Extraction of extracellular polymeric substances from dam lake fresh sediments derived from crystalline bedrock

Extracellular polymeric substances (EPS) produced by microorganisms have a key role in the sedimentary compartment, e.g. promoting aggregation and biostabilisation of sediment particles increasing chemical reactivity at water/sediment interface. Therefore, proper extraction methods are needed to study this EPS matrix. In work, nine based on physical (centrifugation, sonication), (sodium hydroxide, sodium pyrophosphate, tetraborate), both (cation exchange resins, i.e. CER) treatments their combinations, as well solid:liquid ratio used for extraction, were compared quantity compositions extracted EPS. The organic carbon was quantified nature biochemical macromolecules (proteins, polysaccharides, humic-like compounds) evaluated using colorimetric methods. amount ATP an indicator cell lysis showed contamination with intracellular materials Moreover, presented large impurities due non-removal reactant salts ultracentrifugation. For tested, represented main fraction EPS, but presence humic from non-specific fraction. chemicals not recommended extract sediment. Despite low efficiency, CER, ‘soft’ methods, preferred 1:40.