Extracellular polymeric substances (EPS) can work as a highly efficient nutrient source for many microorganisms. This study investigated the influences of EPS on the bioactivities of a typical phosphate‐solubilising fungus, that is Aspergillus niger . The EPS were extracted from Rhodotorula mucilaginosa , with the addition of varying levels of inorganic phosphates. Under phosphorus (P) limitation, the cell wall thickness of A....