养殖水体氨氮降解菌的分离与降解特性研究

Isolation and Identification of High Effective Bacteria Degrading Ammonia-nitrogen in Aquaculture Water and Its Biodegradation Characteristics

以（NH4）2SO4为唯一氮源，经富集培养、平板涂布分离及平板划线纯化、摇瓶复筛等方法，从当地养殖池水体中分离、筛选氨氮降解菌。根据形态学、生理生化特征分析，对其进行归属鉴定，并研究其降解特性。通过对初步鉴定归属为沙雷氏菌属（Serratia．sp），命名为N-2的氨氮降解菌降解特性的研究，得到其最适降解条件：N-2利用（NH4）：S04作唯一氮源时，最适碳源为蔗糖，降解温度为32—37℃，pH为7．0。在最适条件下，当NH4＋-N初始质量浓度为50mg／L时，该菌培养至72h氨氮降解率可达97．4％。结果表明，该菌为高效氨氮降解菌，这种土著微生物在修复富营养化水体方面有较好的应用前景。

To screen indigenous microorganisms of purificating aquaculture water, a high effective strain N - 2 degrading ammonia - nitrogen has been isolated from the local breeding pond water with （NH4）2SO4 as sole nitrogen source via enrichment culture, spread plate separation and streak plate purification steps. N - 2 was identified as Serratia. sp by the morphology, physiological and biochemical characteristics. The optimal conditions for growth and degradation as follows： 32 - 37℃, pH 7.0, sucrose as carbon source. The degrading rate of NH4＋ - N by N - 2 was over 97.4% within 72 h at initial concentration of NH4＋ - N was 50 mg/L. It indicated that N - 2 strain has good applica- tion prospects in eutrophic water remediation.