Development and Biochemical Characterization of Quorum Quenching Enzyme from Deep-Sea Bacillus velezensis DH82.

Quorum quenching (QQ) is of interest for potential application as a sustainable strategy for bacterial disease control via communication interruption. The QQ enzyme can be used as a good alternative antagonist to combat antibiotic abuse and bacterial resistance. Here, genomic DNA sequencing was performed on N-acyl homoserine lactonase from the deep-sea strain Bacillus velezensis DH82 with Cluster of Orthologous Groups of proteins (COGs) annotation. The homologous sequences with β-lactamase domain-containing protein were predicted to be potential QQ enzymes and were cloned and expressed to study their quorum quenching properties by comparing them with the reported enzyme AiiA(3DHB). The experimental results of enzyme activity analysis and steady-state kinetics, as well as enzyme structure and substrate docking simulations and predictions, all consistently demonstrated that YtnP(DH82) presented superior enzyme structural stability and higher degradation efficiency of N-acyl homoserine lactones than AiiA(DH82) under the effects of pH, and temperature, and performed better on short -chain and 3-O-substituted AHSLs. The findings revealed the structural and biochemical characterization of YtnP(DH82) from the deep sea, which provide the capacity for further application in sustainable aquaculture as an alternative to antibiotics.