Polaromonas naphthalenivorans sp. nov., a naphthalene-degrading bacterium from naphthalene-contaminated sediment

Abstract

Strain CJ2T , capable of growth on naphthalene as a sole carbon and energy source, was isolated from coal-tar-contaminated freshwater sediment. The Gram reaction of strain CJ2 T was negative. The cells were non-spore-forming, non-motile cocci (without flagella). The isolate was found to be an aerobic heterotroph capable of utilizing glucose and other simple sugars. Growth was observed between 4 and 25 6C (optimum, 20 6C) and between pH 6?0 and 9?0 (optimum, pH 7?0-7?5). The G+C content of the genomic DNA was 61?5 mol% and the major quinone was ubiquinone-8. The peptidoglycan of strain CJ2T was determined as belonging to type A1-c, meso-diaminopimelic acid. The major fatty acids of strain CJ2 T were 16 : 1v7c (67?0 %), 16 : 0 (19?6 %), 18 : 1v7c (~7?9 %) and 10 : 0 3-OH (~2?5 %). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Mycolic acid and glycolipids could not be detected. Comparative 16S rDNA analysis indicated that strain CJ2 T is related to the family Comamonadaceae and that the nearest phylogenetic relative was Polaromonas vacuolata 34-P T (97?1 % similarity). On the basis of the physiological and molecular properties, the naphthalene-degrading isolate was designated Polaromonas naphthalenivorans sp. nov. The type strain is CJ2 T (=ATCC BAA-779

Polaromonas eurypsychrophila sp. nov., isolated from an ice core

“…Data are from this study except where indicated. Polaromonas (Irgens et al, 1996;Jeon et al, 2004;K€ ampfer et al, 2006;Sizova & Panikov, 2007;Weon et al, 2008;Margesin et al, 2012). As shown in Table 2, the predominant cellular fatty acids of strain B717-2 T were summed feature 3 (C 16 : 1 !7c and/or iso-C 15 : 0 2-OH; 52.7 %), summed feature 8 (C 18 : 1 !7c, C 18 : 1 !6c; 23.1 %) and C 16 : 0 (21.9 %).…”

“…Growth at various temperatures (0-35 C) was tested in R2A broth at increments of 5 C. The pH range (5.0-11.0) for growth was determined in R2A broth at 15 C. The pH values of <6, 6-9 and >9 were obtained by using sodium acetate/acetic acid, Tris/HCl and Na 2 CO 3 buffers, respectively. Growth in the absence of NaCl and in the presence of 1, 2, 3, 4, 5 and 6 % (w/v) NaCl was also investigated in the same medium at 15 C. Differences in the physiological characteristics between strain B717-2 T and the seven reference strains (Irgens et al, 1996;Jeon et al, 2004;K€ ampfer et al, 2006;Sizova & Panikov, 2007;Weon et al, 2008;Margesin et al, 2012) are given in Table 1.…”

“…At the time of writing, this genus comprised seven recognized species: Polaromonas naphthalenivorans (Jeon et al, 2004), Polaromonas aquatica (K€ ampfer et al, 2006), Polaromonas hydrogenivorans (Sizova & Panikov, 2007), Polaromonas jejuensis (Weon et al, 2008), Polaromonas glacialis (Margesin et al, 2012), Polaromonas cryoconiti (Margesin et al, 2012) and the type species, P. vacuolata (Irgens et al, 1996).…”

“…Table 1. Phenotypic characteristics that differentiate strain B717-2 T from closely related members of the genus Polaromonas Strains: 1, B717-2 T ; 2, P. vacuolata 34-P T (Irgens et al, 1996); 3, P. aquatica CCUG 39402 T (K€ ampfer et al, 2006); 4, P. hydrogenivorans DSM 17735 T (Sizova & Panikov, 2007); 5, P. jejuensis JS12-13 T (Weon et al, 2008); 6, P. naphthalenivorans CJ2 T (Jeon et al, 2004); 7, P. glacialis Cr4-12 T (Margesin et al, 2012); 8, P. cryoconiti Cr4-35 T (Margesin et al, 2012). All eight strains were positive for catalase, cytochrome c oxidase and leucine arylamidase activities and the assimilation of Tweens 40 and 80.…”

“…Members of the genus Polaromonas have been isolated from various environmental sources, such as marine water (Irgens et al, 1996), tap water (K€ ampfer et al, 2006), soil (Weon et al, 2008;Sizova & Panikov, 2007), sediment (Jeon et al, 2004) and glacier cryoconite (Margesin et al, 2012). A novel bacterial strain, B717-2 T , was isolated from an ice core at a depth of 38 m. The whole ice core was 120 m in length drilled from Muztagh Glacier (83.7 E 26.4 N) on the Tibetan Plateau, China.…”