Metagenomics-guided targeted isolation and mechanistic elucidation of haloalkaliphilic bisphenol A-degrading...

Bisphenol A (BPA), a typical endocrine-disrupting compound, poses significant environmental risks. Efficient bioremediation in high-salinity and alkaline environments, such as saline-alkaline industrial wastewater and landfill leachate, remains challenging due to the lack of microorganisms capable of maintaining activity under extreme conditions. Here, this study developed a strategy integrating metagenomic functional prediction with targeted enrichment and isolation. Soil microcosm experiments combined with metagenomic analyses identified soda saline-alkaline soils with high BPA degradation potential, and predicted microbial degradation predominantly via hydroxylation, with archaeal involvement also suggested. Guided by these predictions, 14 saline-alkaline-tolerant BPA-degrading bacterial strains (13 genera) and 20 haloalkaliphilic archaeal strains (16 genera) were successfully isolated. The proportion of BPA-degrading archaea (95.24%) was higher than bacteria (58.33%), challenging the view that this function is restricted to bacteria and fungi. Genomic analyses revealed bacterium Pseudomonas reidholzensis SAS-B12 and archaeon Natronomonas gomsonensis SR-A11 degrade BPA via hydroxylation, with differing downstream ring-cleavage pathways. SR-A11 also exhibited high laccase activity, suggesting multi-enzyme synergistic degradation. Response surface methodology optimization showed SAS-B12 achieved ∼50% BPA degradation under simulated saline-alkaline wastewater (pH 8.3, salinity 2.3%), and SR-A11 achieved similar efficiency under extreme conditions (pH 9.8, salinity 23.6%). This study expands the phylogenetic diversity of BPA-degrading microorganisms and provides microbial resources, enzymatic insights, and methodological support for targeted bioremediation in saline-alkaline wastewater.