Short Chain N-acyl Homoserine Lactone Production by Soil Isolate Burkholderia sp. Strain A9

In the bacteria kingdom, quorum sensing (QS) is a cell-to-cell communication that relies on the production of and response to specific signaling molecules. In proteobacteria, N-acylhomoserine lactones (AHLs) are the well-studied signaling molecules. The present study aimed to characterize the production of AHL of a bacterial strain A9 isolated from a Malaysian tropical soil. Strain A9 was identified as Burkholderia sp. using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rDNA nucleotide sequence analysis. AHL production by A9 was detected with two biosensors, namely Chromobacterium violaceum CV026 and Escherichia coli [pSB401]. Thin layer chromatography results showed N–hexanoylhomoserine lactone (C6-HSL) and N–octanoylhomoserine lactone (C8-HSL) production. Unequivocal identification of C6-HSL and C8-HSL was achieved by high resolution triple quadrupole liquid chromatography-mass spectrometry analysis. We have demonstrated that Burkholderia sp. strain A9 produces AHLs that are known to be produced by other Burkholderia spp. with CepI/CepR homologs.