Agromyces tardus sp. nov., an actinobacterium isolated from the rhizosphere soil of wheat (Triticum aestivum L.)

A Gram-stain-positive, aerobic, heterotrophic, non-spore-forming and rod-shaped strain, designated SJ-23 T , was isolated from rhizosphere soil of wheat ( Triticum aestivum L.) collected from Langfang, Hebei Province, central PR China and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics were consistent with those of members of the genus Agromyces . The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, glycolipid and three unidentified lipids. The predominant menaquinones detected were MK-12, MK-11 and MK-10. Major fatty acids were identified as anteiso-C 17 : 0 , anteiso-C 15 : 0 and iso-C 16 : 0 . The 16S rRNA gene sequence analysis showed that strain SJ-23 T belongs to the genus Agromyces with high sequence similarities to Agromyces ramosus DSM 43045 T (99.2 %), Agromycescerinus subsp. cerinus DSM 8595 T (98.8 %) and Agromyces cerinus subsp. nitratus DSM 8596 T (98.6 %). Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a separate branch in the genus Agromyces . Furthermore, the combination of DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain SJ-23 T could be distinguished from its closest relatives. Therefore, it is proposed that strain SJ-23 T represents a novel species of the genus Agromyces , for which the name Agromycestardus sp. nov. is proposed. The type strain is SJ-23 T (=CGMCC 4.7419 T =DSM 105049 T ).