Polystyrene-colonizing bacteria are enriched for long-chain alkane degradation pathways.

Area of Science:

• Microbiology
• Environmental Science
• Genomics

Background:

• Microbial biodegradation offers a promising solution for plastic waste management.
• Efficient plastic-degrading microbes, particularly for polystyrene (PS), are scarce.
• Genomics provides a powerful approach to discover environmental microbes with plastic-degrading capabilities.

Purpose of the Study:

• To analyze the microbiome of polystyrene samples from diverse Taiwanese environments.
• To identify microbial communities and genetic properties associated with growth on PS surfaces.
• To explore the potential of specific genes, like alkane hydroxylases, in PS biodegradation.

Main Methods:

• 16S rRNA sequencing was employed to characterize microbial communities on PS samples.
• Phylum enrichment analysis identified dominant bacterial groups colonizing PS.
• Functional enrichment analysis of PS-associated species' genomes was performed.

Main Results:

• Cyanobacteria and Deinococcus-Thermus phyla were significantly enriched on PS surfaces.
• These phyla contain species adapted to extreme environments, potentially possessing unique enzymes for PS colonization.
• Genes involved in carbon metabolism, particularly hydrocarbon degradation, and long-chain alkane hydroxylases (e.g., AlmA) were prevalent in PS-associated bacteria.

Conclusions:

• Polystyrene surfaces support distinct microbial communities compared to surrounding soil.
• The prevalence of alkane hydroxylases suggests a role in conferring growth advantages for microbes on PS.
• This study highlights potential microbial candidates and genetic mechanisms for enhanced polystyrene biodegradation.