Direct biosynthesis of poly(3-hydroxyalkanoates) bearing epoxide groups.
The biosynthesis of poly(3-hydroxyalkanoates) (PHAs) by Pseudomonas cichorii YN2 cultured with C6-C12 1-alkenes was studied. PHAs containing repeating units with terminal epoxide groups were obtained when C7-C12 1-alkenes were fed separately as the only carbon source, but no epoxidized unit was detected when 1-hexene was fed. The content of epoxidized units in the polymers was in the range of 4-20 mol%, which was not dependent on the C atom length of the 1-alkene used as a substrate. The polymers produced undergo a glass transition at around -40 degrees C, and number average molecular weights were in the range of 150000-200000 as determined by GPC relative to polystyrene, with M(w)/M(n) ratios of 1.9-2.5. As an intermediate, the corresponding 1,2-epoxyalkane was found in the culture medium. According to this result, the epoxidation of the 1-alkene is the initial step in the synthetic pathway of the epoxy unit in the polymer.
Imamura
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Canon Research Center, 5-1, Morinosato-Wakamiya, Atsugi-shi, 243-0193, Kanagawa, Japan. imamura.takeshi@canon.co.jp
Kenmoku
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Honma
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Kobayashi
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Yano
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D000475:Alkenes / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry*; D005227:Fatty Acids / Q000096:biosynthesis* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism*; D011137:Polystyrenes / Q000737:chemistry; D011549:Pseudomonas / Q000737:chemistry* / Q000378:metabolism
D000475:Alkenes; D004852:Epoxy Compounds; D005227:Fatty Acids; D011091:Polyesters; D011137:Polystyrenes