Production, characterization, and powder preparation of quorum quenching acylase AiiO for pathogen control

Acylase AiiO is a novel quorum quenching enzyme with a broad substrate spectrum of acyl-homoserine lactones (AHLs) and has promising prospects in pathogen control. In this work, acylase AiiO production by a recombinant E. coli strain and its characterization were investigated; the acylase powder was further prepared and evaluated for effectiveness. A strategy of auto-induction combined with temperature regulation was developed to improve AiiO production. For the soluble AiiO protein in the cells, maximum production of 214.3 ± 9.4 mg/L was obtained in the fermenter. The purified acylase displayed an obvious AHL-degrading specific activity of 19.2 ± 0.56 U/mg. Sucrose, as the protective agent, maintained good stability of the acylase powder, in which the acylase remained 89.6 and 71.9% of its initial specific activity after storage at 4 °C for 3 and 6 months, respectively. The acylase powder could prominently decrease the expression levels of virulence-related factors of Pseudomonas aeruginosa. Based on the high-yield production and effective powder preparation, the quorum quenching acylase AiiO has the potential to be used in the clinical treatments of pathogenic infections.