Degradation characteristics and identification and the degradation pathway of the atrazine-degrading strain DNS32

Abstract:

[Objective] The objective was to study the identification, degradation characteristics and the degradation pathway of the atrazine-degrading strain DNS32, and enrich the resources of atrazine-degrading bacteria. [Methods] Strain DNS32, which was isolated from black soil in this study, could utilize atrazine as the sole nitrogen source for growth, and its basic degradation characteristics were studied. The 16S rRNA gene phylogenetic analysis was used to identify of the strain DNS32. The degradation pathway was studied by degrading genes amplification and the measurement of the content of the final catabolite. [Results] The results showed that strain DNS32 had greater degradation capacity and could utilize certain amount of atrazine even under a relative low temperature. The 16S rRNA gene phylogenetic analysis showed that the 16S rRNA gene sequence of the strain DNS32 had a 99% similarity with that of Acinetobacter lwoffii. Atrazine-degrading genes trzN, atzB and atzC were amplified by PCR, and these genes enabled strain DNS32 decompose atrazine to cyanuric acid, in accordance with the degradation pathway of Arthrobacter aurescens TC1 proved by the measurement of the atrazine degradation rate and the content of the final catabolite. [Conclusion] This study enriched the resources of atrazine-degrading bacteria and provided useful informations to the study of the atrazine-degrading strains belonging to Acinetobacter.