Regulatory mechanism by which exogenous AHLs enhance the degradation of bisphenol A by Pseudomonas asiatica P1

Bisphenol A (BPA) poses multiple risks to human health, and it has become a critical environmental pollution issue. The advantage of bacterial degradation of BPA has become more prominent, and enhancement methods have become increasingly diverse. Using quorum sensing to regulate functional bacteria and genes to enhance the bacterial degradation efficiency of BPA serves as a highly promising new approach. This study investigated the effect of adding exogenous N-hexanoyl-L-homoserine lactone (C6-HSL) on the degradation of BPA by Pseudomonas asiatica P1 (strain P1) and analyzed the regulatory mechanism of the signaling molecules. The results showed that exogenous homoserine lactone signaling molecules (AHLs) could enhance the BPA degradation efficiency of strain P1, with 10 μM C6-HSL demonstrating the most significant enhancement, increasing the degradation rate by 12.4 % compared with the control group and producing products such as benzoic acid and succinic acid. In terms of the regulatory mechanism, C6-HSL preferentially induced a 5.18-fold upregulation in the expression of the AHL receptor-encoding gene LasR. Subsequently, LasR regulates the upregulation of hub genes such as bvgS and aruS , ultimately achieving an upregulation of BPA degradation genes through hierarchical regulation. This led to an enhancement in the initial degradation step of BPA and the activation of the benzoic acid degradation pathway. This study analyzed the potential of C6-HSL to enhance microbial BPA degradation and, for the first time, clarified the mechanism by which C6-HSL enhanced bacterial BPA degradation efficiency through hierarchical regulation. • AHLs enhanced the BPA degradation ability of strain P1. • C6-HSL strengthened the hydroxylation degradation pathway of BPA. • C6-HSL activated the benzoic acid degradation pathway. • C6-HSL achieved hierarchical control over the BPA degradation through hub genes.