Record Details
The utilization of some amino acids by Azotobacter vinelandii
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The utilization of some amino acids by Azotobacter vinelandii |
| Names |
Bilen, Oya Fatma
(creator) Wang, Chih H. (advisor) |
| Date Issued | 1963-08-06 (iso8601) |
| Note | Graduation date: 1964 |
| Abstract | The effects of different nitrogen sources on the primary and secondary pathways of Azotobacter vinelandii cells were studied by means of the radiorespirometric method. C¹⁴ labeled glucose and several key amino acids related to the tricarboxylic acid cycle, such as glutamic acid, aspartic acid, alanine, serine and glycine were used as tracing substrates. It is known that in Azotobacter vinelandii 80 percent of the substrate glucose is catabolized via the Entner-Doudoroff pathway, 20 percent by way of the pentose phosphate path way. Operation of the tricarboxylic acid cycle has also been demonstrated. The present results indicate that the cells grown in different nitrogen sources such as molecular nitrogen, ammonium nitrate, aminoid and nitrate nitrogen metabolized glucose in the same manner without a noticeable change in the catabolic patterns. Azotobacter vinelandii cells utilized the 1 isomer of glutamic acid preferentially to the d isomer. The latter is metabolized only after the 1 isomer is exhausted. The 1 and d isomers of alanine are utilized concurrently and apparently at the same rate. L-aspartic acid was extensively converted to CO₂ whereas the d isomer is not utilized. The 1 and d isomers of serine were both metabolized. Alanine is utilized to a significant extent by resting cells as well as under proliferating conditions; glutamic acid is metabolized to an appreciable extent only under proliferating conditions i.e. in the presence of an energy source. The kinetics of C¹⁴O₂ evolution for Azotobacter vinelandii cells metabolizing specifically labeled glutamic acid, aspartic acid, alanine and glycine revealed two phases of utilization. 1. An initial slow phase which probably reflects an adaptation period; 2. A later phase at a relatively faster rate of utilization. The rates and extents of C¹⁴O₂ production for cells metabolizing labeled glutamic acid, aspartic acid, alanine and serine confirmed the operation of tricarboxylic acid cycle in intact Azotobacter vinelandii cells. |
| Genre | Thesis/Dissertation |
| Topic | Amino acids -- Metabolism |
| Identifier | http://hdl.handle.net/1957/49043 |
