Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Sat, 09 Mar 2019 02:06:59 International Journal of Systematic and Evolutionary Microbiology (2002), 52, 2113–2120 DOI : 10.1099/ijs.0.02197-0 NOTE Pseudomonas extremorientalis sp. nov., isolated from a drinking water reservoir 1 Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, 690022 Vladivostok, Pr. 100 Let Vladivostoku 159, Russia 2 Industrial Research Institute Swinburne, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia 3 Laboratory of Microbiology, Graduate School of Fisheries Sciences, Faculty of Fisheries, Hokkaido University, 3-1-1 Minato- cho, Hakodate 041-8611, Japan 4 Institute of Microbiology of the Russian Academy of Sciences, 117811 Moscow, Russia 5 Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences, 690041, Vladivostok, Russia 6 UMR 6078 CNRS & Universite  de Nice Sophia Antipolis, Laboratoire Jean Maetz, Villefranche-sur- Mer F06230, France Elena P. Ivanova, 1,2 † Nataliya M. Gorshkova, 1 Tomoo Sawabe, 3 Karin Hayashi, 3 Nataliya I. Kalinovskaya, 1 Anatolii M. Lysenko, 4 Natalie V. Zhukova, 5 Dan V. Nicolau, 2 Tatyana A. Kuznetsova, 1 Valery V. Mikhailov 1 and Richard Christen 6 Author for correspondence : Elena P. Ivanova. Tel : 61 3 9214 5137. Fax: 61 3 9214 5050. e-mail : eivanovaswin.edu.au On the basis of phenotypic and genotypic characteristics and 16S rDNA sequence analysis, a novel species belonging to the genus Pseudomonas sensu stricto was identified. The saprophytic, fluorescent bacterium, designated KMM 3447 T , was isolated from a drinking water reservoir near Vladivostok City, Russia. The novel organism was a Gram-negative, aerobic, rod-shaped bacterium that produced a cyclic depsipeptide with surface-active properties. It degraded casein, but did not degrade gelatin, starch, agar or Tween 80. The bacterium was also haemolytic. Growth of the novel bacterium occurred between 4 and 35 C. The predominant cellular fatty acids of the novel pseudomonad were C 16:0 ,C 16:1(n-7) ,C 18:1(n-7) and C 17:0 cyclo ; branched fatty acids were only found in trace amounts. The GMC content of the novel bacterium was 610 mol %. 16S rDNA sequence analysis indicated that the novel bacterium had a clear affiliation with Pseudomonas fluorescens and species closely related to this recognized pseudomonad. DNA–DNA hybridization experiments showed that the novel bacterium bound at low levels (27–53 %) with the DNA of the type strains of its nearest phylogenetic relatives, namely Pseudomonas tolaasii, Pseudomonas veronii, Pseudomonas orientalis and Pseudomonas rhodesiae, indicating that the novel bacterium represented a novel species within the genus Pseudomonas, for which the name Pseudomonas extremorientalis is proposed; the type strain is KMM 3447 T ( LMG 19695 T ). Keywords : Proteobacteria, Pseudomonas sensu stricto, Pseudomonas extremorientalis The genus Pseudomonas as described by Migula (1894) consisted of a diverse group of bacteria that were common inhabitants of soil and fresh water eco- systems. During the last decade, bacteria belonging to the genus Pseudomonas have been studied extensively using polyphasic approaches, and these studies have led to the improved classification of members of this genus (see reviews by De Ley, 1992 ; Kersters et al., 1996 ; Moore et al., 1996). Currently, the genus Pseudomonas sensu stricto consists of two major ................................................................................................................................................. † Present address : Industrial Research Institute Swinburne, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia. The GenBank accession number for the 16S rRNA gene sequence of Pseudomonas extremorientalis KMM 3447 T is AF405328. The full phylogenetic tree from which Fig. 1 was taken can be found as supplementary data in IJSEM Online (http ://ijs.sgmjournals.org). intrageneric clusters – one focussed around Pseudo- monas aeruginosa and one focussed around Pseudo- monas fluorescens (Moore et al., 1996). In the last decade, the number of species belonging to the latter cluster has grown due to the characterization of a number of strains isolated from natural mineral waters (Coroler et al., 1996 ; Elomari et al., 1996 ; Verhille et al., 1999 ; Dabboussi et al., 1999). During the taxonomic investigation of bacterial popu- lations of a drinking water reservoir in the Far East of Russia, we isolated a number of strains that belonged to different genera, including Aeromonas, Vibrio (Ivanova et al., 2001) and Pseudomonas. The aim of this study was to characterize one of the strains isolated from the reservoir, designated KMM 3447 T , which had phenotypic, chemotaxonomic, genetic and phylo- genetic characteristics distinct from other recognized 02197  2002 IUMS Printed in Great Britain 2113