Numerical Taxonomy of Pseudomonas alcaligenes, P. pseudoalcaligenes, P. mendocina, P. stutzeri, and Related Bacteria

Abstract

A numerical phenotypic analysis, in which the unweighted pair group average linkage method and Dice similarity coefficient were used, was performed on 155 strains received as Pseudomonas alcaligenes, Pseudomonas pseudoalcaligenes, Pseudomonas mendocina, or Pseudomonas stutzeri. These organisms are the clinically important nonfluorescent species belonging to ribosomal ribonucleic acid group I of Palleroni and co-workers. Six major clusters, which could be further divided into 20 subclusters, were formed. Most strains received as P. alcaligenes fell into three subclusters (subclusters Al, A2, and Bl), whereas strains received as P. pseudoalcaligenes were mainly classified in two other subclusters (subclusters C2 and C3). All but two strains (subcluster D1) of organisms received as P. mendocina were grouped in subcluster D2. Most of the 45 strains received as P. stutzeri were contained in a large subcluster, subcluster E2 (39 strains). Strains belonging to fluorescent pseudomonad species (Pseudomonas aeruginosa, Pseudomonas jluorescens, and Pseudomonas putida), which were included in the analysis for control purposes, were contained in one cluster, which comprised seven subclusters.During recent years, Pseudomonas spp. strains have been studied with increasing interest because of their importance in medical and food microbiology and in phytopathology .Since the classical study of Stanier et al. (30) on Pseudomonas taxonomy, most of the analyses performed on these strains have pointed to the genomic heterogeneity of the genus (5, 17, 35). However, very few studies have been carried out at the species level to revise the phenotypic definitions of these organisms and to determine their genomic positions by deoxyribonucleic acid (DNA)-DNA hybridization. Only fluorescent Pseudomonas spp. strains and strains isolated from meat have been the subjects of several taxonomic studies at the species level (2, 3, 14-16, 24, 26, 34). Although the nutritional characteristics given by Stanier et al. (30) are still potentially the most useful for differentiation, the lack of other phenotypic data leads to difficulties in developing identification schemes.The aim of this study was to define, by using a numerical phenotypic analysis, species known to belong to ribosomal ribonucleic acid group I (18) on the basis of DNA-ribosomal ribonucleic acid hybridization (17), particularly the clinically important species of this group, which were received as Pseudomonas alcaligenes, Pseudomonas pseudoalcaligenes, Pseudomonas mendocina, or Pseudomonas stutzeri. Later, we intend to study the phenotypic groups by using DNA-DNA hybridization. MATERIALS AND METHODSBacterial strains. A total of 155 strains were included in the analysis. These organisms comprised type and other reference strains received from diverse culture collections as P. alcaligenes, P. pseudoalcaligenes, P. mendocina, or P. stutzeri. Strains belonging to Pseudomonas f luorescens biovars A, B, C, F, and G, Pseudomonas chlororaphis, Pseu-* Corresponding author. domonas aureofacie...

A prominent role for glucosylglycerol in the adaptation of Pseudomonas mendocina SKB70 to osmotic stress

“…These data most likely indicate that the concentrations of organic os- Table 3), indicating that they all osmoregulate in a similar manner. In contrast, P. stutzeri JM300, a more distantly related (14,30), salt-sensitive species did not accumulate any of these three osmolytes at high osmolarity (data not shown).…”

“…Thus, these results confirm that strain SKB70 is a Pseudomonas species (30). However, in contrast to the fatty acid analysis, the nutritional analysis strongly suggests that the species is more likely P. mendocina rather than the closely related species P. pseudoalcaligenes (14,30,32). Additional characteristics confirming this assignment were the yellow cellular pigmentation of the strain, a distinctive feature of P. mendocina (32), and its ability to grow at the expense of geraniol, a property that is strictly restricted to the species P. aeruginosa and P. mendocina (30).…”

Biology of Pseudomonas stutzeri

“…Phenotypic identification based on the characteristics given in the species definition and following dichotomous keys is usually satisfactory (26,115). At present, studies of nutritional properties are frequently carried out with commercial kits designed to reduce the labor involved in traditional methods.…”

Pseudomonas mosselii sp. nov., a novel species isolated from clinical specimens.

“…rieux), incubated at 30 mC for 4 h. They were scored according to the manufacturer's recommendations. Tests which were either positive or negative for all the strains were not included in the numerical analysis ; other data were coded 1 for positive results, 0 for negative results and subjected to numerical analysis as described by Gavini et al (1989). c), where ' a ' is the number of positive resemblances, and ' b ' and ' c ' are the number of divergences.…”

“…Forty-four conventional tests were performed as described by Gavini et al (1989). Assimilation of 147 compounds, including carbohydrates, organic acids and amino acids, as sole carbon source was tested using API 50-CH, API 50-AO and API 50-AA galleries (bioMe!…”