Degradation of N-acylhomoserine lactones, the bacterial quorum-sensing molecules, by acylase

Porcine kidney acylase I was shown to be able to deacylate N-acylhomoserine lactones, a family of chemicals employed by Gram-negative bacteria as quorum-sensing molecules for cell population density-dependent growth (such as biofilm formation). The enzyme transformed both N-butyryl-and N-octanOyl-L-homoserine lactones into Lhomoserine. An optimal pH of 10 at 23 degreesC and an optimal temperature of 76 degreesC at pH 9 were found for the enzyme in hydrolyzing N-butyryl-homoserine lactone. At pH 9 and 23 degreesC, the enzymatic catalysis had a Km of 81 +/- 3 mM and a k(cat):a, of 127 + 2 nmol min - I per mg. The enzyme was also shown to be able to reduce the biofilm growth in an aquarium water sample. Potential physiological significance and medicinalhndustrial applications of the N-acy1homoserine lactone-degrading activity of acylase are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.