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

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.