CHARACTERISATION A PART OF GENE ENCODED DIOXYGENASE OF DIBENZOFURAN DEGRADADING STRAIN RHODOCOCCUS SP. HDN3 ISOLATED FROM HERBICIDE/DIOXIN CONTAMINATED SOIL IN DANANG

Abstract

The dibenzofuran degrading bacterial strain HDN3 vias isolated from heavyherbicide/dioxin contaminated soil in a US former military base at Danang Airport. Colony ofHDN3 is orange, round, slight convex and 2 - 3 mm diameter after 7 days of incubation inmineral salt medium containing dibenzofuran. Cells of HDN3 strain were Gram-positive.Analysis of 16S rDNA sequence showed that strain HDN3 was closely related to Rhodococcusrhodochrous ATCC 27IT (98.4%), Rhodococcus sp. PA (97.3%), Rhodococcus sp. P7 (97,3), Rhodococcus pyridinivorans PDB9T (96,7%), Terrabacter sp. YK3 (96.7%) and also two dioxinand/or dibenzofuran Rhodococcus opacus SAOIOI (94%), Rhodococcus sp. YK2 (94%). Basedon morphological characteristics and analysis of 16S rRNA gene sequence, HDN3 strain shouldbe placed in genus Rhodococcus and named Rhodococcus sp. HDN3. A part of gene encodedangular dioxygenase were amplified from total DNA of HDN3 strain by using primer pair DIOXY-F and DIOXY-R, and showed high similar levels 99% to didA gene in Terrabacter sp.DBF63 and Rhodococcus sp. YK2