Detection of the quorum sensing signals in methanogenic Archaea

Abstract:

Abstract: Methanosaeta harundinacea 6Ac displayed a cell-density dependent cell morphology transition between short rods (3μm－5μm) and filaments (＞ 200μm) ，implying a quorum sensing system in this archaeon.[Objective］This study aimed to confirm that cell morphology related quorum sensing exists in Methanosaeta harundinacea.[Methods］By using the bioassay of Agrobacterium tumefaciens NTL4，we determined the presence of acyl homoserine lactones (AHLs) in the spent cultures of Methanosaeta harundinacea 6Ac and other three methanogens．A chemical synthetic AHL，N-(β-Ketooctanoyl) -L-homoserine lactone was added into the culture of short rods to detect the morphology change.[Results］We determined that AHLs were produced by Methanosaeta harundinacea，Methanosarcina mazei，Methanothermobacterthermautotrophicus and Methanobacterium formicicum． Addition of N-(β-Ketooctanoyl) -L-homoserine lactone into theculture of Methanosaeta harundinacea 6Ac stimulated the formation of filamentous cells．［Conclusion］This study indicates that AHL-based quorum sensing may be used by several species of methanogenic Archaea．

Key words:Keywords: methanogenic Archaea，quorum sensing，N-acyl-homoserine lactones