Homologous expression of aspartokinase (ask) gene in Streptomyces clavuligerus and its hom-deleted mutant: Effects on cephamycin C production

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2010-05-01

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Özcengiz, Gülay
Ünsaldi, Eser
Taşkin, Bilgin
Liras, Paloma
Piret, Jacqueline

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Abstract 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 especially 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.

Subject Keywords

Biotechnology, Applied Microbiology and Biotechnology, Bioengineering

URI

https://hdl.handle.net/11511/39704

Journal

Bioengineered Bugs

DOI

https://doi.org/10.4161/bbug.1.3.11244

Collections

Department of Biology, Article

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Citation Formats

G. Özcengiz, E. Ünsaldi, B. Taşkin, P. Liras, and J. Piret, “Homologous expression of aspartokinase (ask) gene in Streptomyces clavuligerus and its hom-deleted mutant: Effects on cephamycin C production,” Bioengineered Bugs, pp. 191–197, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39704.