Bacillus cereus GW-01 inoculation reduces pyrethroid residues and improves quality of Sichuan Paocai by changing the metabolic profile of fermentation

Pyrethroid residues in vegetables pose a challenge for household food processing. This study introduced Bacillus cereus GW-01, a pyrethroid-degrading bacterium, into Sichuan Paocai (SCP) fermentation. The study investigated the reduction of β-cypermethrin (β-CY), fenpropathrin (FNP), and λ-cyhalothrin (LCT) residues, alterations in metabolic profiles, and shifts in bacterial communities. Over fermentation, concentrations of β-CY, FNP, and LCT decreased. Notably, compared to the control, GW-01 proliferated in SCP, and the sample with GW-01 exhibited an enhanced degradation of β-CY, FNP, and LCT by 26.14%, 36.32%, and 33.70%, respectively. GW-01 presence lead to significant increases in volatile flavor components (VFC), organic acids (OA) including tartaric acid and succinic acid, and free amino acids (FAA) including Asn, Glu, Lys, and Pro after 7 days. The relative abundance of Bacillus in the group inoculated with GW-01 was higher than control, and the probiotics including Leuconostoc, Latilactobacillus, Brochothrix, Weissella, Lactobacillus, and Lactococcus, experienced a remarkable upsurge, reaching their zenith on the 7th day. Compared to CK, intriguing pathways such as bacterial chemotaxis, benzoic acid family, and mineral adsorption were additionally enriched in groups exposed to GW-01 and pyrethroids. The study's aim is to provide insights for reducing pesticide residues and enhancing fermented food quality.