Genome-wide analyses provide insights into genetic variation, phylo- and co-phylogenetic relationships, and biogeography of the entomopathogenic nematode genus Heterorhabditis.

Multigene, genus-wide phylogenetic studies have uncovered the limited taxonomic resolution power of commonly used gene markers, particularly of rRNA genes, to discriminate closely related species of the nematode genus Heterorhabditis. In addition, conflicting tree topologies are often obtained using the different gene markers, which limits our understanding of the phylo- and co-phylogenetic relationships and biogeography of the entomopathogenic nematode genus Heterorhabditis. Here we carried out phylogenomic reconstructions using whole nuclear and mitochondrial genomes, and whole ribosomal operon sequences, as well as multiple phylogenetic reconstructions using various single nuclear and mitochondrial genes.

Bacterial bioluminescence is an important regulator of multitrophic interactions in the soil.

Enormous efforts have been made to understand the functions of bioluminescence; however, its relevance in soil ecosystems has barely been investigated. In addition, our understanding of the biological relevance of bioluminescence is hampered by the scarcity of tools to genetically manipulate this trait. Using the symbionts of entomopathogenic nematodes, Photorhabdus bacteria, we show that bioluminescence plays important regulatory roles in multitrophic interactions in the soil.

Xenorhabdus aichiensis sp. nov., Xenorhabdus anantnagensis sp. nov., and Xenorhabdus yunnanensis sp. nov., Isolated from Steinernema Entomopathogenic Nematodes.

Three bacterial strains, XENO-2, XENO-7, and XENO-10, isolated from Steinernema entomopathogenic nematodes, were found to represent novel Xenorhabdus species. In this study, we describe these new species by whole-genome and whole-proteome phylogenomic reconstructions, by calculating sequence identity scores using core genome sequences, and by phenotypic characterization. Phylogenomic reconstructions using ribosomal and house-keeping genes, and whole-genome and whole-proteome sequences show that XENO-2 and XENO-10 are closely related to Xenorhabdus japonica DSM 16522 and that XENO-7 is closely related to Xenorhabdus bovienii subsp.

sp. nov. and subsp. subsp. nov., isolated from entomopathogenic nematodes.

Six Gram-negative, rod-shaped bacterial strains isolated from entomopathogenic nematodes were characterized to determine their taxonomic position. 16S rRNA and gene sequences indicate that they belong to the class , family and genus , and that some of them are conspecifics. Two of them, APURE and JAR, were selected for further molecular characterization using whole genome- and whole-proteome-based phylogenetic reconstructions and sequence comparisons.

sp. nov., the symbiotic bacterium associated with the entomopathogenic nematode .

is a symbiotic group of bacteria associated with entomopathogenic nematodes of the family Steinernematidae. Although the described species list is extensive, not all their symbiotic bacteria have been identified. One single motile, Gram-negative and non-spore-forming rod-shaped symbiotic bacterium, strain VLS, was isolated from the entomopathogenic nematode .

Soil texture, infective juvenile concentration, and soil organic matter influence the efficacy of isolate Lican Ray.

The influence of infective juveniles (IJs) concentration, soil texture, IJ-host distance and organic matter (OM) content, at different decomposition degree, on the activity of the nematode isolate Lican Ray (LR) was examined using larvae. Bioassays were conducted in tubes of varied length, filled with soil of different textures, placed either vertically or horizontally. In the concentration assay, highest IJ concentrations caused maximum larval mortality in all soil types (440, 2,200 and 4,400 IJs in clay, loam and sandy loam).