阿特拉津降解菌ADH-2的分离、鉴定及其特性研究

从长期施用阿特拉津的玉米地中采集土样，通过富集培养的方法分离出一株能以阿特拉津为唯一碳、氮源生长的细菌ADH-2，结合生理生化特陛及16SrRNA基因的相似性分析将其初步鉴定为节杆菌属（Arthrobacter sp．）。该菌在10h内对100mg·L-1阿特拉津的降解率为99．9％。外加氮源能促进菌株的生长，但对阿特拉津的降解有轻微的抑制作用。外加蔗糖和葡萄糖能显著促进菌株的生长，但对阿特拉津的降解表现出显著的抑制。而淀粉既能促进菌株的生长又能促进阿特拉津的降解。对其降解基因的初步研究显示，该菌含有trzN、atzB和atzC3个阿特拉津降解相关基因。通过与本实验室另外两株阿特拉津降解菌比较，菌株ADH-2具有更好的应用潜力。

Isolation,Identification and Characterization of an Atrazine-degrading Bacteria ADH-2

Atrazine is a triazine group of pesticide used for the control of weeds in crops such as sorghum, maize, sugarcane, citrus, etc. Although atrazine has relatively low persistency in soil, its remnants has been found in much higher .concentrations even years after application due to widespread use. Bioremediation is an effective and economic method to treat the environment that has been polluted by atrazine. So researchers paid much attention in this area. Most of this research focus on the isolating and characterizing bacteria with abilities to degrade atrazine. In the present study, a bacterial strain ADH-2 capable of utilizing atrazine as sole nitrogen and carbon source was isolated from soil samples collected from maize field suffered long-time application of atrazine by enrichment method. It was preliminarily identified as Arthrobacter sp. according to its physiological-biochemical characteristics and the similarity analysis of its 16S rRNA gene sequence （GeneBank Accession No.EF373977 ）. Strain ADH-2 could degrade 99.9% of 100 mg· L-1 atrazine within 10 h. Adding extra nitrogen source promoted the growth of strain ADH-2, but inhibited the degradation of atrazine slightly. The addition of glucose and sucrose showed a distinguished promoting effect to the growth and inhibitory effect to the degradation, while starch could promote both the growth and degradation. The atrazine-degrading related genes of ADH-2 were the combination of trzN, atzB and atzC. Compared with the other two atrazine-degrading bacterium isolated in the lab, ADH-2 showed good potentials in application.