Actinomycetospora rhizophila sp. nov., an actinomycete isolated from rhizosphere soil of a peace lily (Spathi phyllum Kochii)

Abstract

A novel actinomycete, designated strain NEAU-B-8T, was isolated from the rhizosphere soil of a peace lily (Spathi phyllum Kochii) collected from Heilongjiang province, north-east China. Key morphological and physiological characteristics as well as chemotaxonomic features of strain NEAU-B-8T were congruent with the description of the genus Actinomycetospora , such as the major fatty acids, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. The 16S rRNA gene sequence analysis revealed that strain NEAU-B-8T shared the highest sequence similarities with Actinomycetospora lutea JCM 17982T (99.3 % 16S rRNA gene sequence similarity), Actinomycetospora chlora TT07I-57T (98.4 %), Actinomycetospora straminea IY07-55T (98.3 %) and Actinomycetospora chibensis TT04-21T (98.2 %); similarities to type strains of other species of this genus were lower than 98 %. The phylogenetic tree based on 16S rRNA gene sequences showed that strain NEAU-B-8T formed a distinct branch with A. lutea JCM 17982T that was supported by a high bootstrap value of 97 % in the neighbour-joining tree and was also recovered with the maximum-likelihood algorithm. However, the DNA–DNA relatedness between strain NEAU-B-8T and A. lutea JCM 17982T was found to be 50.6±1.2 %. Meanwhile, strain NEAU-B-8T differs from other most closely related strains in phenotypic properties, such as maximum NaCl tolerance, hydrolysis of aesculin and decomposition of urea. On the basis of the morphological, physiological, chemotaxonomic, phylogenetic and DNA–DNA hybridization data, we conclude that strain NEAU-B-8T represents a novel species of the genus Actinomycetospora , named Actinomycetospora rhizophila sp. nov. The type strain is NEAU-B-8T. ( = CGMCC 4.7134T = DSM 46673T).