Microbial attachment and adsorption-desorption kinetic of tightly bound extracellular polymeric substances on model organic surfaces

The attachment of microbial cells onto the surface is influenced by surface properties. In this study, in order to determine the bacterial attachment and adsorption behaviors of tightly bound extracellular polymeric substances (TB-EPS) on different surfaces, four self-assembled monolayers (SAMs) carrying methyl (CH3-SAM), amino (NH2-SAM), hydroxyl (OH-SAM), and carboxyl (COOH-SAM) terminal groups were modeled. The result indicated that the bacterial attachment and the adsorption/desorption rate of TB-EPS were dependent upon the surface properties. CH3-SAM and NH2-SAM surfaces encourage the cell attachment. The adsorption rate of TB-EPS on CH3-SAM surface was the highest. The neutral and hydrophilic surface (OH-SAM) obtained the lowest cell attachment amount and TB-EPS affinity. The result indicated that the hydrophobic surface was much more favorable to the cell immobilization and TB-EPS deposition than hydrophilic surface. This work provided a foundation to control attachment of cells onto surfaces and the biofilm formation in wastewater treatment process. (C) 2015 Elsevier B.V. All rights reserved.