Degradation of N-Acylhomoserine Lactone Quorum Sensing Signaling Molecules by Potato Root Surface-Associated Chryseobacterium Strains

Abstract

N-Acylhomoserine lactones (AHLs) are used as quorum-sensing signaling molecules by many Gram-negative bacteria. Here, 413 bacterial strains were obtained from the roots of potato plants and screened for AHL-degrading bacteria using Chromobacterium violaceum reporter strains. Sixty one isolates degraded N-hexanoyl-L-homoserine lactone (C6-HSL) within 24 h. Based on their 16S rRNA gene sequences, most of these isolates were assigned to the genus Chryseobacterium and divided into eight groups. Most of the strains degraded N-decanoyl-L-homoserine lactone (C10-HSL) and were active against 3-oxo-substituted AHLs. Groups V and VI were more effective at inactivating AHLs. One group V strain, StRB402, showed putative AHL-lactonase activity. This is the first report of AHL-degrading Chryseobacterium strains.