AUTHOR=Chuang Shu-Cheng , Dobhal Shefali , Alvarez Anne M. , Arif Mohammad 

TITLE=Three new species, Xanthomonas hawaiiensis sp. nov., Stenotrophomonas aracearum sp. nov., and Stenotrophomonas oahuensis sp. nov., isolated from the Araceae family

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1356025

DOI=10.3389/fmicb.2024.1356025

ISSN=1664-302X

ABSTRACT=<p><italic>Xanthomonas</italic> and <italic>Stenotrophomonas</italic> are closely related genera in the family Lysobacteraceae. In our previous study of aroid-associated bacterial strains, most strains isolated from anthurium and other aroids were reclassified as <italic>X. phaseoli</italic> and other <italic>Xanthomonas</italic> species. However, two strains isolated from <italic>Spathiphyllum</italic> and <italic>Colocasia</italic> were phylogenetically distant from other strains in the <italic>Xanthomonas</italic> clade and two strains isolated from <italic>Anthurium</italic> clustered within the <italic>Stenotrophomonas</italic> clade. Phylogenetic trees based on 16S rRNA and nine housekeeping genes placed the former strains with the type strain of <italic>X. sacchari</italic> from sugarcane and the latter strains with the type strain of <italic>S. bentonitica</italic> from bentonite. In pairwise comparisons with type strains, the overall genomic relatedness indices required delineation of new species; digital DNA–DNA hybridization and average nucleotide identity values were lower than 70 and 95%, respectively. Hence, three new species are proposed: <italic>S. aracearum</italic> sp. nov. and <italic>S. oahuensis</italic> sp. nov. for two strains from anthurium and <italic>X. hawaiiensis</italic> sp. nov. for the strains from spathiphyllum and colocasia, respectively. The genome size of <italic>X. hawaiiensis</italic> sp. nov. is ~4.88 Mbp and higher than <italic>S. aracearum</italic> sp. nov. (4.33 Mbp) and <italic>S. oahuensis</italic> sp. nov. (4.68 Mbp). Gene content analysis revealed 425 and 576 core genes present in 40 xanthomonads and 25 stenotrophomonads, respectively. The average number of unique genes in <italic>Stenotrophomonas</italic> spp. was higher than in <italic>Xanthomonas</italic> spp., implying higher genetic diversity in <italic>Stenotrophomonas</italic>.</p>