耐冷氨氧化功能菌群强化人工湿地低温脱氮

针对冬季低温条件下人工湿地脱氮效率低的问题，将富集得到的耐冷氨氧化功能菌群固定化后投加到人工湿地中，探究生物强化对低温下人工湿地脱氮的强化效果及其微生物作用机制.结果表明，5℃条件下，梯度降温（R1）和梯度降温耦合选择性抑制（R2）条件下富集培养的耐冷氨氧化功能菌群强化处理的人工湿地的氨氮平均去除率分别为84%和88%，比对照组湿地分别提高24%和28%.高通量测序分析表明，富集得到的耐冷氨氧化功能菌群中优势菌种（相对丰度高达19.2%）为具有氨氧化功能的硝化螺旋菌（Nitrospira sp.），属于全程氨氧化菌，在氨氧化过程中起主要作用.微生物相对表达水平分析表明，两组生物强化人工湿地中氨氧化功能基因amoA的表达丰度分别为2.82×10⁸，8.22×10⁸拷贝数/克基质，显著高于对照组湿地的2.50×10⁷拷贝数/克基质.投加耐冷氨氧化功能菌群可以有效提高人工湿地脱氮效率.

Enhanced nitrogen removal of constructed wetland under low temperature based on cold resistant ammonia-oxidizing functional consortia

Aiming to solve the problems of decreased nitrogen removal efficiency of constructed wetland (CW) under the low temperature in winter, immobilization of the enriched cold resistant ammonia-oxidizing functional consortia was added into CW to explore its biological enhancement effect on nitrogen removal of CW under low temperature, as well as its microbial function mechanisms. Results showed that, at 5℃, the average ammonia removal rate of CW added with cold resistant ammonia-oxidizing functional consortia cultivated under gradient cooling (R1) and gradient cooling coupled selective inhibition (R2) were 84% and 88%, which were 24% and 28% higher than that in the control, respectively. High-throughput sequencing results revealed that Nitrospira sp., which belongs to complete ammonia oxidizing bacteria, was the dominant bacteria with the relative abundance up to 19.2%, and played the major role in the ammonia oxidation in CW. Analysis of microbial relative expression level showed that the expression abundance of ammonia oxidation gene amoA in the two groups of bio-enhanced constructed wetlands was 2.82×10⁸ and 8.22×10⁸copies/g matrix, which was significantly higher than that in the control, which was 2.50×10⁷copies/g matrix. Generally, the nitrogen removal efficiency of CW could be effectively improved by adding cold resistant ammonia-oxidizing functional consortia.