Quorum quenching bacteria can be used to inhibit the biofouling of reverse osmosis membranes

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Over the last few decades, significant efforts have concentrated on mitigating biofouling in reverse osmosis (RO) systems, with a focus on non-toxic and sustainable strategies. Here, we explored the potential of applying quorum quenching (QQ) bacteria to control biofouling in a laboratory-scale RO system. For these experiments, <I>Pantoea stewartii</I> was used as a model biofilm forming organism because it was previously shown to be a relevant wastewater isolate that also forms biofilms in a quorum sensing (QS) dependent fashion. A recombinant <I>Escherichia coli</I> strain, which can produce a QQ enzyme, was first tested in batch biofilm assays and significantly reduced biofilm formation by <I>P. stewartii</I>. Subsequently, RO membranes were fouled with <I>P. stewartii</I> and the QQ bacterium was introduced into the RO system using two different strategies, direct injection and immobilization within a cartridge microfilter. When the QQ bacterial cells were directly injected into the system, <I>N-</I>acylhomoserine lactone signals were degraded, resulting in the reduction of biofouling. Similarly, the QQ bacteria controlled biofouling when immobilized within a microfilter placed downstream of the RO module to remove QS signals circulating in the system. These results demonstrate the proof-of-principle that QQ can be applied to control biofouling of RO membranes and may be applicable for use in full-scale plants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A recombinant Quorum Quenching (QQ) bacterium controlled biofilm formation. </LI> <LI> Direct injection of QQ bacteria in a lab-scale RO system mitigated biofouling. </LI> <LI> QQ bacteria controlled biofouling when immobilized within a microfilter cartridge. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>