DESULFURIZATION OF ALKYL AND AROMATIC SULFIDES AND SULFONATES BY DIBENZOTHIOPHENE-DESULFURIZING RHODOCOCCUS SP STRAIN SY1

A dibenzothiophene (DBT)-desulfurizing bacterium, Rhodococcus sp, strain SY1 could also use dimethyl sulfide (DMS), dimethyl sulfoxide (DMSO), and several alkylsulfonates as sole sources of sulfur. Strain SY1 grown on DMSO accumulated DMS, dimethyl sulfone (DMSO(2)), and methanol in the culture medium and methane in the gas phase, and methane was the product of methanesulfonate desulfonation, These results indicated that strain SY1 could finally degrade DMS in the oxidative pathway via DMSO, DMSO(2), and methanesulfonate to methane and sulfate, reducing a part of DMSO back to DMS, From desulfonation patterns of alkyl and aromatic sulfonates, different types of desulfonation are proposed, Sulfate was suggested to repress the expression of the enzymes involved in DBT desulfurization. Removal of the sulfate produced by the addition of BaCl2 enhanced the degradation rate of DBT about 14%.