阿特拉津降解菌FM326(Arthrobacter sp.)的分离筛选、鉴定和生物学特性

Isolation, Screening and Identification of Atrazine-degrading Bacterium FM326(Arthrobacter sp.)

采集除草剂阿特拉津污染的土壤,通过直接涂布法和富集驯化培养分离法,分别获得6株和5株能够降解阿特拉津的细菌。通过降解效率和降解动态试验,筛选到1株高效降解阿特拉津的菌株FM326,该菌株能以阿特拉津为唯一的碳源和氮源生长,培养96h后对1000mg·L-1阿特拉津降解效率达到97%。通过生理生化鉴定和16SrDNA序列分析,菌株FM326鉴定为节杆菌属(Arthrobacter sp.)细菌。该菌株表现出最适生长温度30～35℃,最适生长pH值5～9,好氧生长的生长特性。

The triazine herbicide atrazine（2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine） is one of the most used pesticides. Atrazine is principally used for control of certain annual broadleaf and grass weeds, primarily in corn but also in sorghum, sugarcane, and other crops. Although atrazine has relatively low persistency in soil, its remanets have been found in many higher concentrations even years after application due to widespread use. Microbial remediation is an effective and economic method to control the environment that has been polluted by atrazine. From herbicide contaminated soil, 5 atrazine degrading bacterial strains were isolated by enrichment culture, and 6 atrazine-degrading bacterial strains were isolated by direct coating method. In the 11 strains, FM326 was screened out as the most highly efficient degradation bacteria by degradation test and could use atrazine as the sole carbon and nitrogen sources for growth. The degradation efficiency of strain FM326 was up to 97% within 96 hours while atrazine concentration was 1 000 mg·L-1. Strain FM326 was identified as Arthrobacter sp. according to physiological and biochemical tests and the phylogenic tree established by means of 16S rDNA sequencing. Moreover, strain FM326 was aerobic bacteria, its optimum temperature and pH value for growth was 30~35 ℃ and 5~9, respectively. Strain of highly efficient degrading atrazine was found from soils, and which provide a basis for the treatment of contaminated soils by atrazine for the further research.