Genome-Resolved Delineation of Three Novel Endophytic Achromobacter Species from Desert Medicinal Plants

Endophytic bacteria from plants adapted to arid and semi-arid environments represent an underexplored reservoir of microbial diversity with potential agricultural applications. Here, we report a polyphasic taxonomic and genome-based characterization of Achromobacter sp. isolates recovered from root and foliar tissues of Citrullus colocynthis and Peganum harmala, two medicinal plants thriving under harsh environmental conditions. Whole-genome sequencing, phylogenomic analyses, average nucleotide identity (ANI), digital DNA–DNA hybridization (dDDH), multilocus sequence typing, and detailed phenotypic profiling revealed three previously undescribed species, for which we propose the names Achromobacter colocynthi sp. nov., Achromobacter maghribensis sp. nov., and Achromobacter semiaridum sp. nov. Genome assemblies were highly complete (98.7–99.2%) with minimal contamination (