从养殖池塘中分离筛选具有高效降解氨氮和亚硝酸盐氮能力的异养硝化菌，并 进一步研究其组合菌群的硝化性能． 分别以 NH ₄ Cl 和 NaNO ₂ 为唯一氮源，从高密度养殖 池塘淤泥、水样和鱼体肠道样品中进行菌株分离筛选，通过 16S rDNA 测序进行菌株鉴 定，并在好氧条件下考察菌株去除氨氮和亚硝酸盐氮的能力;选择降解效果较好的菌株进 行定量组合培养，通过单因素实验对混合培养条件包括碳源类型、碳氮比(C/N)、盐度、初 始 pH 等进行优化;在最优条件下研究单一菌株、二元组合和三元组合去除氨氮的效果以 及亚硝态氮和硝态氮的积累情况． 分离得到 8 株异养硝化细菌，经异养硝化性能测试获得 3 株降解氨氮和亚硝态氮效果较好的菌株，分别为巨大芽孢杆菌 W3-1、枯草芽孢杆菌 YZN-2 和植物乳杆菌 HT1-1，72h 氨氮降解率分别为 71． 2%、61． 3% 和 60． 7%，亚硝态氮 降解率分别为 38． 7%、35． 6% 和 37． 6%． 经过对组合菌群培养优化后，得出以下结果:以 柠檬酸钠为碳源，C/N 为 20，NaCl 质量浓度为 5 g/L，初始 pH 值为 6 时，24 h 内的平均降 解速率达2． 05mg/(L·h ^－1 );单一菌株与二元和三元定量组合在培养前期 9 h 内氨氮降解 速率有显著差异，W3-1 单独培养的降解速率为1．61mg/(L·h ^－1 )，而 W3-1 + HT1-1 的降解 速率提高到2．51mg/(L·h ^－1 )，W3-1 + YZN-2 + HT1-1 的速率提高到2．49mg/(L·h ^－1 )． 由 上述结果可知，菌株 W3-1、YZN-2 和 HT1-1 脱氮能力较强，其中植物乳杆菌和芽孢杆菌 组合在前期有利于提高芽孢杆菌氨氮降解速率． 本研究的结果为污水处理工艺中硝化系 统的快速启动以及脱氮菌剂的开发提供了理论参考．

Heterotrophic nitrifier with high ammonium and nitrite nitrogen removal ability was isolated from the aquaculture pond，and the nitrification performance of mixed culture of multi-strains was studied． The strains were isolated from sediment，waters and intestinal tract of fish samples in the high density aquaculture ponds by enriching with NH ₄ Cl and NaNO ₂ as a sole nitrogen source respectively and identified by sequence analysis of 16S rDNA． Ammonium and nitrite nitrogen removal ability was investigated under aerobic conditions． The selected strains were quantitatively mixed to evaluate the ammonium removal efficiency under different culture conditions such as carbon source，C/N ratio，initial pH，and NaCl concentration． The nitrifying characteristics were investigated of single， pairwise，three-member microbial community under the optimal conditions． Eight heterotrophic nitrobacteria were isolated and three strains showed the higher ability of removing ammonium and nitrite nitrogen belonged to Bacillus megaterium (W3-1)，B． subtilis (YZN-2) and Lactobacterium plantarum subsp． (HT1-1)，respectively． The NH ₄ ⁺ -N removal efficiency was 71. 2%，61. 3% and 60. 7%，while NO ₂ ^－ -N removal efficiency was 38. 7%， 35. 6% and 37. 6%，respectively． After the optimization of mixed culture，the results show that under the condi- tions of sodium citrate as carbon source，C/N for 20，NaCl concentration for 5 g/L and pH 6，the mean ammoni- um removal rate is 2. 05 mg/ (L·h ^－1 ) in 24 hours． In the community of W3-1 + HT1-1 and W3-1 + YZN-2 + HT1-1，the ammonium removal rate is promoted by HT1-1 at the early stage，e． g． the average ammonium re- moval rate of W3-1 alone is 1. 61 mg/ (L·h ^－1 ) during first 9 h，while the rate of W3-1 + HT1-1 and W3-1 + HT1-1 + YZN-2 raise to 2. 51 mg/ (L·h ^－1 )，and 2. 49 mg/ (L·h ^－1 )，respectively． The above results in- dicate that the strains of W3-1，YZN-2 and HT1-1 show higher heterotrophic nitrification ability than others． The ammonium removal rate of B． subtilis is improved by combination with L． plantarum． The research provides necessary theoretical reference for the fast start of nitrification system in the sewage treatment process and the deve- lopment of nitrifier agents．