| Title | Purification and Characterization of Poly(3-hydroxybutyrate) Depolymerase from a Fungal Isolate, Emericellopsis minima W2 |
|---|---|
| Author | Do Young Kim 1 , Ji Hye Yun 1 , Hyung Woo Kim 2 , Kyung Sook Bae 3 , and Young Ha Rhee 1 * |
| Address | 1 Department of Microbiology, Chungnam National University, Daejeon 305-764, Korea; 2 Institute of Biotechnology, Chungnam National University, Daejeo |
| Bibliography | Journal of Microbiology, 40(2),129-133, 2002, |
| DOI | |
| Key Words | Emericellopsis minima, PHB depolymerase, poly(3-hydroxyalkanoate), poly(3-hydroxybutyrate) |
| Abstract | The fungus, Emericellopsis minima W2, capable of degrading poly(3-hydroxybutyrate) (PHB) was isolated from a waste water sample. Production of the PHB depolymerase from E. minima W2 (PhaZ_Emi ) was significantly repressed in the presence of glucose. PhaZ_Emi was purified by column chromatography on Octyl-Sepharose CL-4B and Sephadex G-100. The molecular mass of the PhaZ_Emi , which consisted of a single polypeptide chain, was estimated to be 48.0 kDa by SDS-PAGE and its pI value was 4.4. The maximum activity of the PhaZ_Emi was observed at pH 9.0 and 55 C. It was significantly inactivated by 1 mM dithiothreitol, 2 mM diisopropyl fluorophosphate, 0.1 mM Tween 80, and 0.1 mM Triton X-100, but insensitive to phenylmethylsulfonyl fluoride and N-ethylmaleimide. The PhaZ_Emi efficiently hydrolyzed PHB and its copolyester with 30 mol% 3-hydroxyvalerate, but did not act on poly(3-hydroxyoctanoate). It also hydrolyzed p-nitrophenylacetate and p-nitrophenylbutyrate but hardly affected the longer-chain forms. The main hydrolysis product of PHB was identified as a dimer of 3-hydroxybutyrate. |
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