Project description:Exoproteomes from the yeast Vishniacozyma dimennae blapla were analyzed in order to identify putative polyesterases responsible for its ability to hydrolyze various biodegradable plastics. To this end, the yeast was grown in a mineral medium and in the presence of different polyesters, like poly(caprolactone), poly(lactic acid), poly(ethylene succinate), poly(butylene succinate) and poly(butylene adipate-co-terephthalate), as well as with pyruvate and glucose as controls. The ultimate goal was to overexpress putative detected polyesterases to find the one responsible for the polyester-hydrolyzing phenotype.
Project description:By screening the secretomes of polymer induced Pseudomonas pseudoalcaligenes we identify a new enzyme PpEst that can degrade the co-aliphatic-aromatic polyester poly(1,4-butylene adipate-co-terephthalate) (PBAT). The discovered enzyme has predicted arylesterase activity and is induced by PBAT added to the growth medium
Project description:Plants from the Nepenthes genus, which enumerates approximately 120 species, possess specialized pitchers enabling them to capture and digest various preys, mainly arthropods, from which the plants derive nutrients. The pitcher fluid contains many molecules of noteworthy importance, including antimicrobial compounds, traditionally used in medicine, as well as hydrolytic enzymes for prey digestion. In this study, polyesters films made from poly(ethylene terephthalate) (PET) and from poly(butylene adipate -co- terephthalate) (PBAT) were incubated in the pitcher of the carnivorous plants Nepenthes alata and Sarracenia purpurea. High performance liquid chromatography analysis revealed hydrolysis into their corresponding monomers, while hydrolysis efficiency was up to ten times higher in the presence of dried mealworm Tenebrio molitor and jasmonic acid. Proteomic analysis indicated the presence of the aspartic proteinase nepenthesin in most conditions, with high abundance in 70% of polyester-containing conditions compared to those without polyesters. Molecular docking simulations further suggested that nepenthesin has the potential to hydrolyze polyesters. While in contrast to cutinases there is only little information on hydrolysis of PET and PBAT by proteases in the literature, this work clearly demonstrates hydrolysis of both PET and PBAT by the recombinant protease nepenthesin, releasing similar amounts of TPA as the cutinase from Humicola insolens. These results suggest carnivorous plant fluids as a source for new enzymes for industrial applications such as for polyester hydrolysis.
Project description:<p>The increasing application of biodegradable mulch films in agriculture has raised concerns regarding the potential persistence of biodegradable microplastics (BMPs) in soil and their subsequent ecological impacts. Although these materials are designed to mineralize, their actual rates of breakdown under field conditions vary widely, and the role of plant roots in modulating BMP transformation through the rhizosphere effect remains poorly understood. In particular, how the complex biochemical environment of the rhizosphere influences BMP degradation and byproduct accumulation represents a critical knowledge gap. Here we show that the soybean rhizosphere significantly enhances the degradation of 1% (w/w) large (998.7 ± 74.6 μm) poly(butylene adipate-co-terephthalate) microplastics (PBAT-MPs), whereas small (145.6 ± 3.1 μm) particles remain largely protected within soil aggregates over a 70-day growth cycle. This size-dependent effect is accompanied by preferential hydrolysis of aliphatic adipate units, leading to greater accumulation of degradation monomers in the rhizosphere than in bulk soil. We further demonstrate that PBAT degradation is associated with increased microbial biomass, altered soil carbon pools, and the enrichment of Proteobacteria, particularly Bradyrhizobium and Ramlibacter, which are linked to PBAT hydrolysis and metabolite utilization. These findings redefine the role of plant roots in regulating the fate of biodegradable microplastics in soil and highlight that biodegradable mulches cannot be assumed to degrade benignly under realistic agricultural conditions. Our work underscores the need for rhizosphere relevant criteria when assessing the environmental safety of biodegradable plastics.</p>
2026-01-07 | MTBLS12524 | MetaboLights
Project description:Profiling of the bacterial community and the degradative capability of newly isolated poly(lactic acid) (PLA) and poly(butylene succinate) (PBS)-degrading bacteria from coastal samples
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.
2023-11-22 | PXD038098 | Pride
Project description:Enrichment of Microbial Communities in Film Surface Soil Drives the Variation of Poly(butylene adipate-co-terephthalate) Degradation Potential in Different Types of Soils
| PRJNA647252 | ENA
Project description:Industrial WWTP sludge as a source of potential plastic-degrading enzymes