Development of a new approach to membrane bioreactor technology: enhanced quorum quenching activity

Abstract

Quorum Quenching (QQ) is a mechanism that prevents cell to cell communication and has recently used as an effective control method against biofouling in membrane bioreactors (MBRs). Rotary microbial carrier frame (RMCF) is an innovative application used in QQ-controlled MBRs that provides immobilization medium to QQ bacteria. However, it eventually caused to decrease in QQ activity as a result of a decline in the number of viable QQ cells in theimmobilization media over time, especially during long-term MBR operations. In this study, the effect of regeneration ofthe QQ cells in the immobilization media on biofouling control in MBR was investigated. The growth kinetic of Rhodococcus sp. BH4 as model QQ bacteria was revealed and the bacteria regeneration time was obtained as 28.3 days. In the operation of the regenerated group, an additional QQ activity of 38.2% was achieved compared to control during a 14 day-duration of QQ-controlled MBR operation. It could be indicated that regenerated QQ bacteria reduced SMP and EPS by degrading the signal molecules, thus more efficient control of membrane fouling was achieved.