A novel Marinactinospora strain JX35-4T was isolated from red soil which was collected from Wushan, northern Jiangxi Province, China. Analysis of the 16S rRNA gene sequences showed that strain JX35-4T belongs to the genus Marinactinospora and formed a distinct phylogenetic clade with Marinactinospora thermotolerans SCSIO 00652T and Marinactinospora endophytica YIM 690053T with sequence similarity of 96.97% and 96.42%, respectively. The strain was Gram-positive and formed branched substrate hyphae with no fragmentation, and abundant aerial hyphae that differentiated into long spore chains, and short rod-shaped spores. Growth occurred at 20-45 °C, pH 7.0-12.0 and in the presence of 0-7.5% (w/v) NaCl. The genomic DNA G + C content was determined to be 68.3 mol%. The cell wall of strain JX35-4T contained meso-diaminopimelic acid and xylose. Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol mannosides and one unidentified phospholipid. The major fatty acids of strain JX35-4T consisted of anteiso-C17:0 and iso-C16:0. Major menaquinones were MK-9(H10), MK-12 and MK-10(H2). Based on the polyphasic data, strain JX35-4T (= CGMCC 4.7382T = DSM 104977T) is concluded to represent a novel species of the genus Marinactinospora, for which the name Marinactinospora rubrisoli sp. nov. is proposed.
Keywords: 16S rRNA gene; Marinactinospora rubrisoli sp. nov.; Polyphasic taxonomy; Red soil.