DESULFURIZATION OF DIBENZOTHIOPHENE AND DIESEL OILS BY A NEWLY ISOLATED GORDONA STRAIN, CYKS1

A dibenzothiophene (DBT)-desulfurizing bacterial strain was isolated a nd identified as Gordona strain CYKS1. Strain CYKS1 was found to trans form DBT to 2-hydroxybiphenyl via the 4S pathway and to be able to als o use organic sulfur compounds other than DBT as a sole sulfur source, Its desulfurization activity was susceptible to sulfate repression. A ctive resting cells for desulfurization could be prepared only in the early growth phase. When two types of diesel oils, middle distillate u nit feed (MDUF) and light gas oil (LGO) containing various organic sul fur compounds including DBT, were treated with resting cells of strain CYKS1 for 12 h, the total sulfur content significantly decreased, fro m 0.15% (wt/wt) to 0.06% (wt/wt) for MDUF and from 0.3% (wt/wt) to 0.2 5% (wt/wt) for LGO. The newly isolated strain CYKS1 is considered to h ave good potential for application in the biodesulfurization of fossil fuels.