CLONING OF THE GENES FOR DEGRADATION OF THE HERBICIDES EPTC (S-ETHYL DIPROPYLTHIOCARBAMATE) AND ATRAZINE FROM RHODOCOCCUS SP STRAIN TE1

The degradation of the herbicides EPTC (S-ethyl dipropylthiocarbamate) and atrazine loro-4-ethylamino-6-isopropylamine-1,3,5-triazine) is as sociated with an indigenous plasmid in Rhodococcus sp. strain TE1. Pla smid DNA libraries of Rhodococcus sp. strain TE1 were constructed in a Rhodococcus-Escherichia coli shuttle vector, pBS305, and transferred into Rhodococcus sp. strain TE3, a derivative of Rhodococcus sp. strai n TE1 lacking herbicide degradation activity, to select transformants capable of growing on EPTC as the sole source of carbon (EPTC(+)). Ana lysis of plasmids from the EPTC(+) transformants indicated that the ep tA gene, which codes for the enzyme required for EPTC degradation, res ides on a 6.2-kb KpnI fragment. The cloned fragment also harbored the gene required for atrazine N dealkylation (atrA). The plasmid carrying the cloned fragment could be electroporated into a number of other Rh odococcus strains in which both eptA and atrA were fully expressed. No expression of the cloned genes was evident in E. coli strains. Subclo ning of the 6.2-kb fragment to distinguish between EPTC- and atrazine- degrading genes was not successful.