Title Characterization of Quorum-Quenching Bacteria Isolated from Biofouled Membrane Used in Reverse Osmosis Process
Author Sooyoung Moon1, Xinxin Huang1, Sung-Chan Choi2, and Young-Sook Oh1*
Address 1Myongji University, 2Hallym University
Bibliography Korean Journal of Microbiology, 50(2),128-136, 2014
DOI http://dx.doi.org/10.7845/kjm.2014.4017
Key Words Pseudomonas aeruginosa, AHL lactonase, biofilm, quorum quenching, quorum sensing
Abstract Acyl homoserine lactone (AHL) lactonase has been proved to be the AHL-degrading enzyme with the highest substrate specificity for AHL molecules and has shown a considerable potential as low-cost and efficient quorum quenching (QQ) technique. However, few studies focused on its inhibitory effect on biofilm formation which is also a quorum sensing (QS)-regulated phenomenon. In this study, QQ activity of six isolates from biofouled reverse osmosis membranes was studied using Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NTL4 as biosensors under various conditions. All of the isolates belonged to the genus Bacillus and showed QQ activity regardless of the acyl chain length or substitution of AHL molecule. The isolates were capable of significantly inhibiting biofilm formation (46.7–58.3%) by Pseudomonas aeruginosa PAO1 and produced heat-sensitive extracellular QQ substances. The LC-MS analysis of the QQ activity of a selected isolate, RO1S-5, revealed the degradation of N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C12 AHL) and the production of corresponding acyl homoserine (3-oxo-C12-HS), which indicated the activity of AHL lactonase. The broad AHL substrate range and high substrate specificity suggested that the isolate would be useful for the control of biofilm-related pathogenesis and biofouling in industrial processes.
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