Publication: Purification and Characterization of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Depolymerase from Thermophilic Actinomadura sp. TF1
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Issued Date
2025-07-01
Resource Type
eISSN
29850290
Scopus ID
2-s2.0-105016107643
Journal Title
Science Essence Journal
Volume
41
Issue
2
Start Page
113
End Page
126
Rights Holder(s)
SCOPUS
Bibliographic Citation
Science Essence Journal Vol.41 No.2 (2025) , 113-126
Suggested Citation
Sriyapai T., Chansiri K., Sriyapai P. Purification and Characterization of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Depolymerase from Thermophilic Actinomadura sp. TF1. Science Essence Journal Vol.41 No.2 (2025) , 113-126. 126. Retrieved from: https://hdl.handle.net/20.500.14740/50527
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Abstract
Actinomadura sp. strain TF1, a thermophilic actinomycete bacterium that produces an enzyme capable of degrading the bioplastic copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), was cultured in basal medium under optimized conditions at pH 8, 45 °C, and 0.4% (w/v) PHBV substrate concentration, as previously studied, to achieve the highest production of PHBV depolymerase. The enzyme was purified through 80% (w/v) ammonium sulphate precipitation, dialysis, and Diethylaminoethyl cellulose (DEAE) column chromatography, resulting in a specific activity of 463.7 U/mg protein, 49.9% recovery, and a 2.8-fold purification. The molecular weight of the purified PHBV depolymerase was determined to be 35 kDa by SDS-PAGE. The enzyme exhibited optimal activity at 45 °C and demonstrated thermal stability within the range of 35-45 °C. The optimal pH for activity was 8, with stability observed between pH 8 and 9. PHBV depolymerase displayed strong activity against substrates such as PHBV, polyhydroxybutyrate (PHB), and polybutylene succinate (PBS), with the highest degradation activity observed for PHBV. Additionally, the enzyme hydrolyzed p-nitrophenol esters, confirming its classification as an esterase. The activity of PHBV depolymerase was enhanced by the presence of Ca<sup>2+</sup>, Na<sup>+</sup>, and K<sup>+</sup> ions but was inhibited by Fe<sup>2+</sup>, Mg<sup>2+</sup>, Mn<sup>2+</sup>, Zn<sup>2+</sup>, Cu<sup>2+</sup>, and Hg<sup>2+</sup> ions. Dithiothreitol (DTT) exhibited a significant inhibitory effect. In conclusion, this study is the first to report the purification and characterization of PHBV depolymerase from Actinomadura sp. strain TF1.