Model bacteria for biofouling research of reverse osmosis membranes

The selection of suitable model bacteria is closely related to biofouling control and mechanism verification. In this work, we discussed the necessity of model bacteria for biofouling research and control. According to our investigation, bacteria can only be defined as model bacteria if three conditions are met: 1) robust attachment capacity to the RO membrane surface; 2) high relative abundance; and 3) high biofouling potential. More importantly, a list of reverse osmosis (RO) biofouling-related model bacteria was given for subsequent research. Bacteria with high secretion capacity tend to cause more severe biofouling. Notably, potential disinfection-resistant bacteria (DRB), which possessed high capacity in extracellular polymeric substance secretion and biofilm formation, were prevalent in fouled RO membranes and deserved priority attention. With the proposed criteria, we hope to provide new insights and principles for selecting model bacteria in RO membrane technology development. • Criteria of model bacteria for biofouling research were proposed. • Bacteria with high secretion capacity tend to cause severe biofouling. • Disinfection-resistant bacteria should be prioritized in biofouling studies.