Bacterial AHL-acylases (acyl homoserine lactonase) (AiiO, AidH) from genus Ochrobactrum and related bacteria are different from previously described AHL-acylases such as PvdQ, QuiP (P.aeriginosa) HacA HacB (P.syringea which belong to Ntn-hydrolase superfamily Czajkowski et al.) and different from AHL-lactonase of B. thuringensis and A. tumefasciens (which are metallo-beta lactamases). AHL-acylase inactivates N-acyl homoserine lactone (AHL) quorum sensing signal molecules (lactonases are also inactivating enzymes). AHL-acylases could be useful for the control of development of infections caused by pathogenic bacteria and their persistence in respective hosts. The three fungi sequences are genes without real introns (horizontal transfer?). There are other N-acyl homoserine lactonase (AiiA) not alpha/beta hydroalses but Metallo-B-lactamases