中文摘要：

利用从南四湖人工湿地中分离的一株具有良好脱氮作用的反硝化细菌XP1,分别接种于湿地植物芦竹、芦苇和香蒲的根际土壤,考察菌株XP1对3种植物的强化脱氮作用,并利用PCR-DGGE（变性梯度凝胶电泳）考察强化脱氮过程中菌株XP1在3种植物根际土壤微生物中的变化.结果表明：模拟湿地在未强化脱氮时,3种植物湿地在相同条件下脱氮能力大小顺序为芦竹〉芦苇〉香蒲;3种植物的根际土壤所含微生物种类基本相同,所含微生物总量顺序为芦竹〉芦苇〉香蒲,其中土著XP1菌株在芦竹、芦苇和香蒲根际土壤微生物中的含量比值约为1.5∶1.3∶1.加入菌株XP1强化脱氮后,香蒲、芦苇、芦竹3种植物湿地总氮去除率分别由14%,56%和56%提高至98%以上,强化脱氮作用明显;含氮废水ρ（TN）降至《地表水环境质量标准》（GB 3838—2002）Ⅲ类水质要求〔ρ（TN）≤1 mg/L〕时,3种植物根际土壤中的微生物种群数及微生物总量都有所下降,其中菌株XP1在3种植物根际土壤中的含量分别下降了40%,53%和67%,但根际细菌菌群结构未发生较大变化.

英文摘要：

A denitrifying bacterial strain named XP1 with good denitrification properties was isolated from the constructed wetland of Nansi Lake.To study the enhanced denitrification of XP1 in the rhizosphere soils of three plants（Arundo donax,Phragmites australis and Typha）,the bacterium strain XP1 was inoculated into the rhizosphere soil of the three plants.The change of XP1 in the rhizosphere soil microorganism of the three plants in the course of enhanced denitrification was investigated by polymerase chain reaction and denaturing gradient gel electrophoresis（PCR-DGGE）.The results showed that without the enhanced denitrification for simulated wetlands,the order of nitrogen removal capacity in the three plant wetlands was Arundo donax Phragmites australis Typha under the same conditions.The quantitative order of the dominant microorganisms around the three plants was Arundo donax Phragmites australis Typha,although there was no obvious difference in the variety of microorganisms in the rhizosphere soil of the three plants.The ratio of indigenous strain XP1 in the rhizosphere soils of the three plants was 1.5∶1.3∶1.Compared to the control group,the enhanced denitrification of the three plants were increased from 14%,56%,56% to more than 98%,respectively,which meant the XP1 had a significant enhancement in denitrification.When ρ（TN） of the wetland was less than that of the Class Ⅲ criterion in the Environmental Quality Standards for Surface Water of China（ρ（TN）≤1 mg L）,the diversity and quantities of the microorganisms in the three plants＇ rhizosphere soils decreased,though there was no marked change in the microbial community structure.For strain XP1,the quantities in the rhizosphere soils of the three plants decreased by up to 40%,53% and 67%,respectively.