Valorizing plastic waste by insect consumption

Abstract

Insects first began evolving hundreds of millions of years ago, and aided by gut microbes, they have been consuming hydrocarbon polymers ever since. Few man-made plastic polymers are chemically novel, so it is reasonable that insect/microbe systems can be found or developed to degrade them rapidly. However, remediation of global plastic waste problems should involve more than just conversion into CO2. Some industryscale microbial enzymatic degradation of plastic polymers may yield valuable monomers, but the plastic waste starting material must be of uniform chemistry and clean. This adds cost to the process. Many insect species can be utilized for animal feed as well as human food. Some of these insects have the capability to degrade plastic polymers. However, valorizing plastic wastes by producing edible insects or useful frass has largely been overlooked. Here we assemble the current knowledge of plastic degradation rates by insects. In addition, we also show the first instance of insect degradation of polyurethane and the first identification and isolation of insect gut fungi as directly aiding insect degradation.