Record Details
The role of some of the Krebs Cycle reactions in the biosynthetic functions of Thiobacillus thioparus
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The role of some of the Krebs Cycle reactions in the biosynthetic functions of Thiobacillus thioparus |
| Names |
Still, Gerald G., 1933-
(creator) Wang, Chih H. (advisor) |
| Date Issued | 1965-05-14 (iso8601) |
| Note | Graduation date: 1965 |
| Abstract | Aseptic radiorespirometry has been used to examine the utilization of external carbon sources by proliferating Thiobacillus thioparus cells. These studies reveal that glucose, galactose, mannose, fructose, ribose, DL-glutamate, and L-aspartate were not utilized by this chemoautotrophic organism. However, it has been shown that trace amounts of acetate, glycine, DL-serine, DL-alanine, succinate and fumarate can be utilized by T. thioparus cells. To elucidate the nature of the biosynthetic pathways operative in this bacteria, proliferating cell cultures were allowed to metabolize specifically ¹⁴C labeled substrates. The resulting ¹⁴C labeled cells were subsequently hydrolyzed, their amino acids isolated and subjected to degradation experiments. Examination of the respective fates of the label in DL-alanine-2 -¹⁴C, acetate-1-¹⁴C, or acetate-2-¹⁴C in the cellular metabolism revealed that the Krebs Cycle pathway is not functioning as a respiratory mechanism in T. thioparus. However, most of the reactions of the Krebs Cycle pathway are involved in the biosynthesis of carbon skeletons for various amino acids. A CO₂ fixation pathway of the C₃+C₁ type is instrumental in providing C₄ dicarboxylic acids and those amino acids derived therefrom. Acetate can be incorporated into α-ketoglutarate and those amino acids derived therefrom, but cannot be incorporated into the C₄ dicarboxylic acids. It appears that the absence of the enzyme α-ketoglutaric acid oxidase complex accounts for the lack of operation of the Krebs Cycle pathway as the terminal respiratory mechanism. These findings also suggest that the Glyoxylate Cycle pathway is inoperative in this organism. |
| Genre | Thesis/Dissertation |
| Topic | Autotrophic bacteria |
| Identifier | http://hdl.handle.net/1957/47862 |
