Figure 3:

Conceptual representation of microbial biofilms (left) subject to predation by grazing (right) without (top) or with (bottom) ENMs accumulated in the biofilms. Note that the extracellular polymeric substances (EPSs) are depicted as macromolecules (lipids, nucleic acids, carbohydrates, and proteins) that are hydrated, surrounding biofilm cells. In the presence of ENMs that impose cellular stress, EPS accumulations may increase (bottom) which could increase the overall abundance of retained ENMs in the vicinity of prey (biofilm cells) and predator (grazer or similar).