scholarly journals STUDIES ON THE METABOLISM OF AUTOTROPHIC BACTERIA

1942 ◽  
Vol 26 (1) ◽  
pp. 89-102 ◽  
Author(s):  
K. G. Vogler ◽  
G. A. LePage ◽  
W. W. Umbreit

The data of this paper indicate that: 1. The "energy of activation" (µ) of sulfur oxidation by the autotrophic bacterium, Thiobacillus thiooxidans, is similar to that of other respirations. 2. The pH of the menstruum does not influence the respiration on sulfur between the limits of pH 2 to 4.8 once contact between the bacterial cell and the sulfur particle has been established but it does influence the rate at which such contact occurs. 3. The pO2 has little effect upon the respiration of this organism. 4. Most organic materials have no detectable effect upon the respiration of Thiobacillus thiooxidans, but the organic acids of terminal respiration seem to stimulate the respiration in the absence of oxidizable sulfur and certain of them inhibit sulfur oxidation. 5. In so far as inhibitor studies on intact cells are trustworthy, sulfur oxidation goes through iron-containing systems similar to cytochrome. It is possible that the oxygen contained in the sulfuric acid formed during sulfur oxidation is derived from the oxygen of the water.

1942 ◽  
Vol 25 (4) ◽  
pp. 617-622 ◽  
Author(s):  
K. G. Vogler

It is shown that there exists in the autotrophic bacterium Thiobacillus thiooxidans a measurable oxygen uptake in the absence of the specific nutrient (sulfur). This respiration is shown to be due to the utilization of organic materials which must have been previously synthesized by the chemosynthetic process, providing evidence that autotrophic bacteria contain a dissimilatory process which involves the breakdown of organic materials and furnishes energy for the maintenance of the cell during periods in which the specific nutrient is absent. This is entirely in accord with the work of Bömeke (1939), who provided similar types of proof for Nitrosomonas and Nitrobacter. One may conclude, therefore, that autotrophic bacteria possess an endogenous respiration which involves the utilization of previously synthesized organic materials.


1942 ◽  
Vol 26 (2) ◽  
pp. 157-168 ◽  
Author(s):  
K. G. Vogler ◽  
W. W. Umbreit

In the autotrophic bacterium, Thiobacillus thiooxidans, the oxidation of sulfur is coupled to transfers of phosphate from the medium to the cells. CO2 fixation is coupled to transfers of inorganic phosphate from the cells to the medium and is dependent, in the absence of concomitant sulfur oxidation, upon the amount of phosphate previously taken up during sulfur oxidation. The energy reservoir, which is formed by sulfur oxidation in the absence of CO2 and which can be released for the fixation of CO2 under conditions which do not permit sulfur oxidation, is a phosphorylated compound and the data suggest that the energy is stored in the cell as phosphate bond energy. It is possible to oxidize sulfur at a constant rate for hours in the absence of CO2. The phosphate energy formed during this process is probably released by cell phosphotases. It is possible to inhibit these phosphotases by means of inorganic phosphate and thus to inhibit sulfur oxidation in the absence of CO2. In the presence of CO2, where alternative uses for the phosphate energy are available, the inhibition is relieved. Sulfur oxidation (energy input) is coupled, not to CO2 fixation, but to phosphate esterification. CO2 fixation (energy utilization) is coupled with phosphate release.


1942 ◽  
Vol 26 (1) ◽  
pp. 103-117 ◽  
Author(s):  
K. G. Vogler

In a study of chemosynthesis (the fixation of CO2 by autotrophic bacteria in the dark) in Thiobacillus thiooxidans, the data obtained support the following conclusions: 1. CO2 can be fixed by "resting cells" of Thiobacillus thiooxidans; the fixation is not "growth bound." 2. The physiological condition of the cell is of considerable importance in determining CO2 fixation. 3. CO2 fixation can occur in the absence of oxidizable sulfur in "young" cells. The extent of this fixation appears to be dependent upon the pCO2. 4. CO2 fixation can also occur under anaerobic conditions and the presence of sulfur does not influence such fixation. 5. However, in the CO2 fixation by cells in the absence of sulfur, only a limited amount of CO2 can be fixed. This amount is approximately 40 µl. CO2 per 100 micrograms bacterial nitrogen. After a culture has utilized this amount of CO2 it no longer has the ability to fix CO2 but releases it during its respiration. 6. Relatively short periods of sulfur oxidation can restore the ability of cells to fix CO2 under conditions where sulfur oxidation is prevented. 7. It is possible to oxidize sulfur in the absence of CO2 and to store the energy thus formed within the cell. It is then possible to use this energy at a later time for the fixation of CO2 in the entire absence of sulfur oxidation. 8. Cultures of Thiobacillus thiooxidans respiring on sulfur utilize CO2 in a reaction which proceeds to a zero concentration of CO2 in the atmosphere. 9. CO2 may act as an oxidizing agent for sulfur. 10. Hydrogen is not utilized by the organism. 11. It is possible to selectively inhibit sulfur oxidation and CO2 fixation.


