Manipulation of the DNA coding for the desulphurizing activity in a new isolate of Arthrobacter sp.

A new bacterial strain able to cleave C-S bonds from organosulphur heterocy clic compounds through the 4-S pathway and tentatively classified as Arthro bacter sp. was recently isolated. In the present short article we describe the cloning and the characterization of the DNA encoding the enzymes respon sible for desulphurization in this microorganism, referred to as Arthrobact er sp. DS7. The desulphurization operon was found to be located in a large plasmid that also bears the genes conferring cadmium and arsenic resistance . By shortening this plasmid, a new cloning vector was prepared and used to obtain a recombinant derivative strain that desulphurizes dibenzothiophene despite of the presence of inorganic sulphur in the growth medium.