Preservation and reactivation strategies for quorum quenching media to combat membrane biofouling

Abstract

Microbial quorum quenching (QQ), which addresses biofouling resistant to physical and chemical methods, presents a compelling solution. Enhancements in sustainability are imperative to ensure its long-term stability. This study explores QQ media preservation for extended use. Three media types were tested over 150 days: fresh BH4 cells, preserved/reactivated BH4 cells, and BH4 cell extracts. Initial QQ activities ranged in the appropriate levels from 1.08 to 1.24 h−1. Preservation in 50 mM Tris-HCl at 4 °C showed that media with whole cells retained approximately 60 % activity after 60 days, unlike cell extract media, which lost all activity. However, the dehydration and reactivation of BH4 cell media fully recovered the initial QQ activity while maintaining it for 150 days. In MBR tests, reactivated QQ media performed as effectively as those prepared with freshly cultured BH4 cells, delaying membrane fouling by 2-fold. Revitalizing QQ media in combination with chlorine-based chemically enhanced backwashing (CEB) further delayed fouling by 2.5 times compared to CEB alone. Reactivated QQ media retained robust activity even after prolonged MBR use. This study showcases the effectiveness of dehydration and reactivation techniques for preserving QQ media, ensuring its reliable long-term storage and utilization. However, further enhancements are necessary to optimize cell viability.