阿特拉津降解菌株AD111的分离鉴定及其降解特性

Isolation, identification, and characterization of atrazine-degrading bacterial strain AD111

摘要:

【背景】玉豆轮作过程中，玉米田中长残留除草剂阿特拉津易对下茬大豆作物产生不良影响。【目的】从黑龙江省安达市的农田土筛选一株能适应该土壤环境生长的阿特拉津降解菌并研究其降解特性。【方法】利用富集培养法，分离、筛选一株阿特拉津高效降解菌并结合外观形态、生理生化及16S rRNA基因序列测定对其进行鉴定，通过单一变量法设置不同的碳源、pH、温度和阿特拉津浓度，研究降解菌株最佳发酵及降解条件。【结果】得到一株在BSM-G中能够以阿特拉津为唯一氮源生长的高效阿特拉津降解菌AD111，鉴定为马德普拉塔无色小杆菌(Achromobacter marplatensis)。菌株AD111降解阿特拉津的最适温度为35 ℃，最适pH为8.0，最佳碳源为蔗糖，24 h内对浓度为50 mg/L的阿特拉津降解率达到99.7%，对300 mg/L的阿特拉津降解率达到81.9%。【结论】降解菌AD111具有较好的环境适应及阿特拉津降解能力，为解决黑龙江偏碱土壤中阿特拉津残留提供了良好的候选菌株。

Abstract:

[Background] In maize-soybean rotation system, the residual atrazine in maize field may influence the next crop soybean. [Objective] To screen an atrazine-degrading strain from the field soil in Anda City, Heilongjiang Province and explore the degradation characteristics. [Methods] A highly efficient strain was isolated and screened by enrichment culture method, and identified based on morphological observation, physiological and biochemical determination, and 16S rRNA sequencing. Different carbon sources, pH, temperatures, and atrazine concentration were set to explore the optimal fermentation and degradation conditions with the simple variable method. [Results] A highly efficient atrazine-degrading strain AD111 was screened out, which used atrazine as the sole nitrogen source in basic salt medium-glucose (BSM-G). It was identified as Achromobacter marplatensis. The optimal temperature, pH, and carbon source for atrazine degradation by AD111 were 35℃, pH 8.0, and sucrose. Within 24 h, it degraded 99.7% and 81.9% of atrazine at 50 mg/L and 300 mg/L, respectively. [Conclusion] AD111 has exceptional environmental adaptability and atrazine-degrading ability, which can remove the atrazine residue in alkaline land in Heilongjiang Province.