دورية أكاديمية
Aromatic amino acid biosynthesis in Alcaligenes eutrophus H16 - II. The isolation and characterization of mutants auxotrophic for phenylalanine and tyrosine.
| العنوان: | Aromatic amino acid biosynthesis in Alcaligenes eutrophus H16 - II. The isolation and characterization of mutants auxotrophic for phenylalanine and tyrosine. |
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| المؤلفون: | Friedrich, B., Schlegel, H.G. |
| المصدر: | Arch. Microbiol. 103, 141-149 (1975) |
| سنة النشر: | 1975 |
| المجموعة: | PuSH - Publikationsserver des Helmholtz Zentrums München |
| مصطلحات موضوعية: | Accumulation Of Prephenic And Chorismic Acid, Alcaligenes Eutrophus H16, Auxotrophic Mutants, Phenylalanine-tyrosine Biosynthesis |
| الوصف: | 1. Mutants derived from the hydrogen bacterium Alcaligenes eutrophus strain H16 auxotrophic for phenylalanine and tyrosine were isolated employing mutagenic agents (EMS, nitrite), the colistine counterselection technique and the "pin-point" isolation method. Three different types of mutants were found: (1) Mutants, requiring phenylalanine or phenylpyruvate for growth, were affected in chorismate mutase as well as prephenate dehydratase. Both activities were regained by reversion to prototrophy. The auxotrophic strains accumulated chorismic acid. (2) Strains with a growth response similar to that of the first group lacked only prephenate dehydratase activity which was partially regained by reversion. Chorismate mutase and prephenate dehydrogenase were derepressed up to two-fold. Mutants grown in minimal medium excreted prephenic acid. (3) The third type of mutants required phenylalanine or phenylpyruvate and grew slowly when supplemented with chorismate or prephenate. The enzymes involved in the specific pathway of phenylalanine and tyrosine were found to be present. Some of them were even more active than in the wild-type. 2. Mutants accumulating chorismic acid or prephenic acid were able to grow on minimal medium when incubated long enough. The chemical instability of the excretion products resulted in their nonenzymatic conversion to subsequent intermediates which were taken up by the cells, allowing growth. 3. A method is described for preparing barium prephenate using the auxotrophic mutant 6B-1 derived from A. eutrophus H16. Prephenic acid, excreted by this strain, was obtained from the culture filtrate with a purity of at least 70% and a yield of approximately 180 mg per 2 l of medium. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| تدمد: | 0302-8933 0003-9276 1432-072X |
| العلاقة: | info:eu-repo/semantics/altIdentifier/wos/undefined; info:eu-repo/semantics/altIdentifier/isbn/0302-8933; info:eu-repo/semantics/altIdentifier/pissn/0003-9276; info:eu-repo/semantics/altIdentifier/e; https://push-zb.helmholtz-muenchen.de/frontdoor.php?source_opus=33026Test; urn:isbn:0302-8933; urn:issn:0003-9276; urn:issn:1432-072X |
| DOI: | 10.1007/BF00436341 |
| الإتاحة: | https://doi.org/10.1007/BF00436341Test https://push-zb.helmholtz-muenchen.de/frontdoor.php?source_opus=33026Test |
| حقوق: | info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.75ED24BA |
| قاعدة البيانات: | BASE |
| تدمد: | 03028933 00039276 1432072X |
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| DOI: | 10.1007/BF00436341 |