Poly-β-hydroxybutyrate (PHB) Depolymerase from Fusarium solani Thom
| Autor: | Srividya Shivakumar |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Journal of Chemistry, Vol 2013 (2013) |
| Druh dokumentu: | article |
| ISSN: | 2090-9063 2090-9071 |
| DOI: | 10.1155/2013/406386 |
| Popis: | Fusarium solani Thom produced maximum PHB depolymerase by 48 h when grown in BHM containing 0.2%, w/v PHB, pH 8.0 at 25°C. Statistical optimization studies using Plackett Burman design of PHB depolymerase production yielded maximum PHB depolymerase activity after 2 days as against 4 days in the unoptimized conditions with a 2-fold increase in activity. Partial purification of the extracellular poly-β-hydroxybutyrate (PHB) depolymerase PHAZFus from F. solani Thom by two steps using ammonium sulphate (80% saturation) and affinity chromatography using concanavalin-A yielded 162.3-fold purity and 63% recovery of protein. The enzyme composed of a single polypeptide chain of 85 KDa, as determined by SDS-PAGE. The enzyme stained positive for glycoprotein by PAS staining. Optimum enzyme activity was detected at pH 7.0 and 55°C. The enzyme was stable at pH 7.0 and 55°C for 24 h with a residual activity of almost 85%. Paper chromatography revealed β-hydroxybutyrate monomer as the major end product of PHB hydrolysis. Complete inhibition of the enzyme by 1 mM HgCl2 (100%) indicated the importance of essential disulfide bonds (cystine residues) for enzyme activity or probably for maintaining the native enzyme structure. |
| Databáze: | Directory of Open Access Journals |
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