Description of Sphingobium wonjuense sp. nov. isolated from mountain soil and Sphingobium erigeronicola sp. nov. isolated from plant root

Two novel bacterial strains designated CR2-8^T and HWE2-09^T were isolated from mountain soil and plant root, respectively, and characterized using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CR2-8^T shared the highest sequence similarity with <i>Sphingobium limneticum</i> 301^T (98.0%), and HWE2-09^T with <i>Sphingobium rhizovicinum</i> CC-FH12-1^T (97.8%). The genome-based comparison indicated that both CR2-8^T and HWE2-09^T shared the highest relatedness with <i>Sphingobium cupriresistens</i> CU4^T, sharing 84.05% and 84.7 % orthologous average nucleotide identity and 29.3% and 30.3 % digital DNA-DNA hybridization, respectively, all of which were clearly below the suggested cutoffs for species distinction. For both strains, the major fatty acids were two summed features, one consisting of C_{16 : 1} ω7c and/or C_{16 : 1} ω6c and the other consisting of C_{18 : 1} ω7c and/or C_{18 : 1} ω6c, and also C_{14 : 0} 2OH and C_{16 : 0}. The major ubiquinone was Q-10, and the main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidyldimethylethanolamine for both strains. The DNA G+C content of strain CR2-8^T was 63.16 %, and that of strain HWE2-09^T was 63.26 %. The phenotypic, chemotaxonomic and phylogenetic analyses indicate that each of the strains CR2-8^T and HWE2-09^T should be classified as a new species of <i>Sphingobium</i>, for which the names <i>Sphingobium wonjuense</i> sp. nov. (type strain=CR2-8^T=KCTC 8939^T=JCM 36935^T) and <i>Sphingobium erigeronicola</i> sp. nov. (type strain=HWE2-09^T=KCTC 8940^T=JCM 36936^T) are proposed.