Pseudonocardia tetrahydrofuranoxydans sp. nov. Peter Ka ¨ mpfer, 1 Ulrike Kohlweyer, 2 Barbara Thiemer 2 and Jan R. Andreesen 2 Correspondence Peter Ka ¨ mpfer peter.kaempfer@agrar. uni-giessen.de 1 Institut fu ¨ r Angewandte Mikrobiologie, Justus-Liebig-Universita ¨ t Giessen, Heinrich-Buff-Ring 26–32, D-35392 Giessen, Germany 2 Institut fu ¨ r Mikrobiologie, Martin-Luther-Universita ¨ t Halle, D-06099 Halle, Germany A Gram-positive, rod-shaped, non-endospore-forming but mycelium-forming actinobacterium (strain K1 T ) was isolated from an enrichment culture containing tetrahydrofuran (THF) as the sole source of carbon. On the basis of its G+C content (71?3 mol%) and of 16S rRNA gene sequence similarity studies, strain K1 T was shown to belong to the family Pseudonocardiaceae, most closely related to Pseudonocardia hydrocarbonoxydans (99?3 %), P. benzenivorans (98?8 %) and P. sulfidoxydans (98?3 %). The 16S rRNA gene sequence similarity to other Pseudonocardia species was less than 97 %. Chemotaxonomic data [major menaquinone MK-8(H 4 ); major fatty acids C 16 : 0 iso, C 15 : 0 iso and C 17 : 1 v6c] supported the affiliation of strain K1 T to the genus Pseudonocardia. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain K1 T from the three species P. benzenivorans, P. sulfidoxydans and P. hydrocarbonoxydans, although all four organisms utilized THF. Strain K1 T represents a novel species, for which the name Pseudonocardia tetrahydrofuranoxydans sp. nov. is proposed, with the type strain K1 T (=DSM 44239 T =CIP 109050 T ). The genus Pseudonocardia was originally proposed by Henssen (1957) for mycolateless nocardioform actino- mycetes with a type IV cell wall and, on the basis of a detailed phylogenetic analysis, the genus comprises 20 species at present, listed by Huang et al. (2002), Lee et al. (2000, 2001, 2002, 2004), Ka ¨mpfer & Kroppenstedt (2004) and Liu et al. (2006). Strain K1 T was enriched and recovered on a selective medium containing tetrahydrofuran (THF) as the single carbon source from sludge from a wastewater plant in Go ¨ttingen, Germany (Kohlweyer et al., 2000). Morphological properties, Gram-staining, acid- and alcohol-fastness were examined as described by Kohlweyer et al. (2000). Cell morphology was observed by phase- contrast microscopy. Determination of DNA G+C content (71?3 mol%) and amplification by PCR of the DNA encoding the 16S rRNA were performed as described by Kohlweyer et al. (2000). Phylogenetic analysis was per- formed using the software package MEGA version 2.1 (Kumar et al., 2001) after multiple alignment of data by CLUSTAL X (Thompson et al., 1997). Distances were deter- mined (distance options according to the Kimura-2 model) and clustering with the neighbour-joining (Fig. 1) and maximum-parsimony (Supplementary Fig. S1 in IJSEM Online) methods was performed by using bootstrap values based on 1000 replications. The 16S rRNA gene sequence of strain K1 T was a continuous stretch of 1440 bp. Sequence similarity calculations after neighbour-joining analysis indicated that the closest relatives of strain K1 T were Pseudonocardia hydrocarbonoxydans IMSNU 22140 T (99?3 %), Pseudonocardia sulfidoxydans DSM 44248 T (99?2 %) and Pseudonocardia benzenivorans B5 T (98?9 %). Lower sequence similarities were found to other species of the genus Pseudonocardia with validly published names. Results of chemotaxonomic analyses are given in the species description. Menaquinones were analysed as described by Kroppenstedt (1985) and fatty acids as described by Ka ¨mpfer & Kroppenstedt (1996). The quinone system sup- ports affiliation of K1 T to the genus Pseudonocardia, where all species have MK-8(H 4 ) as the major quinone (Warwick et al., 1994; McVeigh et al., 1994; Reichert et al., 1998; Huang et al., 2002; Ka ¨mpfer & Kroppenstedt, 2004). The fatty acid profile of strain K1 T was very similar to those of the closely related species P. sulfidoxydans, P. hydrocarbonoxydans and P. benzenivorans, and was congruent with the fatty acid profiles reported by Reichert et al. (1998). Abbreviation: THF, tetrahydrofuran. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain K1 T is AJ249200. A maximum-parsimony tree based on 16S rRNA gene sequences and details of the fatty acid composition of strain K1 T and related type strains are available as supplementary material in IJSEM Online. 64199 G 2006 IUMS Printed in Great Britain 1535 International Journal of Systematic and Evolutionary Microbiology (2006), 56, 1535–1538 DOI 10.1099/ijs.0.64199-0