Nocardia macrotermitis sp. nov. and Nocardia aurantia sp. nov., isolated from the gut of the fungus-growing termite Macrotermes natalensis
René Benndorf, Jan W. Schwitalla, Karin Martin, Z. Wilhelm de Beer, John Vollmers, Anne‐Kristin Kaster, Michael Poulsen, Christine Beemelmanns
Abstract
The taxonomic positions of two novel aerobic, Gram-stain-positive Actinobacteria, designated RB20 T and RB56 T , were determined using a polyphasic approach. Both were isolated from the fungus-farming termite Macrotermes natalensis . Results of 16S rRNA gene sequence analysis revealed that both strains are members of the genus Nocardia with the closest phylogenetic neighbours Nocardia miyunensis JCM12860 T (98.9 %) and Nocardia nova DSM44481 T (98.5 %) for RB20 T and Nocardia takedensis DSM 44801 T (98.3 %), Nocardia pseudobrasiliensis DSM 44290 T (98.3 %) and Nocardia rayongensis JCM 19832 T (98.2 %) for RB56 T . Digital DNA–DNA hybridization (DDH) between RB20 T and N. miyunensis JCM12860 T and N. nova DSM 44481 T resulted in similarity values of 33.9 and 22.0 %, respectively. DDH between RB56 T and N. takedensis DSM44801 T and N. pseudobrasiliensis DSM44290 T showed similarity values of 20.7 and 22.3 %, respectively. In addition, wet-lab DDH between RB56 T and N. rayongensis JCM19832 T resulted in 10.2 % (14.5 %) similarity. Both strains showed morphological and chemotaxonomic features typical for the genus Nocardia , such as the presence of meso -diaminopimelic acid (A 2 pm) within the cell wall, arabinose and galactose as major sugar components within whole cell-wall hydrolysates, the presence of mycolic acids and major phospholipids (diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol), and the predominant menaquinone MK-8 (H 4 , ω-cyclo). The main fatty acids for both strains were hexadecanoic acid (C 16 : 0 ), 10-methyloctadecanoic acid (10-methyl C 18 : 0 ) and cis -9-octadecenoic acid (C 18 : 1 ω9 c ). We propose two novel species within the genus Nocardia : Nocardia macrotermitis sp. nov. with the type strain RB20 T (=VKM Ac-2841 T =NRRL B65541 T ) and Nocardia aurantia sp. nov. with the type strain RB56 T (=VKM Ac-2842 T =NRRL B65542 T ).