MARINE PLASTISPHERE STRUCTURE AND FUNCTION: INSIGHTS FROM A FLOW-THROUGH EXPERIMENT ON MICROPLASTICS IN THE WATER COLUMN

The ongoing presence of microplastics in coastal oceans has revealed the existence of a plastisphere, where microbial communities significantly differ from those in surrounding water environments, highlighting the potential impacts on biogeochemical processes in the water column. On this study, polyethylene microplastics were added to a natural sea water flow-through system over 23 days. Our main goal was to determine the effects of microplastics on biofilm formation and associated changes in community structure and functions, by means of selected hydrolytic enzyme activities of natural microbial assemblages over the time course of the experiment. We hypothesized that microplastics select for distinct microbial communities that exhibit enzymatic activities compared with microbes attached to natural particles. Biofilm formation on microplastics can influence microbial activity in the water column, potentially modifying the aggregation and sinking dynamics of particulate matter, intervening in the natural process of the ocean carbon cycle. Main results indicated that biofilm concentration around microplastics increased by more than 100% over the sampling period. Microplastics were analyzed for bacterial cell abundance, total community structure (16S rRNA gene sequencing), and potential activities of seven hydrolytic enzymes as indicators of microbial breakdown of lipids, carbohydrates, and peptides. Our preliminary results have shown microbial succession in biofilms formed around microplastics, along with community specificity at a family-level compared to natural particles. The analysis of our results could provide insights into whether microplastics serve as a carbon source for microbial communities in the water column, potentially altering nutrient cycles in coastal waters. If confirmed, further research into the broader impacts on oceanic elemental cycles will be necessary.

Presentation Preference: Oral

Primary Presenter: Astrid Zapata De Jesus, University of New Hampshire (astridzzapata@gmail.com)

Authors:

Astrid Zapata De Jesus, University of New Hampshire  (astrid.zapatadejesus@unh.edu)

Alexis Ruiz Agosto, University of Puerto Rico Humacao  (alexis.ruiz9@upr.edu)

Adriana Arce Soto, University of Puerto Rico Mayaguez  (adriana.arce1@upr.edu)

Ashley Bulseco, University of New Hampshire  (ashley.bulseco@unh.edu)

Kai Ziervogel, University of New Hampshire  (kai.ziervogel@unh.edu)