Exploring the polyurethanolytic activity and microbial composition of landfill microbial communities

Area of Science:

• Environmental microbiology
• Biotechnology
• Polymer science

Background:

• Microbial degradation of polyurethanes (PU) is underexplored.
• The influence of microenvironmental conditions on PU-degrading microbial communities remains unclear.
• Understanding these communities is crucial for developing effective PU waste management strategies.

Purpose of the Study:

• To investigate the polyurethanolytic activity and taxonomic composition of landfill-derived microbial communities.
• To determine if microenvironmental conditions affect the biodegradative capacity of these communities.
• To identify potential PU-degrading genera and assess their relationship with specific microhabitats.

Main Methods:

• Enrichment of microbial communities using a polyether-polyurethane-acrylic (PE-PU-A) coating (PolyLack®).
• Fourier-transform infrared (FTIR) spectroscopy to analyze chemical group modifications.
• Enzyme activity assays (esterase, urease).
• Microbial community profiling using 16S rDNA V3 region PCR-DGGE and correspondence analysis.

Main Results:

• All tested landfill microbial communities could grow on PE-PU-A as a sole carbon source, with performance varying among them.
• FTIR analysis confirmed the degradation of ester, urethane, ether, aromatic, aliphatic, and acrylate groups.
• Esterase activity was highest at 5 days, while urease activity increased by 21 days.
• Rhizobiales and Micrococcales predominated; known PU-degraders (e.g., Paracoccus) and potential new degraders (e.g., Advenella) were identified.
• Correspondence analysis revealed distinct community groupings, suggesting microenvironment-driven taxonomic differentiation, with unique OTUs found in high-performing groups.

Conclusions:

• Microenvironmental conditions in landfills significantly shape the taxonomic composition of microbial communities.
• This shaping influences the polyether-polyurethane-acrylic biodegradative capacities of the communities.
• The identified landfill microbial communities are valuable resources for the biological treatment of PU waste and other xenobiotics.