Park, Woo Jin (2022-04). Isolation and Characterization of Polyurethane-Degrading Microorganisms. Master's Thesis. Thesis uri icon


  • Polyester polyurethanes (PUR) are one of most versatile synthetic polymers with various applications. However, tremendous quantities of end-of-life PUR is problematic and has caused negative impacts on the environment and health of ecological systems. Due to their environmental pollution, development of biodegradation technology is needed. In this work, PUR degrading microorganisms were isolated from the sediment in Galveston Bay and local landfill in Texas. One bacterial and two fungal strains degrading PUR were isolated. The bacterium belonged to Pseudomonas sp. and the fungi were identified as Purpureocillium sp. and Coniochaeta sp. The degradation efficiency of culture of Pseudomonas sp. with culture supernatant of Purpureocillium sp. against PUR was recorded to identify their relationship towards degradation for 42 days. An extracellular esterase activity of culture (PGB+PLI) was 12.3 U L-1 on day 22 maintaining 7 times higher activity than that of pure culture. Pits on surface and porous structure of degraded PUR were observed through scanning electron microscopy (SEM). Furthermore, a peak at 1,731 cm-1 corresponding ester linkage decreased most in culture (PGB+PLI). Intensity belonging to degradation product, diethylene glycol (DEG) and adipic acid (AA), was detected higher in culture (PGB+PLI) compared to pure culture, through Gas Chromatography (GC) with Flame Ionization Detection (FID).

publication date

  • April 2022