A multi-OMIC characterisation of biodegradation and microbial community succession within the PET plastisphere
Abstract Background Plastics now pollute marine environments across the globe. On entering these environments, plastics are rapidly colonised by a diverse community of microorganisms termed the plastisphere. Members of the plastisphere have a myriad of diverse functions typically found in any biofil...
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Published in | Microbiome Vol. 9; no. 1; pp. 1 - 22 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
London
BioMed Central
21.06.2021
BMC |
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
Background
Plastics now pollute marine environments across the globe. On entering these environments, plastics are rapidly colonised by a diverse community of microorganisms termed the plastisphere. Members of the plastisphere have a myriad of diverse functions typically found in any biofilm but, additionally, a number of marine plastisphere studies have claimed the presence of plastic-biodegrading organisms, although with little mechanistic verification. Here, we obtained a microbial community from marine plastic debris and analysed the community succession across 6 weeks of incubation with different polyethylene terephthalate (PET) products as the sole carbon source, and further characterised the mechanisms involved in PET degradation by two bacterial isolates from the plastisphere.
Results
We found that all communities differed significantly from the inoculum and were dominated by Gammaproteobacteria, i.e.
Alteromonadaceae
and
Thalassospiraceae
at early time points,
Alcanivoraceae
at later time points and
Vibrionaceae
throughout. The large number of encoded enzymes involved in PET degradation found in predicted metagenomes and the observation of polymer oxidation by FTIR analyses both suggested PET degradation was occurring. However, we were unable to detect intermediates of PET hydrolysis with metabolomic analyses, which may be attributed to their rapid depletion by the complex community. To further confirm the PET biodegrading potential within the plastisphere of marine plastic debris, we used a combined proteogenomic and metabolomic approach to characterise amorphous PET degradation by two novel marine isolates,
Thioclava
sp. BHET1 and
Bacillus
sp. BHET2. The identification of PET hydrolytic intermediates by metabolomics confirmed that both isolates were able to degrade PET. High-throughput proteomics revealed that whilst
Thioclava
sp. BHET1 used the degradation pathway identified in terrestrial environment counterparts, these were absent in
Bacillus
sp. BHET2, indicating that either the enzymes used by this bacterium share little homology with those characterised previously, or that this bacterium uses a novel pathway for PET degradation.
Conclusions
Overall, the results of our multi-OMIC characterisation of PET degradation provide a significant step forwards in our understanding of marine plastic degradation by bacterial isolates and communities and evidences the biodegrading potential extant in the plastisphere of marine plastic debris. |
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ISSN: | 2049-2618 2049-2618 |
DOI: | 10.1186/s40168-021-01054-5 |