INTERNATIONAL JOURNAL OF SYSTEMATIC' BACTERIOLOGY, Oct. 1Y94, p. 608-61 1 Copyright 0 1994, International Union of Microbiological Societies OO20-7713/94/$O4.00+ 0 Vol. 44. No. 4 Transfer of Nocardioides fastidiosa Collins and Stackebrandt 1989 to the Genus Aeromicrobium as Aeromicrobium fastidiosum comb. nov. TOMOHIKO TAMURA" AND AKIRA YOKOTA Institute for Fermentation, Osaka, Yodoguwa-ku, Osaka 532, Japan The 16s rRNA sequences of aerobic LL-diaminopimelic acid-containing coryneform bacteria were compared, and the sequence of Nocurdioidesfustidiosu exhibited a high level of similarity to the sequence of Aeronticrobiurn erythreurn but not to the sequences of the other species of the genus Nocurdioides. Furthermore, analyses of nienaquinone systems and cellular fatty acids revealed that N.fustidiosu was similar to A. erythreurn but differed from the other Nocurdioides species. On the basis of chemotaxonomic data and DNA-DNA hybridization and comparative 16s rRNA results, we propose that N. fustidiosu should be transferred to the genus Aerornicrobiunt as Aerornicrobium fustidiosurn comb. nov. (type strain, IF0 14897). Miller et al. (9) described a nonmycelial, nonsporulating actinomycctc that produces the macrolide antibiotic erythro- mycin and named it Aci-omicrohium erythreum. This organism has LL-diaminopimelicacid (LL-DAP) as the diamino acid in its cell wall. In addition to the genus Aeromicrobium, workers have described two other genera of aerobic, LL-DAP-contain- ing coryneform and nocardioform bacteria, the genera Nocar- chides and Terrcrhocter. In the genus Nocardioides, there are currently five species: Nocardioides albus ( 12), Nocardioides simplex ( lo), Nocardioides luteus ( 13), Nocardioidesjensenii ( l), and Nocardioides fkstidiosa (4). Terrabucter tumescens (1) is the only species in the genus Terrabucter. In the course of our taxonomic study of LL-DAP-containing actinomycetes, N. fastidiosa was found to be more closely related to Aeromicrobium erythreunz than to the other Nocar- dioides species on the basis of the results of phylogenetic and c h em o t axonom ic an a 1 y se s. N. fustidiosa and A eromicrohium erjlthreum have the following characteristics in common: the major menaquinone is MK-9(H4); the major fatty acid is 10-methyloctadecanoic acid (lOMe C,, J; phosphatidyleth- anolamine is present; and the organisms require biotin and thiamine for growth. In this paper, we reclassib N. fustidiosa, and we propose that N. fastidiosa should be transferred to the genus Aeromicrohium as Aeromici-ohm fastidiosum comb. nov. ied by the photobiotin-microplate hybridization method of Ezaki et al. (5). Comparison of 16s rRNA sequences and nucleotide se- quence accession numbers. All sequence data were obtained from the DDBJ, EMBL, and GenBank nucleotide sequence databases, where the nucleotide sequences are available under the following accession numbers: M37200 (Aerornicwhiirm erythreum), M234 1 1 (Arthrobacterglohiformis), M38242 (Micw- coccus luteus), XS3211 (N. alhus). XS.3189 (N. jkstidiosti), XS3214 (N. Jensenii), X53212 (N. lriteirs), X72.377 (Sporiclitliyti polymorpha), X61478 (Streptomyces griseris). and X532 IS (T. tumescens). The nucleotide sequence of N. simplex was ob- tained from the study of Collins et al. (1). DNA sequences were aligned by using the ODEN system (7). Evolutionary distances were represented by using K,,,,, values as described by Kimura (8). A phylogenetic tree was constructed by the neighbor-joining method (14) from the K,,,,, values derived from the sequences. RESULTS AND DISCUSSION Phylogenetic analysis. The 16s rRNA sequencc of N. firstid- iosa exhibited a high level of relatedness (98.2%) with the 16s rRNA sequence of Aeromicrobium eiythrciim, based on ;I comparison of 1,260 nucleotides, and this valuc was higher MATERIALS AND METHODS Micrococcus luteus Bacterial strains and culture conditions. N. fastidiosa IF0 14897r ( T = type strain) and Aeromicrobium erythreum IF0 1S406T were obtained from the culture collection of the Institute for Fermentation, Osaka. For chemotaxonomic stud- ies these strains were grown in shaken cultures in nutrient broth (Difco Laboratories, Detroit, Mich.) at 28°C; and cells were harvested in the stationary phase, washed twice with water, and then freeze-dried. Chemical analyses. Preparation of peptidoglycan and anal- yses of cellular fatty acids, polar lipids, and isoprenoid quinones were carried out by previously described methods (16). DNA homology experiment. DNA-DNA homology was stud- ' Corresponding author. Mailing address: Institute for Ferrnenta- tion, Osaka. 17-85, Juso-honrnachi 2-chorne, Yodogawa-ku, Osaka 532, Japan. Phone: 06-300-6555. Fax: 06-300-68 14. Nocardioides fastidiosa )- Terrabacter tumescem Aeromicrobium erythreum Nocardwides jensenii Nocardioides simplex Nocardioides luteus A Sporichthya polymorpha h Nocardioides albus / ' Srreptomyces lividom Streptomyces grireus - 0.01 Knuc FIG. 1. Unrooted phylogenetic tree showing the positions of N. fustidiosa and some other actinornycete taxa. The tree is based on the results of a comparison of 1,260 bascs. 608