Transparent exopolymer particles (TEPs) are extracellular acidic polysaccharides produced by phytoplankton and bacteria in saltwater, freshwater, and wastewater.
TEP concentration is especially enhanced by haptophyte phytoplanktonic dominance, solar radiation exposure, and close proximity to sea ice.
[4] High concentrations of TEPs in the surface ocean slow the sinking of solid particle aggregations, prolonging pelagic residence time.
TEPs may provide an upward flux of materials such as bacteria, phytoplankton, carbon, and trace nutrients.
[7] TEPs are formed from cell surface mucus sloughing, the disintegration of bacterial colonies, and precursors released by growing or senescent phytoplankton.
[9] While most exopolymeric substances range from loose slimes to tight shells surrounding cells, TEPs exist as individual particles, allowing them to aggregate and be collected by filtration.
The bacterial colonies associated with TEPs tend to be dominated by Alteromonadaceae, specifically taxonomic units previously associated with microgel habitats, Marinobacter and Glaciecola.
[21] TEPs have been referred to as ‘protobiofilms’ due to their intense colonization by bacteria, displaying many characteristics of a biofilm without being attached to a surface.