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Thirty-five bacterial strains capable of converting dibenzothiophene into 2-hydroxybiphenyl were isolated. Among them Rhodococcus erythropolis KA2-5-1 was chosen for further characterization because of its ability to retain high desulfurization activity stably. PCR cloning and DNA sequencing of a KA2-5-1 genomic DNA fragment showed that it was practically(More)
The thermophilic bacterium Paenibacillus sp. A11-2, which can utilize dibenzothiophene (DBT) as the sole sulfur source at high temperature (45-55 degrees C), was investigated for its ability to cleave carbon-sulfur bonds in the dibenzothiophene (DBT) ring with asymmetrical alkyl substitution, such as methyl, dimethyl, trimethyl, ethyl and propyl DBTs. The(More)
A benzothiophene (BT) and dibenzothiophene (DBT) monooxygenase (TdsC), which catalyzes the oxidation of the sulfur atoms in BT and DBT molecules, was purified from Paenibacillus sp. strain A11-2. The molecular mass of the purified enzyme and its subunit were determined to be 200 kDa and 43 kDa by gel filtration and sodium dodecyl sulfate polyacrylamide gel(More)
The Rhodococcus erythropolis strain KA2-5-1 was characterized by its ability to cleave carbon-sulfur bonds in the dibenzothiophene (DBT) ring by asymmetrically alkyl substitution, such as C2-DBTs (e.g., dimethyl and ethyl DBTs) and C3-DBTs (e.g., trimethyl and propyl DBTs), which are known to remain in hydrodesulfurization-treated diesel fuels. After(More)
Petroleum contains many heterocyclic organosulfur compounds refractory to conventional hydrodesulfurization carried out with chemical catalysts. Among these, dibenzothiophene (DBT) and DBTs bearing alkyl substitutions are representative compounds. Two bacterial strains, which have been identified as Paenibacillus strains and which are capable of efficiently(More)
Paenibacillus sp. strain A11-2, which had been primarily isolated as a bacterial strain capable of desulfurizing dibenzothiophene to produce 2-hydroxybiphenyl at high temperatures, was found to desulfurize benzothiophene more efficiently than dibenzothiophene. The desulfurized product was identified as o-hydroxystyrene by GC-MS and 1H-NMR analysis.(More)
Paenibacillus A11-2 can efficiently cleave two carbon&bond;sulfur bonds in dibenzothiophene (DBT) and alkyl DBTs, which are refractory by conventional petroleum hydrodesulfurization, to remove sulfur atom at high temperatures. An 8.7-kb DNA fragment containing the genes for the DBT desulfurizing enzymes of A11-2 was cloned in Escherichia coli and(More)
A benzothiophene desulfurizing bacterium was isolated and identified as Rhodococcus sp. strain T09. Growth assays revealed that this strain assimilated, as the sole sulfur source, various organosulfur compounds that cannot be assimilated by the well-studied dibenzothiophene-desulfurizing Rhodococcus sp. IGTS8. The cellular growth rate of strain T09 for the(More)
Porcine and bovine brain high Ca2+-requiring neutral proteases were purified to homogeneity by the same isolation procedures, and their properties were compared. A high degree of similarity existed between the two proteases. The purification procedures included ion-exchange chromatography on DEAE-cellulose, hydrophobic chromatography on phenyl-Sepharose(More)