New insights into biofilm control and inhibitory mechanism analysis based on the novel quorum quenching bacterium Acinetobacter pittii HITSZ001.

Quorum quenching (QQ) has proven its potential as an innovative approach for biofouling control in membrane bioreactor (MBR) for wastewater treatment. In this study, a novel quorum-quenching bacterium, Acinetobacter pittii HITSZ001, was isolated from activated sludge. In contrast to previous studies, in which QQ bacteria were directly applied in the MBR system, in this investigation, this strain was co-cultured with Pseudomonas aeruginosa to illustrate the inhibitory effect of the QQ strain on the key genes involved in biofilm formation. The types of QQ enzymes secreted by A. pittii HITSZ001 and its functional ahlm gene was also identified. To better apply this strain, it was encapsulated in the QQ beads with great activities, which could well adapt to a complex real activated sludge environment and effectively controlled biofilm formation on the membrane. The results of this study suggest that A. pittii HITSZ001 represents a novel and promising strain for biofilm mitigation to promote MBR performance and that it would be economically and technically feasible to expand biofouling control with this strain to plant-scale MBRs and similar environmental engineering systems. [Display omitted] • A quorum quenching strain was isolated and its mechanism was identified. • The QS genes in Pseudomonas aeruginosa were downregulated by QQ strain. • The encapsulated QQ strain can inhibit biofilm formation effectively. • A new biological method to detect the quantity of AHL was improved. [ABSTRACT FROM AUTHOR]