Luiz de Queiroz College of Agriculture, Department of Entomology and Acarology, Insect Interactions Laboratory, University of São Paulo, Piracicaba, São Paulo, Brazil.
Microb Ecol. 2023 Nov;86(4):2583-2605. doi: 10.1007/s00248-023-02264-0. Epub 2023 Jul 11.
Enterococcus species have been described as core members of the microbial community of Spodoptera frugiperda (Lepidoptera: Noctuidae) and have been previously reported as insecticide degrading agents. This study aimed to investigate the molecular composition of these microbial symbionts of S. frugiperda to better understand their association with the host and their potential for insecticide metabolization. Through phenotypic assays and comparative genomic analyses of several pesticide-degrading Enterococcus isolated from the gut of S. frugiperda larvae, we identified two new species: Enterococcus entomosocium n. sp. and Enterococcus spodopteracolus n. sp. Their identities as new species were confirmed by whole genome alignment, utilizing 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 genus Enterococcus was resolved using genome-based analysis, revealing Enterococcus casseliflavus as a sister group of E. entomosocium n. sp., and Enterococcus mundtii as a sister group of E. spodopteracolus n. sp. Comparative genomic analyses of several isolates of E. entomosocium n. sp. and E. spodopteracolus n. sp. provided a better assessment of the interactions established in the symbiotic association with S. frugiperda and led to the discovery of misidentified new species of Enterococcus associated with insects. Our analyses indicated that the potential of E. entomosocium n. sp. and E. spodopteracolus n. sp. to metabolize different pesticides arises from molecular mechanisms that result in rapid evolution of new phenotypes in response to environmental stressors, in this case, the pesticides their host insect is exposed to.
已将肠球菌物种描述为夜蛾科（鳞翅目）斜纹夜蛾微生物群落的核心成员，并且先前曾被报道为杀虫剂降解剂。本研究旨在研究斜纹夜蛾肠道中这些微生物共生体的分子组成，以更好地了解它们与宿主的联系及其对杀虫剂代谢的潜力。通过对几种从斜纹夜蛾幼虫肠道中分离出的具有农药降解能力的肠球菌进行表型分析和比较基因组分析，我们鉴定出了两个新物种：昆虫肠球菌（Enterococcus entomosocium）和斜纹夜蛾肠球菌（Enterococcus spodopteracolus）。通过全基因组比对，利用平均核苷酸同一性（ANI）的 95-96%和数字 DNA：DNA 杂交（dDDH）值的 70%作为cut-offs，确认了它们是新物种。利用基于基因组的分析确定了这些新物种在肠球菌属中的系统定位，结果显示昆虫肠球菌与 E. casseliflavus 是姐妹群，斜纹夜蛾肠球菌与 E. mundtii 是姐妹群。对几种昆虫肠球菌和斜纹夜蛾肠球菌的比较基因组分析，提供了对与斜纹夜蛾共生关系中建立的相互作用的更好评估，并导致发现了与昆虫相关的被错误鉴定的新肠球菌物种。我们的分析表明，昆虫肠球菌和斜纹夜蛾肠球菌代谢不同杀虫剂的潜力来自分子机制，这些机制导致新表型的快速进化，以应对环境胁迫，在这种情况下，是其宿主昆虫接触到的杀虫剂。
