[Objective]Virulence of pathogens can be inhibited by quornm quenching( QQ) in the way of Aii A protein degradating AHLs. To construct Bacillus subtilis which is capable of efficiently expressing Aii A,in Bacillus subtilis experssion system,the ability of the Pspac promoter to express Aii A is needed to be tested.[Methods]Pspac and aiiA gene were ligated by SOE PCR. And the Pspac-aiiA fragment was inserted into PHY300 PLK then transfer into Bacillus subtilis C11. The AHLs degradation ability was detected. [...