Limits of bacterial osmoadaptation during planktonic and biofilm growth: a step toward effective biofouling control

, but oscillating salinity (e.g., 0%-7%) favors neither. Oscillating salinity may, therefore, offer a new mechanism for controlling microbial growth that circumvents community adaptation to environmental conditions.IMPORTANCEReverse osmosis filtration is a widely used technology to address the scarcity of clean freshwater. However, the efficiency of reverse osmosis systems is challenged by microbial biofouling, as microbial communities adapt to the environmental conditions within the system and form biofilms on the membranes. This study investigated the impact of fluctuating salinity on the growth and survival of halophilic and halotolerant bacteria. The findings suggest that oscillating salinity disrupts the growth and viability of both types of bacteria, in both planktonic cultures and biofilms. The study, thus, supports the hypothesis that fluctuating salinity in reverse osmosis systems could reduce biofouling by impeding microbial adaptation to salinity. This represents a promising new strategy for microbial control in reverse osmosis systems, potentially enhancing performance by minimizing biofouling through an environmentally friendly approach.