A bacterium designated strain BD-a59, able to degrade all six benzene, toluene, ethylbenzene, and o-, m-, and p-xylene (BTEX) compounds, was isolated by plating gasoline-contaminated sediment from a gasoline station in Geoje, Republic of Korea, without enrichment, on minimal salts basal (MSB) agar containing 0.01% yeast extract, with BTEX as the sole carbon and energy source. Taxonomic analyses showed that the isolate belonged to Pseudoxanthomonas spadix, and until now, the genus Pseudoxanthomonas has not included any known BTEX degraders. The BTEX biodegradation rate was very low in MSB broth, but adding a small amount of yeast extract greatly enhanced the biodegradation. Interestingly, degradation occurred very quickly in slurry systems amended with sterile soil solids but not with aqueous soil extract. Moreover, if soil was combusted first to remove organic matter, the enhancement effect on BTEX biodegradation was lost, indicating that some components of insoluble organic compounds are nutritionally beneficial for BTEX degradation. Reverse transcriptase PCR-based analysis of field-fixed mRNA revealed expression of the tmoA gene, whose sequence was closely related to that carried by strain BD-a59. This study suggests that strain BD-a59 has the potential to assist in BTEX biodegradation at contaminated sites.

A Gram-negative, strictly aerobic, non-spore-forming bacterium, designated strain BD-c194 T , was isolated from diesel-contaminated soil in Geoje, Korea. The cells were short, motile rods with single polar flagella. Growth of strain BD-c194 T was observed between 15 and 45 6C (optimally at 30-35 6C) and between pH 6.0 and 9.5 (optimally at pH 7.5-9.0). The predominant fatty acids were 11-methyl C 18 : 1 v7c, C 16 : 0 , C 18 : 1 v7c, C 18 : 0 and an unknown fatty acid (equivalent chain-length 18.814); a large amount of phosphatidylglycerol and a small amount of diphosphatidylglycerol were present as polar lipids. The G+C content of the genomic DNA was 60.8 mol% and the major isoprenoid quinone was Q-10. A comparative 16S rRNA gene sequence analysis showed that strain BD-c194 T formed a well-defined phyletic lineage within the genus Devosia (with 100 % bootstrap support). The levels of 16S rRNA gene sequence similarity with respect to the type strains of other Devosia species ranged from 95.0 to 96.1 %. On the basis of chemotaxonomic data and molecular properties, strain BD-c194 T represents a novel species within the genus Devosia, for which the name Devosia geojensis sp. nov. is proposed. The type strain is BD-c194 T (5KCTC 22082 T 5DSM 19414 T). The genus Devosia (family Hyphomicrobiaceae, order Rhizobiales, class Alphaproteobacteria) was first described by Nakagawa et al. (1996) with the transfer of 'Pseudomonas riboflavina' (Foster, 1944) to Devosia riboflavina. At the time of writing, the genus comprises six species: Devosia riboflavina (Nakagawa et al., 1996), D. neptuniae (Rivas et al., 2003), D. limi (Vanparys et al., 2005), D. soli (Yoo et al., 2006), D. insulae (Yoon et al., 2007) and D. subaequoris (Lee, 2007). In the course of the screening of microorganisms from contaminated soil, we isolated a novel bacterium, designated strain BD-c194 T , belonging to the genus Devosia. Here we describe the polyphasic analysis used to determine its taxonomic position. Diesel-contaminated soil was collected from the diesel-contaminated soil surface of a gas (petrol) station on Geoje Island, Korea. The total petroleum hydrocarbon content of the contaminated soil was about 2000 mg kg 21. The soil sample was serially diluted with a 1 % (w/v) saline solution and spread on R2A agar (Difco). After 5 days incubation at 25 u C, strain BD-c194 T was selected from an agar plate and analysed. Although strain BD-c194 T was isolated from diesel-contaminated soil, it did not grow on minimal agar medium (Stanier et al., 1966) containing diesel as the sole carbon and energy source, showing that the strain is not a diesel degrader. The morphological, physiological and biochemical characteristics of strain BD-c194 T were examined using routine cultivation on R2A medium at 30 u C for 3 days (except where indicated otherwise). The type strains of some related taxa (see Table 1) were used as reference strains for the biochemical tests. The temperatures and pH for growth of strain BD-c194 T were investigated by growing the isolate on R2A...

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Removal of phenol by wet air oxidation was conducted with 1 wt% Pt/Al2O3 catalyst in a batch reactor and in a continuous flow fluidized bed reactor with air lift tube operated at 423 K and 1.4 MPa. After 60 min in the batch reactor with initial phenol concentration of 1000 mg/l, almost complete conversion into CO2 and H2O was achieved. Pt/Al2O3 catalyst deactivation was observed during the wet oxidation reaction. TEM, EDX, XPS and TPO analyses showed the deactivation was caused by formation and deposition of carbonaceous materials on the catalyst surface. TEM of the deactivated Pt/Al2O3 showed formation of filamentous materials, which linked Pt particles, and some Pt particles were completely encapsulated by deposited material. XPS analysis showed that the carbonaceous materials on the catalyst consisted of four different morphologies (C1, C2, C3, C4). As the wet oxidation proceeded, the C1 peak increased gradually with reaction time, whereas the C2 and C3 peaks passed through maxima. At around the C2 and C3 peak maxima, the C4 peak began to appear and increased continuously up to 10 h reaction. This result indicates that at least two carbonaceous materials of C2 and C3 were transformed morphologically into C4 material. The broad profiles of CO2 formation from the TPO experiment implied that at least two types of carbon deposits were oxidized at different temperatures, one type on Pt particles, the other type on Al2O3. The carbonaceous deposit was formed on Pt particles and migrated continuously onto the support. The continuous flow fluidized bed reactor showed very stable wet oxidation performances in the presence of the air lift tube. The air lift tube was important in continuously regenerating the deactivated catalyst. The accumulated carbon deposits were reduced drastically by the action of the air lift tube.