Dynamics and enzymatic degradation of exopolymer particles under increasing concentrations of silver ions and nanoparticles during a marine mesocosm experiment

Pollution of the marine environment is an emerging threat. Nowadays, engineered nanoparticles (<100 nm) such as zinc, copper and silver are widely used antimicrobial agents, therefore often present in daily-life products. Consequently, demand production expected to increase. Here, we specifically focus on (AgNP). Once released into environment, AgNPs pose obvious ecotoxicological risk, potentially affecting ecosystem structure functioning. For instance, phytoplankton-derived exudates, rich acidic polysaccharides amino acids, can abiotically aggregate microgels transparent exopolymer particles (TEP) Coomassie stainable (CSP). Hence, bridge dissolved particulate size fractions facilitate formation with organic mineral particles. Both physical chemical properties make TEP CSP attractive nutrient hotspots for heterotrophic bacterioplankton. Bacteria, turn, utilize extracellular enzymes access these carbon nitrogen pools. However, knowledge about mechanisms by which might interact affect biogeochemical cycling still insufficient. Therefore, conducted a mesocosm experiment Eastern Mediterranean Sea investigated effects environmentally relevant concentrations ions (Ag+) AgNP (i.e., area abundance) along enzymatic activity measurements. Our results showed that cyanobacteria were likely primary source ultra-oligotrophic Sea. Also, contributed more microgel pool than TEP, indicated strong relationship between microbial dynamics. While Ag+ or AgNP) had overall only marginal effects, both species affected relationships cell-specific LAPase APase phosphate levels. Thus, have potential regulate future studies needed derive robust understanding pollution coupling degradation follow-on effect cycles.