Quorum sensing (QS) or cell-to-cell communication is a process by which bacteria produce and detect signal molecules and thereby coordinate their behavior in a cell-density dependent manner. The sequenced genome of the marine bioluminescent strain S. woodyi MS32 contains genes coding for the AHL QS system. The goal of this study is to identify the AHL QS communication system present in this bacterium and to understand its role in biofilm formation. The objective is also to develop a new marine QS biosensor from this strain. By coupling bacterial biosensor assays and high resolution liquid chromatography mass spectrometry (LCMS), we showed that S. woodyi synthesized N-octanoyl-L-homoserine lactone (C8-AHL). We studied the effect of a wide range of AHLs on the S. woodyi luminescence and only C8-AHL molecule induces luminescence. A mutation of the AHL system genes, the luxI synthase or the luxR receptor makes S. woodyi non-luminescent but surprisingly S. woodyi mutant and wild type have the same adhesion and biofilm formation pattern. On the other hand, the QS mutation reduces phagocytosis of S. woodyi by amoeba eukaryotic cells.