, serine and alanine, which appear to be imported from the mesophyll very shortly after the leaf is first exposed to 14CO2. Over longer periods of time, labelled sugars contributed an appreciable and increasing proportion. In C. communis, after 15-30 min, most of the difference between attached and detached epidermis was attributable to the presence of labelled sugars. The fixation pattern in the mesophyll of these species was typical of C*3-type photosynthesis. Autoradiographs of detached epidermis showed that the label was predominantly in stomata while those of attached epidermis showed more label in stomata than elsewhere after 1 min and they were uniformly labelled after 30 min. These findings suggest that metabolites are translocated from the mesophyll to the epidermis fairly readily. There is probably flow in the reverse direction as well as gaseous exchange of 14C between these tissues.

scholarly journals The C4-dicarboxylic acid pathway of photosynthesis. Identification of intermediates and products and quantitative evidence for the route of carbon flow

1969 ◽  
Vol 114 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Hilary S. Johnson ◽  
M. D. Hatch
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Dicarboxylic Acid ◽  
Dicarboxylic Acids ◽  
Main Flow ◽  
Carbon Flow ◽  
Dihydroxyacetone Phosphate ◽  
Carboxyl Group ◽  
Quantitative Evidence ◽  
Acid Pathway

1. When leaves with the C4-dicarboxylic acid pathway of photosynthesis are exposed to 14CO2 the major labelled compounds formed, in order of labelling, are dicarboxylic acids, 3-phosphoglycerate, bexose phosphates and sucrose. During the present studies several quantitatively minor intermediates were identified and their labelling behaviour is described. 2. The pattern of labelling of dihydroxyacetone phosphate, fructose 1,6-diphosphate and ribulose di- and mono-phosphates during radiotracer pulse–chase experiments was consistent with their operation as intermediates in the pathway of carbon dioxide fixation. 3. Serine, glycine, alanine and glutamate had labelling patterns typical of products secondary to the main flow of carbon. 4. The mechanism of the transfer of label from C-4 of dicarboxylic acids to C-1 of 3-phosphoglycerate was also examined. Evidence consistent with pyruvate being derived from C-1, C-2 and C-3 of oxaloacetate, and for a relationship between ribulose 1,5-diphosphate and the acceptor for the C-4 carboxyl group, was obtained. 5. Evidence is provided that, under steady-state conditions, essentially all the label incorporated from 14CO2 into C-1 of 3 phosphoglycerate enters via C-4 of the dicarboxylic acids. These and other studies indicated that the route via dicarboxylic acids is essentially the sole route for entry of carbon into 3-phosphoglycerate.

scholarly journals BIOSYNTHESIS OF DICARBOXYLIC ACIDS BY CARBON DIOXIDE FIXATION

1950 ◽  
Vol 187 (2) ◽  
pp. 891-905 ◽  
Author(s):  
Seymour. Korkes ◽  
Alice. del Campillo ◽  
Severo. Ochoa
Keyword(s):  
Carbon Dioxide ◽  
Dicarboxylic Acids ◽  
Carbon Dioxide Fixation

scholarly journals BIOSYNTHESIS OF DICARBOXYLIC ACIDS BY CARBON DIOXIDE FIXATION

1950 ◽  
Vol 187 (2) ◽  
pp. 863-874 ◽  
Author(s):  
Severo. Ochoa ◽  
Joao Baptista Veiga Salles ◽  
Priscilla J. Ortiz
Keyword(s):  
Carbon Dioxide ◽  
Dicarboxylic Acids ◽  
Carbon Dioxide Fixation

scholarly journals BIOSYNTHESIS OF DICARBOXYLIC ACIDS BY CARBON DIOXIDE FIXATION

1951 ◽  
Vol 192 (1) ◽  
pp. 301-312 ◽  
Author(s):  
Seymour. Kaufman ◽  
Seymour. Korkes ◽  
Alice. del Campillo
Keyword(s):  
Carbon Dioxide ◽  
Dicarboxylic Acids ◽  
Carbon Dioxide Fixation

scholarly journals BIOSYNTHESIS OF DICARBOXYLIC ACIDS BY CARBON DIOXIDE FIXATION

1950 ◽  
Vol 187 (2) ◽  
pp. 849-861 ◽  
Author(s):  
Joao Baptista Veiga Salles ◽  
Severo. Ochoa
Keyword(s):  
Carbon Dioxide ◽  
Dicarboxylic Acids ◽  
Carbon Dioxide Fixation

scholarly journals BIOSYNTHESIS OF DICARBOXYLIC ACIDS BY CARBON DIOXIDE FIXATION

1948 ◽  
Vol 174 (3) ◽  
pp. 979-1000 ◽  
Author(s):  
Severo. Ochoa ◽  
Alan H. Mehler ◽  
Arthur. Kornberg
Keyword(s):  
Carbon Dioxide ◽  
Dicarboxylic Acids ◽  
Carbon Dioxide Fixation
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