ABSTRACT
Bacterial and microalgal exopolymers coat a wide range of particulate material. They are coincidently ingested by consumers during the active ingestion of microbial cells and other particulates. Since microbial consumers often key on particles during feeding, such particles are ideal to coat with radiolabeled exopolymers for use in feeding experiments. Methods are presented for: qualitatively observing exopolymers on natural particles which minimize the deformation and losses commonly associated with conventional preparation techniques for light and electron microscopy and conducting feeding experiments to determine the ingestion and absorption efficiencies of exopolymers by animals. Advantages of the methods are that: the exopolymers can be added to natural sediments or seawater, and thus, grazing experiments are conducted in the presence of natural food sources and for short term incubations, the radiolabel will be primarily associated with the exopolymer. It also includes the exopolymer coatings surrounding the particles will mimic the biofilms associated with natural particles.
