Homologous expression of aspartokinase (ask) gene inStreptomyces clavuligerusand itshom-deleted mutant: Effects on cephamycin C production
| Autor: | Gülay Özcengiz, Sezer Okay, Eser Ünsaldı, Paloma Liras, Bilgin Taşkın, Jacqueline Piret |
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| Rok vydání: | 2010 |
| Předmět: |
Homoserine dehydrogenase
biology Auxotrophy Mutant Gene Dosage Gene Expression Streptomyces clavuligerus Bioengineering biology.organism_classification Applied Microbiology and Biotechnology Gene dosage Streptomyces Culture Media Bacterial Proteins Biochemistry Report Gene expression Homoserine Dehydrogenase Aspartate kinase Aspartate Kinase Cephamycins Sequence Deletion Biotechnology |
| Zdroj: | Bioengineered Bugs. 1:191-197 |
| ISSN: | 1949-1026 1949-1018 |
| DOI: | 10.4161/bbug.1.3.11244 |
| Popis: | In this study, the effect of homologous multiple copies of the ask gene, which encodes aspartokinase catalyzing the first step of the aspartate pathway, on cephamycin C biosynthesis in S. clavuligerus NRRL 3585 and its hom mutant was investigated. The intracellular pool levels of aspartate pathway amino acids accorded well with the Ask activity levels in TB3585 and AK39. When compared with the control strain carrying vector alone without any gene insert, amplification of the ask gene in the wild strain resulted in a maximum of 3.1- and 3.3-fold increase in specific, 1.7- and 1.9-fold increase in volumetric cephamycin C production when grown in trypticase soy broth (TSB) and a modified chemically defined medium (mCDM), respectively. However, expression of multicopy ask gene in a hom-deleted background significantly decreased cephamycin C yields when the cells were grown in either TSB or mCDM, most probably due to physiological disturbance resulting from enzyme overexpression and high copy number plasmid burden in an auxotrophic host, respectively. |
| Databáze: | OpenAIRE |
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