Project description:Biodegradable plastics are one possible solution for reducing plastic waste, yet the mechanisms and organisms involved in their degradation in the aquatic environment remain understudied. In this study, we have enriched a microbial community from North Sea water and sediment, capable of growing on the polyester poly(butylene succinate). This culture was grown on two other biodegradable polyesters, polycaprolactone and ecovio® FT (a PBAT-based blended biodegradable plastic), and the differences between community structure and activity on these three polymers were determined by metagenomics and metaproteomics. We have seen that the plastic supplied drives the community structure and activity. Setups growing on ecovio® FT were more diverse, yet showed the lowest degradation, while poly(butylene succinate) and polycaprolactone resulted in a less diverse community but much higher degradation efficiencies. The dominating species were Alcanivorax sp., Thalassobius sp., or Pseudomonas sp., depending on the polymer supplied. Furthermore, we have observed that Gammaproteobacteria were more abundant and active within the biofilm and Alphaproteobacteria within the free-living fraction of the enrichments. Two of the three PETase-like enzymes isolated were expressed as tandems (Ple -tan1 &Ple – tan2) and all three were produced by Pseudomonas sp. Of those, Ple-tan1 was most active on all three substrates and also the most thermostable. Overall, we could show that all three plastics investigated can be mineralized by bacteria naturally occurring within the marine environment and characterize some of the enzymes involved in the degradation process.
Project description:Microbial colonization patterns and biodegradation of petrochemical and biodegradable plastics in lake waters: insights from a field experiment
Project description:Although the biodegradation of biodegradable plastics in soil and compost is well-studied, there is little knowledge on the metabolic mechanisms of synthetic polymers degradation by marine microorganisms. Here, we present a multiomics study to elucidate the biodegradation mechanism of a commercial aromatic-aliphatic copolyester film by a marine microbial enrichment culture. The plastic film and each monomer can be used as sole carbon source. Our analysis showed that the consortium synergistically degrades the polymer, different degradation steps being performed by different members of the community. Analysis of gene expression and translation profiles revealed that the relevant degradation processes in the marine consortium are closely related to poly(ethylene terephthalate) biodegradation from terrestrial microbes. Although there are multiple genes and organisms with the potential to perform a degradation step, only a few of these are active during biodegradation. Our results elucidate the potential of marine microorganisms to mineralize biodegradable plastic polymers and describe the mechanisms of labor division within the community to get maximum energetic yield from a complex synthetic substrate.
Project description:Bacterial biofilms colonizing plastics and microplastics in estuarine waters, with an emphasis on Vibrio spp. and their antibacterial resistance