TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Gene: (III) selectively disconnects the C-S coupling of sulfur containing heterocyclic compound. (III) has at least one gene chosen from desulfurized gene derived from Rhodococcus genus IGTS8 strain, desulfurized gene derived from Rhodococcus genus KA2-5-1 strain, decomposition gene derived from Sphingomonas genus AD109 strain or desulfurized gene derived from Paenibacillus genus A11-1 strain and A11-2 strain.Preferred Recombinant Microorganisms: (II) utilizes nocardioform mold bacteria as a host. (II) belongs to Rhodococcus genus, Mycobacterium genus or Gordonia genus. SPECIFIC GENES - (III) is desulfurization enzyme gene dSZABCD derived from Rhodococcus genus KA2-5-1 strain (claimed).    EXAMPLE - A loopful of MC0203 strain of Rhodococcus erythropolises was inoculated into 2 ml of NK11 culture medium comprising potassium dihydrogen phosphate, dipotassium hydrogen phosphate, ammonium chloride, ammonium sulfate, glucose, anhydrous magnesium chloride, calcium chloride, anhydrous ferric chloride, anhydrous manganese chloride, zinc chloride, cupric chloride, sodium molybdate and sodium tungstate and was cultured at 30 degreesC for 24 hours. 1 ml of the culture solution obtained by the above culturing method was transferred to 100 ml of NK11 culture medium and was cultured at 30 degreesC for 48 hours. The obtained culture solution was centrifuged at 10000 rpm and the precipitate was suspended in 0.2 M phosphoric acid buffer. The turbidity of the microbial cells at 660 nm was 30.5 ml of 4-hexyl dibenzo thiophene or 4, 6-dipropyl dibenzothiophene in n-tetradecane were added to 100 ml Erlenmeyer flask which contains 5 ml of microbial cells and were allowed to react at 37 degreesC. A control was set-up using 1 strain of R. erythropolises KA2-5. The desulfurizing activity of the microbial cells was determined by measuring the amount of alkylated dibenzo thiophene by HPLC. It was found that the time of desulfurization decreased with the increased concentration of the microbial cells. The dibenzo thiophene was desulfurized by 0203 strain of Rhodococcus. No desulfurization activity was noted in the control.