| Autor: |
Nagai Kazuo, Wachi Masaaki, Hirasawa Takashi |
| Jazyk: |
angličtina |
| Rok vydání: |
2001 |
| Předmět: |
|
| Zdroj: |
BMC Biotechnology, Vol 1, Iss 1, p 9 (2001) |
| Druh dokumentu: |
article |
| ISSN: |
1472-6750 |
| DOI: |
10.1186/1472-6750-1-9 |
| Popis: |
Abstract Background A non-pathogenic species of coryneform bacteria, Corynebacterium glutamicum, was originally isolated as an L-glutamate producing bacterium and is now used for fermentative production of various amino acids. A mutation in the C. glutamicum ltsA gene caused susceptibility to lysozyme, temperature-sensitive growth, and L-glutamate production. Results The characteristics of eight lysozyme-sensitive mutants which had been isolated after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis were examined. Complementation analysis with the cloned wild-type ltsA gene and DNA sequencing of the ItsA region revealed that four mutants had a mutation in the ltsA gene. Among them, two mutants showed temperature-sensitive growth and overproduced L-glutamate at higher temperatures, as well as the previously reported ltsA mutant. Other two showed temperature-resistant growth: one missense mutant produced L-glutamate to some extent but the other nonsense mutant did not. These two mutants remained temperature-resistant in spite of introduction of ltsA::kan mutation that causes temperature-sensitive growth in the wild-type background. Conclusions These results indicate that a defect caused by the ltsA mutations is responsible for temperature-sensitive growth and L-glutamate overproduction by C. glutamicum. The two temperature-resistant mutants seem to carry suppressor mutations that rendered cells temperature-resistance and abolished L-glutamate overproduction. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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