Comparative genomics of pesticide-degradingEnterococcussymbionts ofSpodoptera frugiperda(Lepidoptera: Noctuidae) leads to the identification of two new species and the reappraisal of insect-associatedEnterococcusspecies

Abstract

Enterococcusspecies have been described as core members of the microbial community ofSpodoptera frugiperda(Lepidoptera:Noctuidae) and have been reported in previous studies as insecticide degrading agents. Phenotypic assays and comparative genomics analyses of several pesticide-degradingEnterococcusisolated from the larval gut ofS. frugiperdaled to the identification ofEnterococcus entomosociumn. sp. andEnterococcus spodopteracolusn. sp. Their identities as new species were confirmed by whole genome alignment using the cut-offs of 95-96% for the average nucleotide identity (ANI) and 70% for the digital DNA:DNA hybridization (dDDH) values. The systematic positioning of these new species within the genusEnterococcuswas resolved using genome-based analysis, placingEnterococcus casseliflavusas the sister group ofE. entomosociumn. sp., andEnterococcus mundtiiofE. spodopteracolusn. sp. Comparative genomic analyses of several isolates ofE. entomosociumn. sp. andE. spodopteracolusn. sp. led to a better assessment of the interactions established in the symbiotic association withS. frugiperda, and the discovery of misidentified new species ofEnterococcusassociated with insects. Our analyses also indicated the potential ofE. entomosociumn. sp. AndE. spodopteracolusn. sp. to metabolize different pesticides arises from molecular mechanisms that result in the rapid evolution of new phenotypes in response to environmental stressors; in this case, the pesticides their host insect is exposed to.