A Foundation for Advancing Studies of the Biodegradation of Polyethylene Surrogates by Environmental and Model Laboratory Microbes

TL;DR

This study identifies microbes capable of degrading polyethylene-like materials, offering a resource for biodegradation research.

Contribution

The study provides a detailed genetic and biochemical resource of microbes effective in degrading polyethylene surrogates.

Findings

Actinomycetes were the most common microbes isolated for polyethylene surrogate degradation.

Acinetobacter baylyi and Rhodococcus jostii effectively degraded all three polyethylene surrogates.

Genome sequencing of isolates provides a foundation for future biochemical studies.

Abstract

Polyethylene represents a particularly recalcitrant class of plastics that persist for decades in the natural environment when released as the result of failed waste management policies. In this report, we present a detailed survey of microbes with varying abilities to degrade either branched or linear waxy hydrocarbons that serve as a surrogate for the study of polyethylene biodegradation. This analysis includes measurement of the degree of branching for the surrogates. We further monitored the growth of individual isolates as an indication of substrate preference. We sequenced the genomes for each of our isolates that showed significant rates of growth to accommodate future biochemical studies, and provide a general characterisation of each strain. The vast majority of microbes that we isolated and identified as part of this study were Actinomycetes. However, a small selection of gram‐negative microbes were identified that resulted in degradation of the surrogates. Importantly, our results further identified the model microbes
Acinetobacter baylyi
and
Rhodococcus jostii
as strains that were particularly good at degrading all three of the model polyethylene surrogates employed in this study. The results of this study should serve as a detailed genetic and biochemical resource to the research community investigating polyethylene biodegradation.

A polyethylene surrogate sample containing paraffin, polywax and polyethylene was exposed to selected microbes identified in this study. This image shows the surface of this surrogate following a six‐week incubation with
Rhodococcus jostii
.

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