A novel actinomycete, designated strain NEAU-TCZ24T, was isolated from soil and characterized using a polyphasic approach. The results of phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Cellulomonas and formed a stable clade with its closest relatives Cellulomonas terrae JCM 14899T (98.4 % 16S rRNA gene sequence similarity), Cellulomonas xylanilytica JCM 14281T (97.9 %) and Cellulomonas humilata JCM 11945T (97.7 %). The major menaquinones were identified as MK-9(H4) and MK-8(H4). The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositolmannoside, a ninhydrin-positiveglycolipid, an unidentified phosphoglycolipid, an unidentified phospholipid and an unidentified lipid. The major fatty acids were identified as anteiso-C15 : 0, C18 : 1ω9c, C16 : 0 and anteiso-C17 : 0. Moreover, morphological and chemotaxonomic properties of NEAU-TCZ24T also confirmed the affiliation of the isolate to the genus Cellulomonas. However, multilocus sequence analysis based on five other house-keeping genes (gyrB, rpoB, recA, relA and atpD), DNA-DNA relatedness, physiological and biochemical data indicated that NEAU-TCZ24T could be distinguished from its closest relatives. Therefore, it is proposed that NEAU-TCZ24T represents a novel species of the genus Cellulomonas, for which the name Cellulomonas rhizosphaerae sp. nov. is proposed. The type strain is NEAU-TCZ24T (=CCTCC AA 2018042T=JCM 32383T).
Keywords: 16S rRNA gene; Cellulomonas rhizosphaerae sp. nov.; polyphasic taxonomy.