Cloning Of DszB Involved In Specific Desulfurization Of Dibenzothiophene, Identification And Optimization Of Fermentation Process By A Newly Isolated Gordona Nitida,LSSEJ-1,

42 strains were isolated from polluting soils of Dagang oil-field and Shengli oil-field by using dibenzothiophene(DBT)-selective enrichment culture techniques. All of the microorganisms were able to degrade dibenzothiophene (DBT),but not via the 4S pathway except only one strain LSSEJ-1.Strain LSSEJ-1 was found to be able to use DBT as a sole sulfur source and to transform DBT to 2-hydroxybiphenyl via the 4S pathway. Comparison of the 16S rDNA of strain LSSEJ-1 with that of Genbank indicated that LSSEJ-1 have high homology with Gordona strain in phylogenetic framework of bacterial classification. The dszB gene Involved in Specific Desulfurization of Dibenzothiophene was cloned by PCR. The fermentation medium optimized by means of the shaking cultures contained per liter of deionized water, KH2PO4 2.44g, Na2HPO4.12H2O 12.03g, MgCl2.6H2O 0.4g, NH4NO3 2g, MnCl2.4H2O 4mg, FeCl3.6H2O Img, CaCl2 0.75mg, DBT 20mg, glucose 3g.The optimum fermentation conditions were the temperature 30,initial pH value 8-9 in the culture, the cultures were performed in 500ml flasks with 100ml of MSM,1% of inoculated volume,3 days of the liquid culture age.