A Deep-Sea Bacterium Is Capable of Degrading Polyurethane

Area of Science:

• Marine microbiology
• Environmental science
• Biotechnology

Background:

• Plastic waste is a persistent marine contaminant.
• The plastic-degrading capabilities of deep-sea microorganisms are largely unknown.
• Microbial degradation offers an eco-friendly alternative to current plastic waste management.

Purpose of the Study:

• To investigate the potential of deep-sea microorganisms for plastic degradation.
• To identify specific enzymes involved in plastic breakdown by deep-sea bacteria.
• To evaluate the application potential of identified enzymes for plastic waste remediation.

Main Methods:

• Isolation and identification of deep-sea bacteria with plastic-degrading abilities.
• Transcriptomic analysis to identify upregulated genes in response to plastic exposure.
• Liquid chromatography-mass spectrometry (LC-MS) and Fourier transform infrared (FTIR) analysis to identify key enzymes.
• In vitro expression and degradation assays to confirm enzyme function.

Main Results:

• A deep-sea bacterium, Bacillus velezensis GUIA, demonstrated the ability to degrade waterborne polyurethane.
• Transcriptomic analysis revealed upregulation of genes encoding lipase, protease, and oxidoreductase.
• Oxidoreductase Oxr-1 was identified as the key enzyme responsible for degrading both polyurethane and polybutylene adipate terephthalate (PBAT) film.
• The enzyme Oxr-1 showed broad applicability in degrading different types of plastic films.

Conclusions:

• Deep-sea microorganisms possess plastic degradation capabilities.
• Bacillus velezensis GUIA and its enzyme Oxr-1 are promising candidates for developing bio-products for plastic waste management.
• This research opens new avenues for understanding the deep-sea carbon cycle influenced by plastic degradation.