CodY constrains β-cypermethrin degradation by regulating physiological adaptation and soil ecological performance in Bacillus cereus GW-01

β-cypermethrin (β-CY) is a widely used pyrethroid insecticide, yet the regulatory mechanisms that determine microbial degradation efficiency remain unclear. Here, we examined the role of the global nutrient-responsive regulator CodY in β-CY degradation by Bacillus cereus GW-01 using a wild-type strain, an in-frame codY deletion mutant, and a complemented strain. Loss of codY shortened the growth lag phase under β-CY stress and accelerated β-CY removal across 50–200 mg/L, reducing the apparent half-life from 3.61 to 12.62 d in the wild type to 2.42–9.61 d in Δ codY . Complementation largely restored the wild-type phenotype, confirming CodY as a negative regulator of β-CY dissipation. Transcriptomic and physiological analyses showed that Δ codY reallocated cellular functions toward branched-chain amino acid metabolism, transport, redox adjustment, envelope remodeling, adhesion, and biofilm formation. Consistently, the mutant exhibited higher cell-surface hydrophobicity, stronger auto-aggregation, enhanced biofilm formation, increased superoxide dismutase (SOD) activity, and lower lipid peroxidation. In soil microcosms, Δ codY also outperformed the wild type in both non-sterilized and sterilized soils, shortening β-CY half-lives by 13.5% and 22.8%, respectively. Community profiling further showed that Δ codY altered bacterial and fungal succession during remediation, with stronger early selection, later bacterial richness recovery, and a more modular co-occurrence network. These results show that CodY restricts β-CY degradation by constraining both catabolic readiness and surface-associated stress adaptation. Targeting global regulatory nodes may therefore improve microbial remediation of hydrophobic pesticide residues in soil.