Degradation Rates and Bacterial Community Compositions Vary among Commonly Used Bioplastic Materials in a Brackish Marine Environment

Abstract

Plastic pollution threatens both terrestrial and aquatic ecosystems. As a result of the pressures of replacing oilbased materials and reducing the accumulation of litter in the environment, the use of bioplastics is increasing, despite little being known about their accurate biodegradation in natural conditions. Here, we investigated the weight attrition and degradation behavior of four different bioplastic materials compared to conventional oil-based polyethylene during a 1-year in situ incubation in the brackish Baltic Sea and in controlled 1 month biodegradation experiments in the laboratory. Bacterial communities were also investigated to verify whether putative plasticdegrading bacteria are enriched on bioplastics. Poly-L-lactic acid showed no signs of degradation, whereas poly(3-hydroxybutyrate/ 3-hydroxyvalerate) (PHB/HV), plasticized starch (PR), and cellulose acetate (CA) degraded completely or almost completely during 1-year in situ incubations. In accordance, bacterial taxa potentially capable of using complex carbon substrates and belonging, e.g., to class Gammaproteobacteria were significantly enriched on PHB/HV, PR, and CA. An increase in gammaproteobacterial abundance was also observed in the biodegradation experiments. The results show substantial differences in the persistence and biodegradation rates among bioplastics, thus highlighting the need for carefully selecting materials for applications with risk of becoming marine litter.

Life Cycle of Functional All-Green Biocompatible Fibrous Materials Based on Biodegradable Polyhydroxybutyrate and Hemin: Synthesis, Service Life, and the End-of-Life via Biodegradation

“…This process is preceded by the so-called lag phase, when microorganisms need to be adapted to the to-be-degraded polymer. At the first stage of biodegradation, the joint action of extracellular enzymes and abiotic agents and external factors (oxidation, photodegradation, ozonation, and hydrolysis) leads to depolymerization of long-chain polymers and their fragmentation into shorter chain fragments. , Depolymerization is supported by enzymes and free radicals that cleave (chain scission) macromolecular chains down to oligomers, dimers, and monomers. The stage of assimilation involves the formation of new biomass and energy.…”

Functional Redundant Microbiome Enhanced Anaerobic Digestion Efficiency under Ammonium Inhibition Conditions

“…Microorganisms play an important role in global element cycling, agricultural production, pollutant degradation, , and many other processes. Nevertheless, anthropogenic climate change and other challenges pose a serious threat to microbial diversity and ecosystem functions .…”

One-Pot Biosynthesis of Acetone from Waste Poly(hydroxybutyrate)

“…However, to date, little consideration has been given to the fate of PHB after consumer use. PHB degrades in certain natural environments via microbial metabolism, , with approximately 20% of PHB-derived carbon converted into biomass and the remaining 80% released as carbon dioxide (aerobic conditions) or methane (anaerobic conditions) . Inspired by recent studies that upcycle post-consumer petrochemical plastic waste − and motivated to develop technologies to ensure a sustainable future for next-generation plastics, we hypothesized that the propensity of PHB for biodegradation makes it an ideal feedstock for rationally designed biodegradation and recycling systems to produce useful chemicals.…”