Catalyzes the deacylation of acyl-homoserine lactone (AHL or acyl-HSL), releasing homoserine lactone (HSL) and the corresponding fatty acid. Possesses a specificity for the degradation of long-chain acyl-HSLs (side chains of seven or more carbons in length). Appears to be the acyl-HSL acylase that underlies the ability of P.aeruginosa to degrade and utilize certain acyl-HSLs as growth nutrients, including one of its own quorum signals, 3-oxo-C12-HSL. Is thought to have a role in quorum quenching. an N-acyl-L-homoserine lactone + H2O = a carboxylate + L-homoserine lactone Heterodimer of an alpha subunit and a beta subunit processed from the same precursor. By long-chain acyl-HSLs, but not short-chain ones. AHL-mediated signaling mediates quorum sensing in many species of Proteobacteria, regulating hundreds of genes, including many that code for extracellular virulence factors. Belongs to the peptidase S45 family.