Osamu HIRUTA
Department Kumamoto Health Science University , Kumamoto Health Science University Graduate School Division of Health Sciences, Graduate School of Health Sciences Position |
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Language | English |
Publication Date | 1998 |
Type | |
Peer Review | Peer reviewed |
Title | Enzymatic degradation of poly(hydroxyalkanoate) by Corynebacterium aquaticum IM-1 isolated from activated sludge |
Contribution Type | |
Journal | Polymer Degradation and Stability |
Journal Type | Another Country |
Volume, Issue, Page | 61(2) |
Author and coauthor | Masako Ito, Yuji Saito, Toshio Matsunobu, Osamu Hiruta, Hidehi Takebe |
Details | Poly(4-hydroxybutyric acid)-degrading bacteria were isolated from activated sludge. One strain was selected, which was identified as Corynebacterium aquaticum. The strain C. aquaticum IM-1 excreted an extracellular poly(hydroxyalkanoate) [PHA]depolymerase and grew on 4-hydroxybutyric acid as the sole carbon source. The molecular weight of the purified PHA depolymerase was determined as approximately 33000 Da by SDS-PAGE. The optimum activity of the depolymerase was observed at pH 6.5 and 40 °C. and N-terminal sequences of the depolymerase were not applicable to the well-known enzymes. The enzymatic degradation of polyesters was studied by the erosion rate of solution-cast films of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and poly(ω-hydroxyalkanoate) of different chain lengths (C3–C6). The water-soluble products of poly(3-hydroxybutyrateco-97mol%4-hydroxybutyrate) film were revealed by 1H NMR and FAB-MS analysis, and the main product was the dimer of 4-hydroxybutyric acid. |