Actinocorallia populi sp. nov., an endophytic actinomycete isolated from a root of Populus adenopoda (Maxim.)

An endophytic actinobacterium, strain A251 T , was isolated from the root of Populus adenopoda Maxim and subjected to characterization using polyphasic taxonomy. Analysis of the 16S rRNA gene sequence revealed that the isolate represented a member of the phylogenetic cluster of the genus Actinocorallia and was most closely related to Actinocorallia aurantiaca JCM 8201 T (98.0 %) and Actinocorallia libanotica IFO 10495 T (98.0 %). DNA-DNA hybridization values between A251 T and these strains were 41.2 % and 45.0 %, respectively. The G+C content of the DNA was 71.5 mol%. Major fatty acids were C16 : 0, C16 : 1ω7c and C18 : 1ω9c. The peptidoglycan diamino acid of A251 T was meso-diaminopimelic acid and the whole-cell hydrolysates contained glucose and ribose. The major menaquinones were MK-9(H4) and MK-9(H6). The phospholipid profile included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, an undefined aminophospholipid and two undefined phospholipids. DNA-DNA hybridization data in combination with differences in the biochemical and physiological properties, indicated that A251 T should be classified as representing a novel species within the genus Actinocorallia, for which the name Actinocorallia populi sp. nov. is proposed, with A251 T (=CGMCC 4.7421 T =JCM 32178 T ) as the type strain.