This report describes phenanthrene uptake as well as the effect of phenanthrene on the membrane phospholipid and fatty acid composition in a newly isolated bacterial strain, Sphe3, that we taxonomically identified as Arthrobacter sp. Strain Sphe3 is able to utilize phenanthrene as a carbon source at high rates and appears to internalize phenanthrene with two mechanisms: a passive diffusion when cells are grown on glucose, and an inducible active transport system when cells are grown on phenanthrene as a sole carbon source. Active transport followed Michaelis-Menten kinetics, and it was amenable to inhibition by 2,4-dinitrophenol and sodium azide. Evidence provided here indicates that apart from inducing an active PAH uptake, the presence of phenanthrene elicits significant changes in membrane fluidity.

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A novel phenanthrene-degrading bacterium, designated strain Sphe3 T , was isolated from a creosote-contaminated soil in Greece. Cells were non-motile, Gram-positive, aerobic, and rod-to coccus-shaped. The strain was isolated on the basis of formation of a clear zone on agar plates sprayed with phenanthrene. Optimal growth occurred at 30 6C. The G+C content of the DNA was 65.7 mol%. The polar lipid pattern of strain Sphe3 T consisted of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The dominant fatty acids were iso-C 15 : 0 , anteiso-C 15 : 0 , iso-C 16 : 0 , C 16 : 0 and anteiso-C 17 : 0 , representing .86 % of the total fatty acids. The predominant isoprenoid quinone of strain Sphe3 T was menaquinone-8 (MK-8). Based on 16S rRNA gene sequence analysis, strain Sphe3 T showed 99 and 98.9 % similarity to the type strains of Arthrobacter oxydans and Arthrobacter polychromogenes, respectively. Strain Sphe3 T showed 91 % similarity to homologues of A. oxydans and A. polychromogenes based on recA gene sequence analysis. Based on 16S rRNA and recA gene sequence analysis and DNA-DNA hybridization analysis, as well as physiological and chemotaxonomic characteristics, it is concluded that strain Sphe3 T represents a novel species of the genus Arthrobacter, for which the name Arthrobacter phenanthrenivorans sp. nov. is proposed. The type strain is Sphe3 T (5DSM 18606 T 5LMG 23796 T ).Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that are found in many polluted soils as a result of natural or industrial activities, including those of creosote wood-treatment facilities (Mueller et al., 1989). PAHs have attracted considerable attention because of their potential toxicity for higher organisms and resistance to microbial degradation (Kanaly & Harayama, 2000). A wide range of micro-organisms have been discovered that are able to degrade highly stable, toxic organic compounds such as polycyclic and aliphatic hydrocarbons (Habe & Omori, 2003;Kanaly & Harayama, 2000;Van Hamme et al., 2003). Among these micro-organisms, several Arthrobacter species are able to degrade PAHs (Grifoll et al., 1992;Seo et al., 2006). We have previously reported the phenanthrene uptake activity and membrane lipid alterations of a PAH-degrading Arthrobacter strain, Sphe3, isolated from a creosote-contaminated soil in Greece (Kallimanis et al., 2007). In the present study, on the basis of phylogenetic analysis of 16S rRNA and recA gene sequences, together with physiological and chemotaxonomic characteristics and DNA-DNA hybridization analysis, we demonstrate that strain Sphe3 represents a novel species of the genus Arthrobacter.Strain Sphe3 T was isolated from Perivleptos, a creosotepolluted site in Epirus, Greece (12 km north of the city of Ioannina), in which a wood-preserving industry had operated for over 30 years (Kallimanis et al., 2007). Soil samples (10 g) were mixed with 100 ml of minimal medium M9 (Sambrook et al., 1989) supplemented with 0.01 % (w/v) phenanthrene (in crystal form) as the sole ca...

Three bacterial strains, designated as Wphe1, Sphe1, and Ophe1, were isolated from Greek soils contaminated with polycyclic aromatic hydrocarbon (PAH)-containing waste from the wood processing, steel, and oil refinery industries. Wphe1, Sphe1, and Ophe1 were characterized and identified as species of Pseudomonas, Microbacterium, and Paracoccus, respectively, based on Gram staining, biochemical tests, phospholipid analysis, FAME analysis, G+C content and 16S rRNA gene sequence analysis. The results of gas chromatography showed that strain Wphe1 degraded naphthalene, phenanthrene, and m-cresol over a wide temperature range; strain Sphe1 was a degrader of phenanthrene and n-alkanes; most interestingly, strain Ophe1 degraded anthracene, phenanthrene, fluorene, fluoranthene, chrysene, and pyrene, as well as cresol compounds and n-alkanes as sole carbon source. This is the first report of a representative of the genus Paracoccus capable of degrading PAHs with such versatility. These three strains may be useful for bioremediation applications.

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