Nocardia acidivorans sp. nov., isolated from soil of the island of Stromboli

Abstract

A Gram-positive, non-spore-forming bacterium (strain GW4-1778T) was isolated from soil of the Italian island of Stromboli. 16S rRNA gene sequence similarity studies showed that strain GW4-1778T is a member of the genus Nocardia, most closely related to Nocardia pseudobrasiliensis (GenBank accession no. DQ659914; 98.6 %), Nocardia nova (Z36930; 98.6 %), Nocardia niigatensis (AB092563; 98.4 %), Nocardia jiangxiensis (AY639902; 98.0 %), Nocardia uniformis (Z46752; 98.0 %) and Nocardia miyunensis (AY639901; 97.8 %). Strain GW4-1778T could be distinguished from any other established Nocardia species by sequence similarity values of less than 97.5 %. Strain GW4-1778T exhibited a quinone system with the predominant compound MK-8 (H4, ω-cycl) (99.5 %) and traces of MK-8 (H4), characteristic for the genus Nocardia. The polar lipid profile of strain GW4-1778T consisted of the predominant compound diphosphatidylglycerol, moderate amounts of phosphatidylethanolamine, phosphatidylinositol, two phosphatidylinositol mannosides, a unknown polar lipid and trace amounts of two unknown lipids and the major fatty acids were C15 : 0, C16 : 0, C17 : 1 ω8c and 10-methyl C17 : 0. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain GW4-1778T from related species with 16S rRNA gene similarities of >97.5 %. Therefore, strain GW4-1778T merits species status, for which the name Nocardia acidivorans sp. nov. is proposed, with the type strain GW4-1778T (=CCUG 53410T=CIP 109315T=DSM 45049T).