Pseudonocardia broussonetiae sp. nov., an endophytic actinomycete isolated from the roots of Broussonetia papyrifera.

Abstract

A novel endophytic actinomycete, designated strain Gen 01T, was isolated from the roots of Broussonetia papyrifera and characterized by using a polyphasic approach. The predominant cellular fatty acids were iso-C16 : 0, summed feature 3, iso H-C16 : 1, C16 : 0 and iso-C14 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannosides, phospholipids of unknown structure containing glucosamine inositol, phosphatidylinositol and unidentified phospholipids. The major menaquinone was MK-8 (H4). The DNA G+C content of the genome sequence, consisting of 7 177 725 bp, was 74.5 mol%. Phylogenetic analysis of the full-length 16S rRNA gene sequences showed that strain Gen 01T belongs to the genus Pseudonocardia with the highest sequence similarity to Pseudonocardia petroleophila CGMCC 4.1532T (98.9 %) and lower than 98.7 % similarity to other species of the genus Pseudonocardia with validly published names. The average nucleotide identity and digital DNA-DNAhybridization values between strain Gen 01T and P. petroleophila CGMCC 4.1532T were 84.6 and 30.9 %, respectively. Furthermore, the morphological, physiological and biochemical characteristics were sufficient to categorize strain Gen 01T as being distinct from P. petroleophila CGMCC 4.1532T. Consequently, based on phenotypic and genotypic characteristics, strain Gen 01T represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia broussonetiae sp. nov. is proposed. The type strain is Gen 01T (=CICC 24820T=JCM 33840T).