Taxonomic characterization of Kribbella broussonetiae sp. nov., a novel rare actinomycete isolated from the rhizosphere soil of Broussonetia papyrifera.

A novel rare actinomycete strain, WER1T, was isolated from rhizosphere soil of Broussonetia papyrifera collected from Xiangtan City, Hunan province, China. Strain WER1T contained LL-diaminopimelic acid as the diagnostic diamino acid in the peptidoglycan. The major fatty acids (>5%) were anteiso-C15:0, iso-C16:0, anteiso-C17:0 and summed feature 9 (iso-C17:1 ω9c and/or 10-methyl C16:0). The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, and phosphatidylinositol. Sequence analysis of 16S rRNA gene indicated that the strain belonged to the genus Kribbella and shared highest similarities to Kribbella karoonensis Q41T (99.57%), Kribbella speibonae YM55T (99.35%), Kribbella soli FMN22T (99.28%), Kribbella podocarpi YPL1T (99.14%), and Kribbella swartbergensis HMC25T (99.13%). Phylogenetic analysis based on 16S rRNA gene, five house-keeping genes (gyrB, rpoB, relA, recA, and atpD) and whole genome sequences showed that strain WER1T is closely related to K. karoonensis JCM 14304 T. But the average nucleotide identity and digital DNA-DNA hybridization values between strain WER1T and K. karoonensis JCM 14304 T were much less than the 95-96% and 70% cut-off points recommended for delineating species. In addition, phenotypic and chemotaxonomic characteristics further confirmed that strain WER1T represents a new Kribbella species, for which the name Kribbella broussonetiae sp. nov. ( = MCCC 1K10349T = KCTC 59685 T), is proposed.