Targeted disruption of homoserine dehydrogenase gene and its effect on cephamycin C production in Streptomyces clavuligerus

2008-01-01
Yilmaz, Ebru I.
Caydasi, Ayse K.
Özcengiz, Gülay
The aspartate pathway of Streptomyces clavuligerus is an important primary metabolic pathway which provides substrates for beta-lactam synthesis. In this study, the hom gene which encodes homoserine dehydrogenase was cloned from the cephamycin C producer S. clavuligerus NRRL 3585 and characterized. The fully sequenced open reading frame encodes 433 amino acids with a deduced M (r) of 44.9 kDa. The gene was heterologously expressed in the auxotroph mutant Escherichia coli CGSC 5075 and the recombinant protein was purified. The cloned gene was used to construct a plasmid containing a hom disruption cassette which was then transformed into S. clavuligerus. A hom mutant of S. clavuligerus was obtained by insertional inactivation via double crossover, and the effect of hom gene disruption on cephamycin C yield was investigated by comparing antibiotic levels in culture broths of this mutant and in the parental strain. Disruption of hom gene resulted in up to 4.3-fold and twofold increases in intracellular free L-lysine concentration and specific cephamycin C production, respectively, during stationary phase in chemically defined medium.

Citation Formats
E. I. Yilmaz, A. K. Caydasi, and G. Özcengiz, “Targeted disruption of homoserine dehydrogenase gene and its effect on cephamycin C production in Streptomyces clavuligerus,” JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY, vol. 35, no. 1, pp. 1–7, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34766.