黑土中阿特拉津降解细菌Z_9的分离鉴定及降解特性

研究利用富集培养的方法,从黑龙江省长期施用阿特拉津的玉米田(0～10cm)耕层土壤中筛选到以阿特拉津为唯一碳氮源的菌株Z9,其对阿特拉津14d的降解率可达77.7%。通过形态照片观察和生理生化特征测定,初步鉴定Z9菌为微杆菌属(Microbacterium sp).。结果表明,在100mg·L-1阿特拉津中对Z9的生长降解特性研究,接种量为3%,pH为7时生长和降解效果最好。摇床转速越大,菌株生长越好。摇床速度在120r·min-1,降解率最大。在最佳降解条件下,Z9对初始浓度为10、20、40、70、100mg·L-1的阿特拉津溶液的降解均符合一级降解动力学方程。降解半衰期分别为3.56、4.11、5.97、6.36、6.48d。

Isolation and its characteristics of atrazine degrading bacterium Z9 from black soil

From the corn soil (0-10 cm) of long-term applying atrazine in Heilongjiang Province, one strain that we named Z9 was obtained by enrichment culture. It used atrazine as sole carbon and nitrogen source, and its degradation rate got 77.7% after 14 d. By morphology and physiological and biochemical characteristics testing, the preliminary identification indicated that Z9 belonged to Microbacterium sp. When concentration of atrazine was at 100 mg·L-1, the growth and degradation characteristics of Z9 has been studied preliminarily. The results showed that when the dose was 3%, the pH was 7, the growth and degradation rate was the highest. The faster the rotational speed was, the higher the growth was. When the rotational speed was at 120 r·min-1, the degradation rate was the highest. Under the optimum condition, when the initial concentration were 10, 20, 40, 70, 100 mg·L-1, the degradation process of atrazine accorded with the first-order equation. Its half-life was 3.56, 4.11, 5.97, 6.36, 6.48 d, respectively.