阿特拉津降解菌株DNS32的降解特性及分类鉴定与降解途径研究

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

摘要:

【目的】研究阿特拉津降解菌株DNS32的菌种分类、降解特性及降解途径, 丰富阿特拉津降解菌菌种资源。【方法】在长期施用阿特拉津的东北地区寒地黑土中筛选出一株以阿特拉津为唯一氮源生长的降解菌株DNS32, 测定其基本降解特性, 通过16S rRNA序列分析进行分类鉴定, 并利用阿特拉津降解基因PCR扩增技术及降解产物生成量的测定, 进一步揭示其降解途径。【结果】实验结果发现DNS32菌株具有较好的降解能力, 且在相对较低温度下也具有一定的降解能力。16S rRNA序列分析结果表明DNS32与鲁氏不动杆菌 (Acinetobacter lwoffii) 16S rRNA序列同源性高达99%。成功地扩增降解基因trzN、atzB及atzC, 实验结果表明DNS32遵循Arthrobacter aurescens TC1的降解模式, 可将阿特拉津降解为氰尿酸, 降解产物的生成量测定也证明了这一点。【结论】实验结果丰富了阿特拉津降解菌菌种资源, 为不动杆菌属的阿特拉津降解菌研究提供了参考。

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.