Combining quorum quenching by Rhodococcus sp. BH4 and Acinetobacter sp. DKY-1 to control biofouling in membrane bioreactors

Abstract

This study investigates a novel approach to mitigate biofouling in membrane bioreactors (MBRs) using a combinational quorum quenching (QQ) strategy. Rhodococcus sp. BH4 and Acinetobacter sp. DKY-1 were employed to disrupt intraspecies N-acyl-homoserine lactones (AHL) and interspecies autoinducer-2 (AI-2) quorum sensing, respectively. BH4 and DKY-1 were immobilized independently and the antibiofouling effects of single QQ beads and 1: 1 mixed QQ beads, both with the same final doses, were compared. While both bead types exhibited high QQ activity, the mixed QQ beads more effectively inhibited microbial biofilm formation, delaying biofouling by two times compared to 1.5 and 1.7 times for the single species beads. Additionally, the mixed QQ MBR demonstrated significantly lower extracellular polymeric substances and a notable reduction in the genus Nitrospira. This combined QQ strategy presents a promising method for enhancing antibiofouling performance in MBRs through targeted disruption of microbial communication.

Keywords: Antibiofouling; Biofilm; Membrane bioreactor; Quorum quenching; Quorum sensing.