Publications

Authors:

Salini, Andrea; Zuliani, Luca; Gonnelli, Paolo Matteo; Orlando, Marco; Odoardo, Andrea; Ragno, Daniele; Aulitto, Martina; Zaccone, Claudio; Fusco, Salvatore

Title:

Plastic-Degrading Microbial Consortia from a Wastewater Treatment Plant

Year:

2024

Type of item:

Articolo in Rivista

Tipologia ANVUR:

Articolo su rivista

Language:

Inglese

Format:

Elettronico

Referee:

Sì

Name of journal:

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

ISSN of journal:

1422-0067

N° Volume:

25

Number or Folder:

23

Page numbers:

1-17

Keyword:

activated sludge; biocatalytic recycling; microbial plastic degradation; plastic-active enzymes; polyesters; polyethylene terephthalate (PET); polylactic acid (PLA); thermophilic enzymes; wastewater treatment plant (WWTP)

Short description of contents:

Plastic waste pollution has become a global crisis, with millions of tons of plastic expected to accumulate in landfills and in natural environments, posing a serious threat to wildlife and human health. As current recycling methods remain inefficient, there is an urgent need for innovative enzymatic solutions to break down plastics and enable a circular economy approach. In this study, we explore the plastic-degrading potential of microorganisms enriched from activated sludge (AS) sourced from a municipal wastewater treatment plant (WWTP)-a known microplastic-contaminated industrial niche. Five microbial consortia (i.e., microbiomes) were enriched under selective pressure using low-carbon conditions and high concentrations of polyester polymers, including post-consumer PET, post-consumer PLA, and virgin PLA. Enrichment was performed for 100 days at 37 °C and 50 °C, followed by microbiomes isolation and metagenomic analysis to identify plastic-active bacteria and their enzymes. The results revealed that PLA polymers, but not post-consumer PET, were effectively degraded by the microbiomes, as confirmed by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC), showing significant molecular weight reduction compared to the abiotic controls. Microbial community analysis highlighted a distinct enrichment profile driven by the polymer composition and the temperature. At 50 °C, the Bacillales order became the predominant population, whereas at 37 °C, a more diverse community within the Proteobacteria and Actinobacteria phyla were selected. Nonetheless, the enriched microbial communities at both temperatures included phyla with members known for polyester degradation. Moreover, at 50 °C, enrichment of putative PET/PLA hydrolases was also observed. These findings suggest that AS microorganisms are a reservoir of polyester-active enzymes, particularly PLA-depolymerases, and hold promise for advancing biotechnological strategies to mitigate plastic pollution through re- and up-cycling.

Web page:

https://doi.org/10.3390/ijms252312747

Product ID:

143443

Handle IRIS:

11562/1147767

Last Modified:

April 13, 2025

Bibliographic citation:

Salini, Andrea; Zuliani, Luca; Gonnelli, Paolo Matteo; Orlando, Marco; Odoardo, Andrea; Ragno, Daniele; Aulitto, Martina; Zaccone, Claudio; Fusco, Salvatore, Plastic-Degrading Microbial Consortia from a Wastewater Treatment Plant «INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES» , vol. 25 , n. 23 , 2024 , pp. 1-17

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