We isolated a bacterial isolate (F7) from potable water. The strain was identified as Mesorhizobium sp. by 16S rDNA gene phylogenetic analysis and screened for N-acyl homoserine lactone (AHL) production by an AHL biosensor. The AHL profile of the isolate was further analyzed using high resolution triple quadrupole liquid chromatography mass spectrometry (LC/MS) which confirmed the production of multiple AHLs, namely, N-3-oxo-octanoyl-L-homoserine lactone (3-oxo-C8-HSL) and N-3-oxo-decanoyl-L-homoserine lactone (3-oxo-C10-HSL). These findings will open the perspective to study the function of these AHLs in plant-microbe interactions.