Quorum sensing in halophilic bacteria: detection of N-acyl-homoserine lactones in the exopolysaccharide-producing species of Halomonas.
Some members of the moderately halophilic genus Halomonas, such as H. eurihalina, H. maura, H. ventosae and H. anticariensis, produce exopolysaccharides with applications in many industrial fields. We report here that these four species also produce autoinducer molecules that are involved in the cell-to-cell signaling process known as quorum sensing. By using the N-acyl homoserine lactone (AHL) indicator strains Agrobacterium tumefaciens NTL4 (pZRL4) and Chromobacterium violaceum CV026, we discovered that all the Halomonas strains examined synthesize detectable AHL signal molecules. The synthesis of these compounds was growth-phase dependent and maximal activity was reached during the late exponential to stationary phases. One of these AHLs seems to be synthesized only in the stationary phase. Some of the AHLs produced by H. anticariens FP35(T) were identified by gas chromatography/mass spectrometry and electrospray ionization tandem mass spectrometry as N-butanoyl homoserine lactone (C(4)-HL), N-hexanoyl homoserine lactone (C(6)-HL), N-octanoyl homoserine lactone (C(8)-HL) and N-dodecanoyl homoserine lactone (C(12)-HL). This study suggests that quorum sensing may also play an important role in extreme environments.
Llamas
Inmaculada
I
Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083-0688, USA.
Quesada
Emilia
E
Martínez-Cánovas
Maria José
MJ
Gronquist
Matthew
M
Eberhard
Anatol
A
González
Juan E
JE
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry; D002455:Cell Division; D020632:Halomonas / Q000737:chemistry* / Q000145:classification / Q000166:cytology / Q000378:metabolism*; D011134:Polysaccharides / Q000096:biosynthesis*; D021241:Spectrometry, Mass, Electrospray Ionization
D011134:Polysaccharides; C088386:homoserine lactone; D015107:4-Butyrolactone