Sentence:  <WSD>Plastics</WSD> are energy-rich substances, which is why many of them burn so readily. Any organism that could unlock and use that energy would do well in the Anthropocene. Terrestrial bacteria and fungi which can manage this trick are already familiar to experts in the field. Dr Mincer and Dr Amaral-Zettler found evidence of them on their marine <WSD>plastic</WSD>, too. 
Meaning of the word marked with <WSD> tags:  A synthetic, solid, hydrocarbon-based polymer, whether thermoplastic or thermosetting.