Abstract
Deltamethrin is widely employed for crop pest control, aquaculture pond clearance, and fish parasite treatment. Due to its photostability, thermal resistance, and lipophilicity, deltamethrin has a high potential for environmental persistence and bioaccumulation in aquatic organisms. This poses significant risks to aquatic ecosystems, the safety of aquatic products, and human health. Although our previous study isolated Paracoccus sp. P-2 from crab culture pond sediment and demonstrated its high efficiency in degrading deltamethrin, the underlying mechanisms and enzyme characteristics remain unelucidated. In this study, genomic analysis revealed that the Paracoccus sp. P-2 genome was assembled into 3 contigs with a total length of 4,451,812 bp, an average G + C content of 67.73%, and a total of 4462 predicted genes. In addition, a quantitative analysis of the Paracoccus sp. P-2 proteome identified 3052 proteins, with 2705 exhibiting significant differential abundance (FC ≥ 1.5 or FC ≤ 0.6667, and p-value ≤ 0.05) following deltamethrin exposure. Among them, many upregulated differentially expressed proteins were enriched in carbohydrate and energy metabolism pathways, indicating that Paracoccus sp. P-2 enhances its basal metabolic activity in response to deltamethrin-induced stress. More importantly, enzymes belonging to hydrolases, decarboxylases, and those involved in multiple xenobiotic metabolic pathways were upregulated and are likely to participate in the degradation of deltamethrin. This study elucidates the impact of deltamethrin on bacterial metabolism and its degradation mechanism by Paracoccus sp. P-2, providing crucial insights and microbial resources for researching pyrethroid biodegradation.