中文摘要：

【目的】通过对一处经过长期使用贝壳砂进行改良的土壤中的反硝化细菌的多样性和细菌分离分析，研究该土壤中反硝化细菌的组成特征。【方法】采用454焦磷酸测序的方法分析了土壤样品中微生物群落的组成，选用Giltay培养基培养、鉴定从土壤中挑选的分离物的反硝化能力，并对具有反硝化能力的微生物进行了16S rRNA基因鉴定。【结果】该土壤样品中占据优势地位的为Proteobacteria、Acidobacteria、Bacteroidetes、Chloroflexi等门的微生物，属的水平上则有近70%尚未确立分类地位。所分离的细菌中，共得到12株厌氧条件下具有较高硝酸盐去除效率的微生物，分属Pseudomonas、Aeromonas、Serratia和Acinetobacter，均为γ变形菌纲的微生物。【结论】该土壤中具有较高的微生物多样性，包括很多未知类型的微生物和众多类型的反硝化细菌；分离到了11株具有反硝化能力的菌株，可用于该土壤的反硝化过程的进一步研究。

英文摘要：

[Objective] Analysis of the denitrifying bacteria composition in a long-term amended soil by pyrosequencing and isolating functional bacteria. [Methods] Microbial community structure was analyzed by 454 pyrosequencing of 16S rRNA gene, Giltay medium was used to cultivate and screen denitrifying bacteria from the isolates obtained from the soil, 16S rRNA genes of the detected denitrifying bacteria were also identified. [Results] Proteobacteria, Acidobacteria, Bacteroidetes, Chloroflexi were dominant in the soil sample and nearly 70% sequences were unclassified in genus level. Among 1 344 isolates, 12 isolates were found that could efficiently remove nitrate under anaerobic condition and were affiliated to Pseudomonas, Aeromonas, Serratia and Acinetobacter. [Conclusion] The results showed a high microbial diversity in the soil and most of them were unclassified bacteria. Eleven strains of denitrifying bacteria were identified via nitrate removal and gas formation. These strains could be used for studying the denitrification property.