The invention is directed to methods and compositions that inhibit pathogen proliferation. More specifically, in various embodiments the present invention relates to activities of acylases as disruptors of bacterial disease, and thus virulence, and the utility of acylases as control agents for plant disease.

The present disclosure belongs to the technical field of biological control and prevention, and it was found that Pseudomonasnitroreducens strain HS-18 has good degradation activity on AHLs with C4-C14 chain length, with an efficient and notable degradation effect, providing a new biocontrol agent for prevention and treatment of AHLs-mediated pathogens provides and broadening the quorum quenching species of AHL signaling molecules. By using molecular biology technologies, AHL-quenching genes for HS-18, i.e., the encoding genes aigA and aigC of N-acyl homoserine lactone acyl transferase are cloned. The genes aigA and aigC have broad-spectrum and efficient quenching activities on AHLs with different side chain lengths and different side chain substituents. The expression of aigA and aicC can significantly weaken the motility of AHL-mediated pathogens, the formation of biofilm and the production of virulence factors and significantly weaken the pathogenicity of pathogens to the host plant.