Microbial succession during the degradation of bioplastic in coastal marine sediment favors sulfate reducing microorganisms

Marine environments are sinks for many contaminants, including petroleum-based plastic waste. Bioplastics, or biodegradable plastics derived from renewable resources, considered promising alternatives as numerous studies have demonstrated their degradation in marine environments. However, rates of vary and microbial consortia responsible its not well characterized. Previous research by our group has shown that polyhydroxyalkanoate (PHA) stimulates sulfate reducing microorganisms (SRM), enriches reduction gene pools, accumulates antibiotic metal resistance genes. Here, we quantify the rate PHA pellets sediment present long-term temporal changes PHA-associated SRM communities over 424 days. For comparative purposes, polyethylene terephthalate (PET) ceramic served biofilm controls free-living overlying water column a non-biofilm control. experienced 51% mass loss after days generalized additive mixed model predicted 100% would require 909 Throughout course 424-day exposure, was colonized distinct community while PET were similarly structured communities. comprised larger proportion overall (25 – 40%) biofilms compared to across all timepoints. Further, diversity greater within than biofilms. This study shows degrades relatively slowly promotes shift structure toward reduction, demonstrating ability this manufactured polymer alter environment via disruption biogeochemical cycling, indicating rises level pollutant benthic systems.