Enhancing Nonylphenol Biodegradation: The Role of Acetyl-CoA C-Acetyltransferase in Bacillus cereus

Nonylphenol (NP) bioremediation is constrained by the scarcity of efficient and non-pathogenic degrading strains. To clarify the role of acetyl-CoA C-acetyltransferase (AtoB) in NP degradation, we generated an <i>atoB</i>-overexpressed strain (LY-OE) from the environmentally tolerant <i>Bacillus cereus</i> LY and compared its degradation rate with the wild type using HPLC. Untargeted lipidomics was conducted to characterize metabolic responses under NP stress, and key differential lipid metabolites (DELMs) were further validated by ELISA. Additionally, AtoB concentration and ATP content were quantified using commercial assay kits in <i>Bacillus cereus</i>. LY-OE showed a markedly higher NP degradation rate (96%) than LY (85%). Lipidomic analysis identified 34 significant DELMs (VIP > 1, <i>p</i> < 0.05), including elevated cardiolipin (CL) and phosphatidylglycerol (PG), and reduced phosphatidylcholine (PC) and triglycerides (TG). ELISA confirmed these changes (<i>p</i> < 0.01 or <i>p</i> < 0.001), consistent with lipidomic findings. LY-OE showed significantly higher AtoB concentration during the logarithmic growth phase and exhibited higher ATP content during NP degradation. These findings suggest that <i>atoB</i> overexpression enhances NP degradation by both boosting energy supply and remodeling lipid metabolism. This work identifies <i>atoB</i> as a key factor for NP biodegradation and provides a promising strategy for developing high-performance bioremediation strains.