System. App!. Microbio!. 19, 510-527 (1996) © Gustav Fischer Verlag Ability of Biolog and Biotype-100 Systems to Reveal the Taxonomic Diversity of the Pseudomonads PATRICK A. D. GRIMONT!, MARC VANCANNEYT2, MARTINE LEFEVRE!, KATRIEN VANDEMEULEBROECKE 2 , LUC VAUTERIN 2 , ROLAND BROSCH!, KAREL KERSTERS 2 , and FRANCINE GRIMONT 1 1 Unite des Enterobacteries, Unite INSERM 389, Institut Pasteur, F-75724 Paris Cedex 15, France 2 Laboratorium voor Microbiologie, Universiteit Gent, Ledeganckstraat 35, B-9000 Gent, Belgium Received June 13, 1996 Summary A total of 224 strains of the genus Pseudomonas sensu lato were studied by 99 carbon source utilization tests using BioMerieux Biotype-100 strips and 96 substrate oxidation tests using the Biolog GN Micro Plate system. Biotype-100 and Biolog data were computer analyzed using programs of the Taxotron pack- age (Institut Pasteur) and the Bionum software (Biolog), respectively. Unweighted pair group method of averages (UPGMA) yielded 34 Biotype phenons and 36 Biolog phenons. A total of 18 phenons had iden- tical composition in both systems. Six phenons were almost identical in structure whereas some phenons in one system were lumped in the other system. Some species (represented by at least three strains) con- stituted homogeneous phenons in both Biotype-1 00 and Biolog systems: Pseudomonas aeruginosa, P. to- laasii, P. mendocina, P. cichorii, P. viridif/ava, P. (ragi, P. stutzeri, P. agarici, P. alcaligenes, and P. pseudoal- caligenes. None of the two systems could discriminate P. (uscovaginae from P. asplenii, and P. caricapa- payae from P. corona(aciens. P. corrugata was a tight subphenon in both systems. Strains labeled P. f/uo- rescens were found in six phenons with either Biotype-100 or Biolog systems. Strains of P. putida were found in three (Biolog) or four (Biotype) phenons. Strains of P. marginalis were distributed over five phen- ons in both systems. The use of Biotype-lOO strips for Pseudomonas characterization was also validated by comparison with published carbon source utilization data. Key words: Pseudomonas - Biochemical tests - Environment Introduction The taxonomy of aerobic gram-negative bacteria of the genus Pseudomonas sensu lato has considerably benefited from the nutritional studies of Stanier et ai. (1966), which showed that the ability of Pseudomonas strains to utilize different compounds as sole source of carbon and energy can be used as a general method for their phenotypic char- acterization. Later, DNA-DNA (Palleroni et aI., 1972), and rRNA- DNA (Palleroni et aI., 1973, De Vos and De Ley, 1983) hybridization and 165 rRNA sequencing (Fox et aI., 1980) provided overwhelming evidence for splitting the genus Pseudomonas sensu lato into five separate groups. A con- cise overview of the current knowledge of the phylogenet- ic relationships, classification and nomenclature of all cur- rently and validly described species of the genus Pseudo- monas is given by Kersters et ai. (1966). RNA group I con- tains the genus Pseudomonas sensu stricto. RNA group II contains the genera Burkholderia and Ralstonia (Yabu- uchi et aI., 1992, 1995). RNA group III corresponds to the Comamonadaceae with the genera Comamonas, Acidov- orax, and Hydrogenophaga (De Vos et aI., 1985, Tamao- ka et aI., 1987, Willems et aI., 1989, 1990, 1991), which all contain previously named Pseudomonas species. RNA group IV contains the genus Brevundimonas (Segers et aI., 1994). RNA group V (P. maltophilia) has been transferred to the genus Xanthomonas (Swings et aI., 1983) and sub- sequently to a new genus Stenotrophomonas (Palleroni and Bradbury, 1993). Most recent taxonomic changes were supported by nu- cleic acid hybridization or rRNA sequencing, whole-cell