Isolation and characterization of an s-ethyl-N,N-dipropylthiocarbamate-degrading Arthrobacter strain and evidence for plasmid-associated s-ethyl-N,N-dipropylthiocarbamate degradation.

Arthrobacter sp. strain TE1 isolated from s-ethyl-N,N-dipropylthiocarbamate (EPTC)-exposed soil degraded this herbicide effectively and could grow on EPTC as the sole carbon source. TE1 harboured four plasmids of 65.5, 60, 50.5, and 2.5 megadaltons. Spontaneous mutants unable to degrade EPTC arose at a high frequency, and this was further increased by treatment of the culture with acridine orange or incubation at high temperature. All EPTC degradation-deficient (E-) mutants lacked the 50.5-megadalton plasmid. This plasmid could be transferred from TE1 to E- mutants by conjugation, resulting in the restoration of EPTC-degrading ability to the mutants.