Deciphering the cytochrome P450 genes in the microbiome of a chronically polluted soil with history of agricultural activities

Abstract

Background Cytochrome P450 monooxygenases (CYPs) are exciting biocatalysts that catalyzes diverse regio- and stereoselective reactions of a broad range of substrates. The cytochrome P450 genes (CYPomes) of a chronically polluted soil (3S) with history of agricultural activities were deciphered via functional annotation of putative ORFs (open reading frames) using KEGG KofamKOALA, PHMMER, the Cytochrome P450 Engineering Database CYPED v6.0, and the NCBI Batch Web CD-Search tool. Results Annotation revealed the detection of seventy-seven CYP families and eight standalone CYPs cutting across the three domains of life. The prokaryote CYPome has 72 CYP families, 93 subfamilies, and seven standalone CYPs. The phylum Proteobacteria and the genera Streptomyces, Mycobacterium, and Bacillus with 17, 16, 24, and 5 CYP families were predominant, while the domain Archaea was represented by CYP119A1. The phylum Cyanobacteria has two families, while 23 actinobacterial CYPs (other than Streptomyces and Mycobacterium) were also detected. The detected prokaryote CYPs are responsible for biodegradation of camphor, hydroxylation of monoterpene alcohols, biosynthesis of secondary metabolites, and hydroxylation of fatty acids and steroidal compounds. The eukaryote CYPome was represented by seven fungal CYPs (CYP505A3, CYP505B1, CYP51A, CYP51C, CYP55A1, CYP55A2, and CYP55A3) from Acremonium egyptiacum, Fusarium oxysporum, Aspergillus oryzae, Gibberella moniliformis, Aspergillus flavus, and Fusarium lichenicola, respectively, and CYP524A1 from the slime mold, Dictyostelium discoideum. The fungi CYPs were involved in biosynthesis of secondary metabolites, hydroxylation of fatty acids, and nitrate reduction and denitrification. Conclusions This study has established the diverse roles played by CYPs in soil, its implication for soil health and resilience, and its potentials for industrial application.