2001 ◽  
Vol 47 (4) ◽  
pp. 348-358 ◽  
Author(s):  
Rosemarie Jefferey Y Masau ◽  
Jae Key Oh ◽  
Isamu Suzuki

Thiobacillus thiooxidans was grown at pH 5 on thiosulfate as an energy source, and the mechanism of oxidation of inorganic sulfur compounds was studied by the effect of inhibitors, stoichiometries of oxygen consumption and sulfur, sulfite, or tetrathionate accumulation, and cytochrome reduction by substrates. Both intact cells and cell-free extracts were used in the study. The results are consistent with the pathway with sulfur and sulfite as the key intermediates. Thiosulfate was oxidized after cleavage to sulfur and sulfite as intermediates at pH 5, the optimal growth pH on thiosulfate, but after initial condensation to tetrathionate at pH 2.3 where the organism failed to grow. N-Ethylmaleimide (NEM) inhibited sulfur oxidation directly and the oxidation of thiosulfate or tetrathionate indirectly. It did not inhibit the sulfite oxidation by cells, but inhibited any reduction of cell cytochromes by sulfur, thiosulfate, tetrathionate, and sulfite. NEM probably binds sulfhydryl groups, which are possibly essential in supplying electrons to initiate sulfur oxidation. 2-Heptyl-4-hydroxy-quinoline N-oxide (HQNO) inhibited the oxidation of sulfite directly and that of sulfur, thiosulfate, and tetrathionate indirectly. Uncouplers, carbonyl cyanide-m-chlorophenylhydrazone (CCCP) and 2,4-dinitrophenol (DNP), inhibited sulfite oxidation by cells, but not the oxidation by extracts, while HQNO inhibited both. It is proposed that HQNO inhibits the oxidation of sulfite at the cytochrome b site both in cells and extracts, but uncouplers inhibit the oxidation in cells only by collapsing the energized state of cells, ΔµH+, required either for electron transfer from cytochrome c to b or for sulfite binding.Key words: Thiobacillus thiooxidans, thiosulfate, oxidation, sulfite.


1972 ◽  
Vol 18 (12) ◽  
pp. 1907-1913 ◽  
Author(s):  
Kei Amemiya

Many obligate autotrophic bacteria can be grown on glucose using a dialysis flow-through system. Methanomonas methanooxidans, an obligate methylotroph, exhibits many of the properties of an obligate autotrophic bacterium but we have been unable to grow it on glucose using dialysis. In the obligate autotrophic bacteria, the dialysis procedure seems to be removing a toxic product of glucose metabolism but this does not seem to be the case with the methylotroph. Enzymatic assays on a cell-free extract from methane-grown or methane plus glucose-grown cells showed only phosphoglucoisomerase activity, while glucokinase and glucose-6-phosphate dehydrogenase activity were not detected. Studies with resting cells showed that glucose was not oxidized, although the phosphate esters of glucose, fructose, ribose, and gluconate were oxidized. CO2 fixation occurred only in the presence of glucose-6-phosphate. The rate of oxygen consumed and CO2 fixed on glucose-6-phosphate were almost identical with that when methanol was used as the substrate. When the phosphate esters of glucose, fructose, and ribose were used as the sole energy source, only glucose-6-phosphate supported growth to any extent; in fact, the amount of growth was essentially the same as that obtained with methanol. The results from this study suggest that the inability of this organism to grow on glucose may be due to the absence of adequate glucokinase.


2020 ◽  
pp. 1-11
Author(s):  
Patrícia Moisés Urias ◽  
Luis Henrique dos Reis Menêzes ◽  
Vicelma Luiz Cardoso ◽  
Miriam Maria de Resende ◽  
Juliana de Souza Ferreira

1997 ◽  
Vol 48 (4) ◽  
pp. 497 ◽  
Author(s):  
Sholeh ◽  
Rod D. B. Lefroy ◽  
Graeme J. Blair

Elemental sulfur (S) has many attractions as a fertiliser but it must be oxidised to sulfate before it is plant available. Two laboratory incubation experiments with a high S sorbing basaltic soil (Haplohumult) from Walcha, New South Wales, are reported here. The first experiment was conducted to study the effect of ? P and other nutrients on the oxidation of elemental S and the growth of Thiobacillus thiooxidans. The second experiment studied the effect of phosphorus (P) rate, elemental S particle size, and elemental S form on the oxidation of elemental S at different times. There were significant differences between treatments in the percentage and amount of elemental S oxidised, with the lowest oxidation occurring during the 6-week incubation in the P treatment, which represented 1�8% of the applied S compared with 16�0% when all nutrients were supplied. There was a significant linear relationship between T. thiooxidans population at the end of the incubation period and the amount of elemental S oxidised. The oxidation of elemental S was higher when fine (50?150 �m) particle size elemental S was used, compared with coarse (150?250 �m) elemental S. There was no clear difference in oxidation rate between ground and recrystallised elemental S. The S oxidation rates recorded in these experiments were compared with those predicted by an S oxidation model and found to be in close agreement.


1942 ◽  
Vol 43 (2) ◽  
pp. 141-148 ◽  
Author(s):  
W. W. Umbreit ◽  
H. R. Vogel ◽  
K. G. Vogler

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