| Summary: | <i>Ralstonia solanacearum</i> is a major phytopathogenic bacterium that attacks many crops and other plants around the world. In this study, a novel actinomycete, designated strain NEAU-SSA 1<sup>T</sup>, which exhibited antibacterial activity against <i>Ralstonia solanacearum</i>, was isolated from soil collected from Mount Song and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with those of the genus <i>Streptomyces</i>. The 16S rRNA gene sequence analysis showed that the isolate was most closely related to <i>Streptomyces aureoverticillatus</i> JCM 4347<sup>T</sup> (97.9%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a cluster with <i>Streptomyces vastus</i> JCM4524<sup>T</sup> (97.4%), <i>S. cinereus</i> DSM43033<sup>T</sup> (97.2%), <i>S. xiangluensis</i> NEAU-LA29<sup>T</sup> (97.1%) and <i>S. flaveus</i> JCM3035<sup>T</sup> (97.1%). The cell wall contained <i>LL</i>-diaminopimelic acid and the whole-cell hydrolysates were ribose, mannose and galactose. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), hydroxy-phosphatidylethanolamine (OH-PE), phosphatidylinositol (PI), two phosphatidylinositol mannosides (PIMs) and an unidentified phospholipid (PL). The menaquinones were MK-9(H<sub>4</sub>), MK-9(H<sub>6</sub>), and MK-9(H<sub>8</sub>). The major fatty acids were <i>iso</i>-C<sub>17:0</sub>, C<sub>16:0</sub> and C<sub>17:1</sub> ω9c. The DNA G+C content was 69.9 mol %. However, multilocus sequence analysis (MLSA) based on five other house-keeping genes (<i>atp</i>D, <i>gyr</i>B, <i>rec</i>A, <i>rpo</i>B, and <i>trp</i>B), DNA−DNA relatedness, and physiological and biochemical data showed that the strain could be distinguished from its closest relatives. Therefore, it is proposed that strain NEAU-SSA 1<sup>T</sup> should be classified as representatives of a novel species of the genus <i>Streptomyces</i>, for which the name <i>Streptomyces sporangiiformans</i> sp. nov. is proposed. The type strain is NEAU-SSA 1<sup>T</sup> (=CCTCC AA 2017028<sup>T</sup> = DSM 105692<sup>T</sup>).
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