Nocardia lasii sp. nov., a novel actinomycete isolated from the cuticle of an ant (Lasius fuliginosus L).

Abstract

A novel actinomycete, designated strain 3C-HV12T, was isolated from the cuticle of an ant (Lasius fuliginosus L) and characterised using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain 3C-HV12T belongs to the genus Nocardia with high sequence similarities to Nocardia soli DSM 44488T (99.2%) and Nocardia cummidelens R89T (99.2%), and phylogenetically clustered with these two species and Nocardia ignorata DSM 44496T (98.8%), Nocardia salmonicida JCM 4826T (98.8%), Nocardia fluminea S1T (98.8%), Nocardia coubleae OFN N12T (98%) and Nocardia camponoti 1H-HV4T (97.4%). The morphological and chemotaxonomic properties of the strain are also consistent with those of members of the genus Nocardia. The strain was observed to form extensively branched substrate hyphae which fragmented into rod-shaped and non-motile elements. The cell wall was found to contain meso-diaminopimelic acid and the whole cell sugars were identified as arabinose and galactose. The predominant menaquinone was identified as MK-8(H4, ω-cycl). The phospholipid profile was found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as C18:0 10-methyl, C16:0 and C16:1ω7c. Mycolic acids were found to be present. A combination of DNA-DNA hybridisation experiments and phenotypic tests were carried out between strain 3C-HV12T and its phylogenetically closely related strains, which further clarified their relatedness and demonstrated that 3C-HV12T could be distinguished from these strains. Therefore, the strain is concluded to represent a novel species of the genus Nocardia, for which the name Nocardia lasii sp. nov. is proposed. The type strain is 3C-HV12T (=DSM 100525T=CGMCC 4.7279T).