Biofouling control in reverse osmosis by nitric oxide treatment and its impact on the bacterial community

Recent discoveries regarding the regulation of the biofilm life cycle by bacterial signaling systems have identified novel strategies for manipulation of biofilm development to control the biofouling of membrane-based water purification systems. Nitric oxide (NO) signaling has been shown to induce dispersal of a wide range of single- and multi-species biofilms. However, the impact of NO-mediated biofilm dispersal on the taxa composition of natural communities as well as the potential selection for non-responding community members have rarely been addressed. Here, we investigated the effect of diethylenetriamine (DETA) NONOate, an NO donor with a long half-life, on biofilm dispersal of a bacterial community responsible for membrane biofouling to address this question. The biofilm of a complex community from a fouled industrial reverse osmosis (RO) membrane was dispersed over 50% by 500 μM of DETA NONOate treatment in a continuous flow system. Once-daily treatment with DETA NONOate in a laboratory-scale RO system demonstrated its anti-biofouling effect by delaying the transmembrane pressure increase during constant-flux filtration. Characterization of the bacterial communities of dispersed cells and remaining biofilm cells using a 16S Illumina MiSeq metabarcoding approach demonstrated that biofilm dispersal by DETA NONOate had no selection bias in the community.