Visualization of Enzymatic Degradation of Poly[(R)-3-hydroxybutyrate] Single Crystals by an Extracellular PHB Depolymerase†

1997 ◽  
Vol 30 (4) ◽  
pp. 833-839 ◽  
Author(s):  
Tadahisa Iwata ◽  
Yoshiharu Doi ◽  
Ken-ichi Kasuya ◽  
Yoshio Inoue
Keyword(s):  
Single Crystals ◽  
Enzymatic Degradation ◽  
Phb Depolymerase ◽  
Extracellular Phb Depolymerase

Enzymatic Degradation of Single Crystals of Bacterial and Synthetic Poly(β-hydroxybutyrate)

1996 ◽  
Vol 29 (7) ◽  
pp. 2472-2478 ◽  
Author(s):  
Philippa J. Hocking ◽  
Robert H. Marchessault ◽  
Mark R. Timmins ◽  
Robert W. Lenz ◽  
R. Clinton Fuller
Keyword(s):  
Single Crystals ◽  
Enzymatic Degradation

Morphology and Enzymatic Degradation of Poly(l-lactic acid) Single Crystals

1998 ◽  
Vol 31 (8) ◽  
pp. 2461-2467 ◽  
Author(s):  
Tadahisa Iwata ◽  
Yoshiharu Doi
Keyword(s):  
Lactic Acid ◽  
Single Crystals ◽  
Enzymatic Degradation

Enzymatic degradation of ?(1 ? 4) xylan single crystals

Biopolymers ◽  
1979 ◽  
Vol 18 (10) ◽  
pp. 2459-2464 ◽  
Author(s):  
H. Chanzy ◽  
J. Comtat ◽  
M. Dube ◽  
R. H. Marchessault
Keyword(s):  
Single Crystals ◽  
Enzymatic Degradation

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.

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