A soil bacterium, designated strain KK22, was isolated from a phenanthrene enrichment culture of a bacterial consortium that grew on diesel fuel, and it was found to biotransform the persistent environmental pollutant and high-molecular-weight polycyclic aromatic hydrocarbon (PAH) benz[a]anthracene. Nearly complete sequencing of the 16S rRNA gene of strain KK22 and phylogenetic analysis revealed that this organism is a new member of the genus Sphingobium. An 8-day time course study that consisted of whole-culture extractions followed by high-performance liquid chromatography (HPLC) analyses with fluorescence detection showed that 80 to 90% biodegradation of 2.5 mg liter H igh-molecular-weight polycyclic aromatic hydrocarbons (HMW PAHs) are commonly occurring environmental pollutants that are generally considered to be more resistant to biodegradation than their lower-molecular-weight aromatic counterparts (1-4). Many are suspected carcinogens and display genotoxic and immunotoxic properties in addition to causing oxidative cell damage (5, 6). The HMW PAH benz [a]anthracene is considered to be environmentally recalcitrant, is classified as a group 2A carcinogen by the International Agency for Research on Cancer, and is included in the U.S. Environmental Protection Agency's Priority Pollutant List. As such, there is much interest in understanding the environmental fate of benz[a]anthracene and the mechanisms by which it may be transformed.Few studies have documented the bacterial biotransformation of benz [a]anthracene even though many studies have documented the biotransformation of the structurally similar threering angular kata-annelated PAH phenanthrene (7-16) and, although less so, also the structurally similar three-ring linear kata-annelated PAH anthracene (7,13,(17)(18)(19). The benz [a]anthracene molecule itself is comprised of four aromatic rings that are bonded via both linear and angular kata annelation, and it may be thought of as a benzannelated derivative of either phenanthrene or anthracene. Initial enzymatic oxidation of the aromatic ring system of benz [a]anthracene may occur at various locations on the molecule, including via the 1,2-or 3,4-carbon positions, an angular kata-type initial dioxygenation, via the 8,9-or 10,11-carbon positions, a linear kata-type initial dioxygenation, or via the K-region at the 5,6-carbon positions. If metabolites that represent the initial oxidation steps are not directly recovered in metabolism studies, identification of downstream metabolites may allow for predicting whether an angular kata-, linear kata-, or K region-type initial dioxygenation originally occurred. For example, 2-hydroxy-3-naphthoic acid may occur as a downstream metabolite of benz [a]anthracene biotransformation through an angular katatype initial dioxygenation event.To date, metabolites from the biotransformation of benz[a]anthracene by bacteria have been identified from only four organisms. In chronological order, they are (i) Sphingobium yanoikuyae mutant strain B8/36 (20-22), (ii) S. yanoiku...

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A Gram-stain-negative, yellow, rod-shaped bacterium, designated strain KK22T , was isolated from a microbial consortium that grew on diesel fuel originally recovered from cattle pasture soil. Strain KK22 T has been studied for its ability to biotransform high molecular weight polycyclic aromatic hydrocarbons. On the basis of 16S rRNA gene sequence phylogeny, strain KK22T was affiliated with the genus Sphingobium in the phylum Proteobacteria and was most closely related to Sphingobium fuliginis TKP T (99.8 %) and less closely related to Sphingobium quisquiliarum P25 T (97.5 %). Results of DNA-DNA hybridization (DDH) revealed relatedness values between strain KK22 T and strain TKP T and between strain KK22 T and strain P25 T of 21¡4 % (reciprocal hybridization, 27¡2 %) and 15¡2 % (reciprocal hybridization, 17¡1 %), respectively. Chemotaxonomic analyses of strain KK22 T showed that the major respiratory quinone was ubiquinone Q-10, that the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidyl-N-methylethylethanolamine and sphingoglycolipid, and that C 18 : 1 v7c and C 14 : 0 2-OH were the main fatty acid and hydroxylated fatty acids, respectively. This strain was unable to reduce nitrate and the genomic DNA G+C content was 64.7 mol%. Based upon the results of the DDH analyses, the fact that strain KK22 T was motile, and its biochemical and physiological characteristics, strain KK22 T could be separated from recognized species of the genus Sphingobium. We conclude that strain KK22 T represents a novel species of this genus for which the name Sphingobium barthaii sp. nov. is proposed; the type strain is KK22 T (5DSM 29313 T 5JCM 30309 T ).

In September 1988, a Hitachi-GE model PG5341 gas turbine installed at the Tokuyama refinery of Idemitsu Kosan Co., Ltd. (Japan) successfully recorded 100,325 hours of base load operation over a period of 13 years with 99.4% reliability. The generated power totalled 1,341,770 MWh at the time of final shutdown. The gas turbine, burning Bunker A oil, LPG, and heavy distillate oil, had been the main equipment in a cogeneration plant with a simple heat recovery steam generator using waste heat from the exhaust gas, plus a refired boiler. It was expected that several costly hot gas path components of this turbine would have to be replaced in the near future, and it was not as fuel efficient as more modern designs, so it was decided to replace the PG5341 with a Hitachi H-25 gas turbine. This new model H-25 is designed to have a rated output of 26,200kW and an efficiency of 32.3% (LHV) at the generator terminals under ISO conditions. By the use of a pressure ratio of 14.7 (up from 10.1) and a combustor outlet gas temperature of 1,260°C (up from 980°C), it is expected that efficiency of gas turbine will be improved relatively by 18.7% on a design basis, compared with the PG5341. A factory full-load test of the prototype H-25 gas turbine was completed in August 1988 with excellent results. This machine has been in place and in operation at the Tokuyama plant since the end of November 1988. This is the first commercial application of the Hitachi H-25 advanced gas turbine.