污水处理系统中氨氧化古菌的富集培养以及性质

Cultivation and characterization of an ammonia oxidizing archaeon enriched from wastewater treatment plant

摘要:

摘要:【目的】从污水处理系统中富集培养氨氧化古菌，鉴定其系统发育地位，进行初步的形态观察以及生长和代谢特性研究。【方法】使用添加抗生素的自养培养基，通过连续传代的方法富集培养氨氧化古菌，使用多种分子生物学方法检验富集纯度和古菌单一性，鉴定其系统发育地位;通过扫描电镜观察菌体基本形态;利用生长和代谢曲线计算相关性质参数。【结果】氨氧化古菌HJ-2b富集培养成功，在体系中的纯度达到93%;经16S rRNA基因鉴定属于亚硝化球菌(Nitrososphaera)属，与Nitrososphaera sp. JG1 相似度为100%，但功能基因amoA的相似度仅为72%;HJ-2b细胞呈杆状，其最大比增长速率为0.43 d－1，最大比氨氧化速率为3.9 fmol/(cell·d)。【结论】HJ-2b富集物来源于污水处理系统，对于研究氨氧化古菌在该系统中的存在条件及其在污水脱氮方面的贡献有重要意义。

Abstract:

Abstract:［Objectives］ To enrich ammonia-oxidizing archaeon (AOA) from wastewater treatment plants，identify its phylogenetic status，morphology and determine its growth and ammonia oxidation rates． ［Methods］AOA was enriched in autotrophic medium containing antibiotics by using consecutive passage． The purity，uniformity and phylogenetic status of archaeal enrichment were determined with different molecular tools． The morphology was determined with scanning electron microscopy． The AOA growth andammonia oxidation rates were calculated from the corresponding experimental results.［Results］An AOA enrichment HJ-2b with purity of 93% was obtained． The similarity of its 16S rＲNA gene with Nitrososphaera sp．JG1 was 100%，suggesting it belonged to Nitrososphaera spp., although the similarity of amoA gene between these two species was only 72%． HJ-2b cell was rod-shaped，with the maximum specific growth rate of 0.43 d－1，the specific ammonia-oxidation rate of 3. 9 fmol/(cell·d).［Conclusions］HJ-2b has great significance in studying the occurrence and contribution of AOA in wastewater treatment.