Intrasporangium zincisolvens sp. nov., A Novel Actinobacterium Isolated from Rhizosphere Soil

A novel phosphate-solubilizing and zinc-solubilizing actinobacterium strain YIM S08009 T was isolated from rhizosphere soil collected from Pinus yunnanensis in Wuliangshan National Nature Reserve, Pu’er City, Yunnan Province, southwest PR China. Cells of strain YIM S08009 T were Gram-stain-positive, non-motile, irregular rods to cocci, and formed yellow and white colonies on nutrient agar. Growth was observed at 10–40 °C (optimum 25–35 °C), pH 6.0–8.5 (optimum 7), and 0–4% (w/v) NaCl (optimum 1%). The cell wall peptidoglycan contained LL -diaminopimelic acid. The whole-cell sugars were mannose, ribose, glucose, and galactose. The predominant menaquinone was MK-8(H 4 ). Major polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, unknown lipid, and 3 unknown phospholipids. The predominant fatty acids were iso -C 14:0 , iso -C 15:0, and iso -C 16:0 . The DNA G + C content was 72.6%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM S08009 T belonged to genus Intrasporangium , and was most closely related to Intrasporangium flavum MUSC 78 T , with 99.0% 16S rRNA gene sequence similarity. Strain YIM S08009 T shared 90.1% orthologous average nucleotide identity (OrthoANI) and 39.8% digital DNA-DNA hybridization (dDDH) with I. flavum MUSC 78 T . The genome of strain YIM S08009 T contained phosphate-solubilizing genes ( SenX3 , RegX3 , pstSCAB , ugpBAEC , phoA ) and zinc-solubilizing genes ( znuABC , zupT ), and the strain had also demonstrated in vitro phosphorus and zinc solubilization. Based on the genotypic and phenotypic analyses, strain YIM S08009 T (= CGMCC 1.60168 T = NBRC 116604 T = KCTC 59021 T ) represents a novel Intrasporangium species, for which the name Intrasporangium zincisolvens sp. nov. is proposed.