• Korean Journal of Microbiology
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• v.41 no.2
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• pp.140-145
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• 2005

Streptomyces natalensis ATCC27448 produces natamycin, a commercially important macrolide antifungal antibiotic. For molecular genetic study of S. natalensis, we have developed a system for introducing DNA into S. natalensis via conjugal transfer from Escherichia coli. An effective transformation procedure for S. natalensis was established based on transconjugation from E, coli ET12567/pUZ8002 using a ${\Phi}C31$-derived integration vector, pSET152, containing oriT and attP fragments. The high frequency was obtained on MS medium containing 10 mM $MgCl_2$ using $6.25\times10^8$ of E.coli donor cells without heat treatment of spores. In addition, southern blot analysis of exconjugants and the sequence of plasmids containing DNA flanking the insertion sites from the chromosome revealed that S. natalensis contains a single ${\Phi}C31$ attB site and at least a secondary or pseudo attB site. Similar to the case of various Streptomyces species, a single ${\Phi}C31$ attB site of S. natalensis is present within an ORF encoding a pirin-homolog, but a pseudo-attB site is present within a distinct site (GenBank accession no. $YP\_117731$) and also its sequence deviates from the consensus sequences of attB sequence.

• Journal of Life Science
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• v.14 no.2
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• pp.225-228
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• 2004

Natamycin, produced by Streptomyces natalensis ATCC27448, is a polyene macrolide antibiotic, is widely used in the food industry in order to prevent mould contamination. This study carried out to develop an efficient purification process of natamycin from fermentation broth. The stability of natamycin in fermentation broth during storage period was investigated at 4$^{\circ}C$ and room temperature. After the storage of fermentation broth for 14 days at 4$^{\circ}C$, residual activity of natamycin was about 80% but decreased by 27% at room temperature. As solvent to extract natamycin from fermentation broth, methanol was the most efficient. A developed purification procedure includes methanol extraction and Diaion HP-20 column chromatography. Approximately 2.9 g of natamycin was obtained with a final yield of 69.1% and purity of 96.6% from 1.8 l of fermentation broth by this developed purification procedure.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.204.3-204
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• 2005