Single-strain species descriptions (SSSD) are becoming increasingly important in microbial ecology and systematics reflecting the realities of modern microbial discovery. However, SSSD are discouraged by the International Journal of Systematic and Evolutionary Microbiology, the official journal of the International Committee on Systematics of Prokaryotes (ICSP) as of writing of this manuscript on 18th December 2025 (https://www.microbiologyresearch.org/content/journal/ijsem?page=about-journal). The committee also formulates rules of the International Code of Nomenclature of Prokaryotes (ICNP). Under the ICNP Rule 30(3b) for each Type strain to be considered valid, it must be deposited in two international repositories from where it must be available without any restrictions (Oren et al., 2023). This has created legal and practical barriers in many biodiversity-rich countries, such as India (Rahi, 2021) and South Africa (van Lill et al., 2024) which follow stricter biodiversity protection laws. The recently published Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode) provides a forward-looking alternative that enables rigorous, legally compliant recognition of SSSD without requiring transboundary transfer of biological material (Hedlund et al., 2022). The SeqCode allows genome sequences as well cultivated strains as legitimate sources of nomenclatural types, thereby enabling researchers from such countries to describe novel taxa. The overall goal of this study was to describe and name a novel taxon based on a single strain isolated from the silkworm, Bombyx mori L. using the SeqCode.Stenotrophomonas is a genus of Gram-negative, flagellated, chemo-organotrophic γ-proteobacteria capable of both aerobic and facultative anaerobic growth. Members of this genus have been isolated from diverse ecological niches including blood, soil, water, and plants, reflecting its ecological versatility (Assih et al., 2002; Li et al., 2024). The genus is also placed in a taxonomically heterogeneous group characterized by broad ecological adaptability. Historically, the genus underwent several modifications before its formal creation in 1993. The type species, Stenotrophomonas maltophilia, which was isolated from human pleural fluid in 1943, was originally designated as Bacterium bookerii. It was subsequently validly described as Pseudomonas maltophilia (Hugh and Ryschenkow, 1961). Later, based on quinone profiling, cellular fatty acid composition, enzymatic properties, and genotypic studies (DNA-rRNA and DNA-DNA hybridization, G + C content), the species was reclassified as Xanthomonas maltophilia (Swings et al., 1983). However, the taxonomic placement of P. maltophilia within the genus Xanthomonas was met with considerable criticism (van Zyl and Steyn, 1992). To resolve these inconsistencies, Palleroni and Bradbury (1993) proposed its reclassification as the Type species of Stenotrophomonas gen. Nov. As of 18th December 2025, the genus is represented by 27 distinct species. Although there are 29 species validly published under the ICNP and listed on the List of Prokaryotic Names with Standing in Nomenclature (LPSN, https://lpsn.dsmz.de), two of these are synonyms. Importantly, S. maltophilia is the most extensively studied species. It is an opportunistic pathogen in nosocomial infections, whereas other species have demonstrated plant growth-promoting effects, roles in bioremediation, and the capacity to produce bioactive metabolites (Mukherjee and Roy, 2016; Said et al., 2023). In addition, two novel species, S. mexicanensis and S. veracruzanensis which belong to the S. maltophilia complex (Smc) have been recently proposed, but they have not been validly published yet under the ICNP (Ortiz Álvarez et al., 2025). Effectively, there are only 27 validly published species in the genus and the focus of the manuscript therefore remains on these.

In the present study, we report the isolation of a novel strain RAC2TS from the hemolymph of Bombyx mori L. By integrating phenotypic, chemotaxonomic, and whole-genome analyses, we propose this isolate as a new species within the genus Stenotrophomonas, designated as S. raiganjensis RAC2TS. Our study findings expand the current knowledge of the ecological distribution and potential pathogenic relevance of Stenotrophomonas, particularly within the insect-associated environments for the first time.