RESOURCE-ACQUISITION INTERFACE – Extracellular digestion followed by absorption

• fungal osmotrophy
• bacterial extracellular hydrolysis
• saprotrophic digestion
• animal digestive systems
• external liquefaction of prey

Operational definition

Acquisition mechanism.

The chemical breakdown of polymers, tissues, or particles outside the absorbing cell membrane, followed by uptake of the resulting soluble products.

The digestive enzymes may be:

• secreted into the environment;
• displayed on the cell surface;
• confined within an external or internal digestive cavity that remains outside the absorbing cells.

This is characteristic of fungi, many bacteria, and animal digestive systems. It differs from phagocytosis because the main substrate is chemically reduced to absorbable molecules before cellular uptake.