• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.722-725
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• 1999

Filamentation-suppressed recombinant Escherichia coli strain harboring the Alcaligenes latus polyhydroxyalkanoate (PHA) biosynthesis genes and the E. coli ftsZ gene was constructed and cultivated for the production of poly(3-hydroxybutyrate) [P(3HB)] with high concentration and high content. By the pH-stat fed-batch culture of this recombinant E. coli strain XL1-Blue(pJC5), the final cell concentration and P(3HB) concentration obtained in 44.25h were 172.2g cell dry weight/l and 141.9g P(3HB)/l, respectively, resulting in productivity of 3.21g P(3HB)/l-h. More importantly, the P(3HB) content obtained was 82.4 wt %, which was significantly higher than that obtained with the recombinant E. coli harboring only the PHA biosynthesis genes.

• 한국미생물·생명공학회지
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• 제22권6호
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• pp.614-620
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• 1994

The effects of growth temperature and nutritional components on the synthesis of poly-3-hydroxybutyric acid, PHB, by filamentation-suppressed recombinant Escherichia coli XL1-Blue (pSYL107) were studied. After culturing XL1-Blue(pSYL107) for 48 hours in complex medium at 30$\circ$C, 7Al g/l of PHB could be obtained with the PHB content and PHB yield of 82% and 0.371 g PHB/g glucose, respectively. Lower concentration of PHB(3.2 g/l) was obtained when cultu- red at 37$\circ$C, which seemed to be due to the instability of this strain having amplified FtsZ activity. The PHB concentration of 3.75 g/l was obtained after culturing 60 hours in R medium supplemen- ted with 20 g/l glucose at 30$\circ$C, which was more than twice higher than that obtained with XL1-Blue(pSYL105). This suggested that the enhancement of PHB synthesis by suppressing filamenta- tion was more significant in a defined medium than complex medium. PHB synthesis could be further enhanced by supplementing a small amount of various complex nitrogen sources. When 5 g/l of beef extract was added to a defined medium, PHB concentration, PHB content, and PHB yield obtained after 60 hours of cultivation at 30$\circ$C were 7.46 g/l, 86%, and 0.375 g PHB/g glucose,respectively.