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Based on the 16S rRNA sequences, DNA-DNA homology values, cellular lipid and fatty acid composition, and phenotypic characteristics, a new genus Burkholderia is proposed for the RNA homology group II of genus Pseudomonas. Seven species in this group were transferred to the new genus. Thus seven new combinations, Burkholderia cepacia (Palleroni and Holmes 1981), Burkholderia mallei (Zopf 1885), Burkholderia pseudomallei (Whitmore 1913), Burkholderia caryophylli (Burkholder 1942), Burkholderia gladioli (Severini 1913), Burkholderia pickettii (Ralston et al 1973) and Burkholderia solanacearum (Smith 1896) were proposed.

Based on the partial nucleotide sequence analysis of 16S ribosomal ribonucleic acid (rRNA), presence of unique sphingoglycolipids in cellular lipid, and the major type of ubiquinone (Q10), we propose Sphingomonas gen. nov. with the type species Sphingomonas paucimobilis (Holmes et al, 1977) comb. nov. From the homology values of deoxyribonucleic acid-deoxyribonucleic acid hybridization and the phenotypic characteristics, three new species, Sphingomonas parapaucimobilis, Sphingomonas yanoikuyae, Sphingomonas adhaesiva, and one new combination, Sphingomonas capsulata, are described. S. parapaucimobilis JCM 7510 (= GIFU 11387), S. yanoikuyae JCM 7371 (= GIFU 9882), and S. adhaesiva JCM 7370 (= GIFU 11458) are designated as the type strains of the three new species. Emended description of the type strain of S. capsulata is presented.

Ten samples of antiserum against Pseudomonas cepacia were prepared by the intravenous immunization of rabbits with heat-killed organisms. Ten P. cepacia strains used for immunization were proven unique antigenic strains. Using these antisera, we serogrouped 127 strains of P. cepacia, and 114 strains (89.8%) fell under one of the ten serogroup. The most prevalent serogroup was C (26.8), the second most prevalent being D (18.1%). When we compared our serogroups with the serogroups of Monteil et al. (H. Monteil, C. Richard, and A. Heidt, Med. Mal. Infect. 11:544-547, 1981) and Heidt et al. (A. Heidt, H. Monteil, and C. Richard, J. Clin. Microbiol. 18:738-740, 1983), five out of seven of their serogroups were represented by our antisera.

Ornithine-containing lipids purified by thin-layer chromatography were found to represent 2-15% of the total extractable cellular lipids in two or three strains each of four Pseudomonas species: P. aeruginosa, P. fluorescens, P. stutzeri and P. cepacia. The structures of the ornithine-containing lipids were elucidated by chemical analysis, thin-layer chromatography, gas-liquid chromatography, gas-liquid chromatography/mass spectrometry (electron impact or secondary ion) and infrared absorption spectroscopy. At least six molecular species of ornithine-containing lipids were present in common in all of the preparations of the four Pseudomonas species. The structure which was the most abundantly in P. fluorescens (about 60% of the total amount of the ornithine-containing lipid) was 3-hydroxyhexadecanoic acid amide-linked to ornithine and esterified to hexadecanoic acid. In addition to this structure, 3-hydroxyoctadecenoic acid amide-linked to ornithine and esterified to hexadecanoic acid was a dominant structure in the ornithine-containing lipids of P. aeruginosa, P. stutzeri or P. cepacia. In P. cepacia, another ornithine-containing lipids with a terminal polar fatty acid, 3-hydroxyhexadecanoic acid amide-linked to ornithine and esterified to 2-hydroxynonadecacyclopropanoic acid or 2-hydroxyoctadecenoic acid, was found; its content, which represented 8-11% of the total extractable cellular lipids, was higher than that of the ornithine-containing lipids with a terminal nonpolar fatty acid. These ornithine-containing lipids exhibited hemagglutinating activity. Additionally, it was very interesting that hydroxy fatty acids included in the ornithine-containing lipids were not found in the phospholipids which represented more than 80% of the total extractable cellular lipids.