| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 681569 | Bioresource Technology | 2012 | 6 Pages |
Cross-linked enzyme aggregates of poly-3-hydroxybutyrate (PHB) depolymerase from Streptomyces exfoliatus (PhaZSex–CLEAs) have been prepared. Acetone was used as the precipitating agent, while addition of bovine serum albumin (BSA) facilitated CLEAs formation. Conditions for enzyme precipitation and cross-linking have been optimized, and confocal scanning microscopy showed a homogeneous enzyme distribution in the biocatalyst. Obtained PhaZSex–CLEAs presented an average size of 50–300 μm, showing a high PHB depolymerase activity of 255 U/g wet biocatalyst at 40 °C and pH 7.0. Temperature-activity profile of PhaZSex–CLEAs at pH 8.0 showed that the highest activity for pNPB hydrolysis was achieved at 60 °C, whereas pH-activity profile at 40 °C indicated that highest activity for PHB hydrolysis was achieved at pH 7.0. Additionally, immobilized biocatalyst could be recycled at least for 20 consecutive batch reactions without loss of catalytic activity, and showed higher pH and temperature stability, and better tolerance to several organic solvents than its soluble counterpart.
► PHB depolymerase from Streptomyces exfoliatus was immobilized as cross-linked enzyme aggregates. ► Improved cross-linked enzyme aggregates with bovine serum albumin were prepared. ► PHB depolymerase activity of 255 U/g wet biocatalyst was obtained at 40 °C and pH 7.0. ► CLEAs could be recycled at least for 20 consecutive reactions without loss of activity. ► CLEAs showed higher stability than the soluble enzyme.
