Mumia spirodelae sp. nov., a novel actinobacterium isolated from greater duckweed (Spirodela polyrhiza)

An actinobacterial strain, designated DW29H23^T, was isolated from greater duckweed <i>Spirodela polyrhiza</i>. The strain was investigated using a polyphasic taxonomy approach. The comparison of the 16S rRNA gene sequence showed that strain DW29H23^T was most closely related to <i>Mumia xiangluensis</i> NEAU-KD1^T (99.2%) and <i>Mumia quercus</i> NEAU-365^T (98.9%). The average nucleotide identity and digital DNA-DNA hybridization values between the strain and closest type strains were below the threshold for species delineation. The strain was Gram-stain-positive, non-spore-forming and non-motile. Cells were irregular, rod-shaped. The whole-cell hydrolysates contained <i>ll</i>-diaminopimelic acid. The whole-cell sugars were glucose and ribose. The polar lipid profiles contained diphosphatidylglycerol, phosphatidylglycerol and three unidentified phospholipids. The major cellular fatty acids (>10%) were C_16:0, 10-methyl-C_18:0 and C_18:1 <i> ω</i>9<i>c</i>. The major menaquinone was MK-9(H₄). The G+C content was 71.7%. Genotypic, phenotypic and chemotaxonomic characterizations of strain DW29H23^T demonstrated that the strain represents a novel species of the genus <i>Mumia</i>, for which the name <i>Mumia spirodelae</i> sp. nov. is proposed. The type strain is DW29H23^T (=TBRC 18998^T=NBRC 116930^T).