| 摘要: |
| 实验从海水螺旋藻培养体系中分离获得一株嗜碱兼性好氧反硝化菌，通过观察细菌形态以及16S rRNA基因序列的同源性分析，鉴定该菌株为海杆菌属，命名为Marinobacter sp. B3。为明确该海杆菌的反硝化性能及氮转化途径，研究开展了溶解氧(DO)，碳氮比(C/N)，pH和温度等不同单因素对反硝化性能影响实验和氮平衡实验。单因素影响实验结果表明，当硝酸钾(KNO3)作为唯一氮源，NO3--N的初始浓度为100 mg/L，盐度32‰，振荡速度为150 r/min(初始DO质量浓度是5.6 mg/L)，C/N=10，pH=8.0±0.2，温度为35℃时，可获得最大脱氮效果。此条件好氧环境下，反应48 h后，NO3--N去除率为99.89%，并且无NO2--N积累，72 h后，DOC去除率为95.13%，TN去除率为94.83%；相同条件厌氧环境下，反应48 h后，NO3--N去除率为93.80%，72 h后，DOC去除率为92.07%，TN去除率为99.18%。氮平衡实验结果得出，在好氧环境下，有20.11%的NO3--N转化为胞内氮，5.58 mg/L的NO3--N转化为其他形态(NO2--N，NH4+-N和有机氮)，74.72%转化为N2释放；厌氧环境下，有26.65%的NO3--N转化为胞内氮，72.86%的NO3--N转化为气态产物释放。结果表明，Marinobacter sp. B3在好氧条件以及厌氧条件下，48 h对NO3--N的去除率分别为99.89%，93.80%，具有较好的反硝化脱氮能力，且在好氧条件下NO3--N去除效率更高，在海水工厂化循环水养殖尾水处理方面具有良好的应用前景。 |
| 关键词: 反硝化作用 循环水养殖 生物脱氮 养殖尾水处理 |
| DOI：10.11693/hyhz20230900191 |
| 分类号: |
| 基金项目:国家自然科学基金青年基金;山东省自然科学基金青年项目；中国水产科学研究院基本科研业务费资助 |
附件 |
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| ISOLATION AND IDENTIFICATION OF AN ALKALOPHILIC FACULTATIVE AEROBIC DENITRIFICATION STRAIN MARINOBACTER SP. B3 AND ITS DENITRIFICATION PERFORMANCE |
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teng yu1, wang lu2, wang zhan ying1, cui zheng guo1, qu ke ming1, gong wei man1, liu shu kai1, cui hong wu1
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1.State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong;2.Laoshan Laboratory, Qingdao
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| Abstract: |
| Experimental isolation of an alkaliphilic denitrifying bacterial fine from a seawater Spirulina culture system. Through 16S rRNA identification and BLAST homology analysis, the genus was identified as Marinobacter, and named Marinobacter sp. B3. In order to clarify the denitrification performance and nitrogen conversion pathway of the sea bacillus, the present study was carried out to investigate the effects of different single factors, such as dissolved oxygen (DO), carbon/nitrogen ratio (C/N), pH and temperature, on denitrification performance and nitrogen balance experiment. The results of single-factor experiments showed that when potassium nitrate (KNO3) was used as the only nitrogen source, the initial concentration of NO3--N was 100 mg/L, the salinity was 32‰, the oscillation speed was 150 r/min (the initial DO mass concentration was 5.6 mg/L), C/N=10, pH=8, and the temperature was 35°C, the maximum nitrogen removal effect could be obtained. Under this aerobic environment, the NO3--N removal rate was 99.89% after 48 h of reaction, and there was no NO2--N accumulation. After 72 h, the removal rate of DOC was 95.13% and the removal rate of TN was 94.83%. Under the same anaerobic conditions, the NO3--N removal rate was 93.80% after 48 h, after 72 h, the DOC removal rate was 92.07% and TN removal rate was 99.18%. The results of nitrogen balance experiments showed that under aerobic environment, 20.11% of NO3--N was converted to intracellular nitrogen, 5.58 mg/L NO3--N was converted to other denitrification products (NO2--N, NH4+-N and organic nitrogen), and 74.72% was converted to N2 released. Under anaerobic conditions, 26.65% of NO3--N is converted to intracellular nitrogen, and 72.86% of NO3--N was converted to gaseous products for release. The results showed that Marinobacter sp. B3 had a better denitrification and denitrogenation capacity with 99.89% and 93.80% NO3--N removal for 48 h under aerobic as well as anaerobic conditions, respectively, and the NO3--N removal efficiency was higher under aerobic conditions， which has a good application prospect in the treatment of seawater factory recirculating water aquaculture tail water. |
| Key words: denitrification recirculating aquaculture biological denitrification aquaculture tail water treatment |