scholarly journals Enzymatic Degradation and Adsorption on Solution-Grown Lamellar Crystals of Poly(.BETA.-propiolactone) with an Extracellular PHB Depolymerase.

2001 ◽  
Vol 57 (6) ◽  
pp. 184-190 ◽  
Author(s):  
Yukiko Furuhashi ◽  
Tadahisa Iwata ◽  
Yoshiharu Doi
Keyword(s):  
Enzymatic Degradation ◽  
Phb Depolymerase ◽  
Lamellar Crystals ◽  
Extracellular Phb Depolymerase

scholarly journals Novel Extracellular PHB Depolymerase from Streptomyces ascomycinicus: PHB Copolymers Degradation in Acidic Conditions

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e71699 ◽  
Author(s):  
Javier García-Hidalgo ◽  
Daniel Hormigo ◽  
Miguel Arroyo ◽  
Isabel de la Mata
Keyword(s):  
Phb Depolymerase ◽  
Acidic Conditions ◽  
Extracellular Phb Depolymerase

scholarly journals Production, purification, and kinetics of the poly-β-hydroxybutyrate depolymerase from Microbacterium paraoxydans RZS6: A novel biopolymer-degrading organism isolated from a dumping yard

2019 ◽  
Author(s):  
RZ Sayyed ◽  
SJ Wani ◽  
Abdullah A. Alyousef ◽  
Abdulaziz Alqasim ◽  
Asad Syed
Keyword(s):  
Enzyme Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Scale Up ◽  
Sodium Dodecyl ◽  
Contaminated Site ◽  
Rrna Gene ◽  
Minimal Salt Medium ◽  
Phb Depolymerase ◽  
Microbacterium Paraoxydans ◽  
Extracellular Phb Depolymerase

AbstractPoly-β-hydroxybutyrate (PHB) depolymerase can decompose biodegradable polymers and therefore has great commercial significance in the bioplastic sector. However, few reports have described PHB depolymerases based on isolates obtained from plastic-contaminated sites that reflect the potential of the source organism. In this study, we evaluated Microbacterium paraoxydans RZS6 as a producer of extracellular PHB depolymerase isolated from a plastic-contaminated site in the municipal area of Shahada, Maharashtra, India, for the first time. The isolate was identified using the polyphasic approach, i.e., 16S rRNA gene sequencing, gas chromatographic analysis of fatty acid methyl esters, and BIOLOG identification, and was found to hydrolyze PHB on minimal salt medium containing PHB as the only source of carbon. Both isolates produced PHB depolymerase at 30°C within 2 days and at 45°C within 4 days. The enzyme was purified most efficiently using an octyl-sepharose CL-4B column, with the highest purification yield of 6.675 U/mg/mL. The enzyme required Ce2+ and Mg2+ ions but was inhibited by Fe2+ ions and mercaptoethanol. Moreover, enzyme kinetic analysis revealed that the enzyme was a metalloenzyme requiring Mg2+ ions, with optimum enzyme activity at 45°C (thermophilic) and under neutrophilic conditions (optimum pH = 7). The presence of Fe2+ ions (1 mM) and mercaptoethanol (1000 ppm) completely inhibited the enzyme activity. The molecular weight of the enzyme (40 kDa), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, closely resembled that of PHB depolymerase from Aureobacterium saperdae. Scale-up from the shake-flask level to a laboratory-scale bioreactor further enhanced the enzyme yield. Our findings highlighted the applicability of M. paraoxydans as a producer of extracellular PHB depolymerase isolated from a plastic-contaminated site in the municipal area of Shahada, Maharashtra, India.

scholarly journals Properties of a Novel Intracellular Poly(3-Hydroxybutyrate) Depolymerase with High Specific Activity (PhaZd) in Wautersia eutropha H16

2005 ◽  
Vol 187 (20) ◽  
pp. 6982-6990 ◽  
Author(s):  
Tomoko Abe ◽  
Teruyuki Kobayashi ◽  
Terumi Saito
Keyword(s):  
Catalytic Domain ◽  
Ralstonia Eutropha ◽  
Specific Activity ◽  
High Specific Activity ◽  
Catalytic Triad ◽  
Culture Conditions ◽  
Phb Depolymerase ◽  
Wautersia Eutropha ◽  
Extracellular Phb Depolymerase ◽  
Intracellular Phb Depolymerase

ABSTRACT A novel intracellular poly(3-hydroxybutyrate) (PHB) depolymerase (PhaZd) of Wautersia eutropha (formerly Ralstonia eutropha) H16 which shows similarity with the catalytic domain of the extracellular PHB depolymerase in Ralstonia pickettii T1 was identified. The positions of the catalytic triad (Ser190-Asp266-His330) and oxyanion hole (His108) in the amino acid sequence of PhaZd deduced from the nucleotide sequence roughly accorded with those of the extracellular PHB depolymerase of R. pickettii T1, but a signal peptide, a linker domain, and a substrate binding domain were missing. The PhaZd gene was cloned and the gene product was purified from Escherichia coli. The specific activity of PhaZd toward artificial amorphous PHB granules was significantly greater than that of other known intracellular PHB depolymerase or 3-hydroxybutyrate (3HB) oligomer hydrolases of W. eutropha H16. The enzyme degraded artificial amorphous PHB granules and mainly released various 3-hydroxybutyrate oligomers. PhaZd distributed nearly equally between PHB inclusion bodies and the cytosolic fraction. The amount of PHB was greater in phaZd deletion mutant cells than the wild-type cells under various culture conditions. These results indicate that PhaZd is a novel intracellular PHB depolymerase which participates in the mobilization of PHB in W. eutropha H16 along with other PHB depolymerases.

Crystal Structure, Thermal Behavior and Enzymatic Degradation of Poly(tetramethylene adipate) Solution-Grown Chain-Folded Lamellar Crystals

2004 ◽  
Vol 4 (3) ◽  
pp. 296-307 ◽  
Author(s):  
Tadahisa Iwata ◽  
Shiomi Kobayashi ◽  
Kenji Tabata ◽  
Noriyuki Yonezawa ◽  
Yoshiharu Doi
Keyword(s):  
Crystal Structure ◽  
Thermal Behavior ◽  
Enzymatic Degradation ◽  
Lamellar Crystals
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