Lips, S. | Search bioRxiv

bioRxiv2024

Metagenomic analyses of the plastisphere reveals a common functional potential across oceans

Trillions of plastic particles have accumulated in the oceans, covered by microbial biofilms (termed the "plastisphere") whose functional potential remains unexplored. We evaluated genome-resolved bacterial metagenomes of the plastisphere from the North Atlantic and North Pacific garbage patches and compared their structure and functional potential to ambient plankton. Our data revealed a characteristic genetic potential of the plastisphere with functionally equivalent taxonomic units across both oceans. We found fewer coding genes, smaller genome sizes and lower GC-content in plankton in comparison to the plastisphere, despite residing in the same environment, reflecting a greater nutrient demand in the plastisphere. A functional gene analysis confirmed that the plastisphere consists of microorganisms with a higher potential to control their nutrient supply, metabolize a wider range of carbon sources, attenuate free radicals and use alternative energy sources like anoxygenic photosynthesis. Our results suggest that the overriding factor for the high functional similarity of the plastisphere in both oceans is the habitat for biofilm formation with the potential to support mutualism and nutrient sharing making genomic streamlining as found in plankton, unnecessary. Consequently, increasing plastic pollution promotes the expansion of new functional units within oligotrophic oceans, with the potential to impact biogeochemical cycles.

microbiology↗

bioRxiv2022

16s rRNA gene sequence analysis of the microbial community on microplastic samples from the North Atlantic and Great Pacific Garbage Patches

The exponential increase in plastic production has led to their accumulation in the environment, particularly in oceans, polluting these environments from the shore to the open ocean and even sea ice in the pole regions. We compared microbial communities on plastic particles, known as "Plastisphere", collected from the Atlantic and Pacific oceans gyres in the Summer of 2019 and subsequently looked for potential plastic degraders. We applied a 16S rRNA amplicon sequencing approach to decipher differences and similarities in colonization behaviour between these two gyres. Two polymer types include plastics: polyethylene (PE) and polypropylene (PP). We found that microbes differed significantly between the two oceans and identified thirty-two differentially abundant taxa at the class level. Proteobacteria, Cyanobacteria and Bacteroidota were the most prominent relative abundant phyla in the two oceans. Finally, according to the current literature, we found 40 genera documented as potential plastic degraders. This study highlights the importance of the biogeographical location with respect to microbial colonization patterns of marine plastic debris, differing even in the open oceans. Furthermore, the wide distribution of potential plastic-degrading bacteria was shown.

bioinformatics↗