Taxonomic and Genomic Characterization of Niveibacterium terrae sp. nov., a New Species from Riparian Soil in the Seomjin River, Republic of Korea

A novel Gram stain-negative, rod-shaped, non-motile bacterium, designated strain 24SJ04S-2T, was isolated from riparian soil near the Seomjin River, Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain 24SJ04S-2T within the genus Niveibacterium in the family Zoogloeaceae, with high similarity to Niveibacterium umoris (97.3%) and Niveibacterium microcysteis (96.7%). Whole-genome sequencing revealed a genome size of 3.98 Mbp with a G+C content of 63.9 mol%, and genomic relatedness metrics confirmed that strain 24SJ04S-2T represents a novel species. The strain demonstrated unique growth characteristics, including tolerance to low salinity and a broad pH range (5.0 to 10.0), suggesting ecological adaptability to fluctuating riparian environments. Chemotaxonomic analysis identified ubiquinone-8 as the major quinone, with diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine as dominant polar lipids. Fatty acid profiling showed that summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C16:0 were predominant. Genome analysis identified several biosynthetic gene clusters, including those potentially associated with antimicrobial and antioxidant compounds. Based on its distinct genomic and phenotypic characteristics, we propose the designation Niveibacterium terrae sp. nov. This discovery highlights the potential ecological and biotechnological roles of Niveibacterium terrae in nutrient cycling and environmental remediation in freshwater ecosystems. The type strain is 24SJ04S-2T (=KACC 23837T =FBCC-B16161T).