Abstract
A borrelidin-producing actinomycete, designated strain NEAU-W2(T), was isolated from the root surface of soybean [Glycine max (L.) Merr] and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of streptomycetes. The G+C content of the DNA was 66.12 mol%. Analysis of the 16S rRNA gene sequence of strain NEAU-W2(T) revealed that the strain formed a distinct clade within the 16S rRNA gene sequence phylogenetic tree and showed highest similarity (99.61 %) to Streptomyces neyagawaensis ATCC 27449(T). However, the DNA-DNA relatedness between strain NEAU-W2(T) and S. neyagawaensis ATCC 27449(T) was 58.51 %. Strain NEAU-W2(T) could also be differentiated from S. neyagawaensis ATCC 27449(T) and other Streptomyces species showing high 16S rRNA gene sequence similarity (98-99 %), as well as other borrelidin-producing strains, based on morphological and physiological characteristics. On the basis of its physiological and molecular properties, it is proposed that strain NEAU-W2(T) represents a novel Streptomyces species, Streptomyces heilongjiangensis sp. nov. The type strain is NEAU-W2(T) ( = CGMCC 4.7004(T) = ATCC BAA-2424(T) = DSM 42073(T)).