A variety of culture-based assays confirm the microbial degradation of heterochain, but not homochain, plastic polymersA variety of culture-based assays confirm the microbial degradation of heterochain, but not homochain, plastic polymers

For most plastics, their biological degradation is unproven, unless first exposed to extended periods of elevated temperature or UV light. To validate that a microbe is capable of plastic-degradation, the following criteria should be met: (i) observation of polymer weight loss which significantly exceeds that of the plastics additive content, and/or (ii) clearance zone formation around microbes cultured on plastic-infused media. We investigated the potential these techniques have when assessing both homo- and heterochain polymer degradation. With these methods, we were able to confirm clearance zones in polylactic acid (PLA)-infused agar within the first seven days of incubation with Parengyodontium album, leading to roughly 50 % plastic film weight loss after 28 days. We assembled and scanned the genome of Parengyodontium album to uncover the components of the genome that were responsible for the observed plastic biodegradation.