| 摘要: |
| 菌株XH2是从虾池养殖中后期(50 d)水体环境中筛选的1株具有氨氮去除功能的菌株，经16S rDNA测序和Biolog生化鉴定，该菌株为玫瑰红红球菌(Rhodococcus rhodochrous)。分析发现，该菌株在盐度为5~45、pH为6.0~9.0、温度为15℃~45℃、通气量为1~2 L/min的条件下生长良好，菌量最高可达1.03×109 cells/ml。在盐度为25~45、pH为6.0~9.0、温度为15℃~30℃、通气量为1~ 2 L/min的条件下，菌株对氨氮的去除效果显著(P<0.05)，在第1~3天对培养液中氨氮的最高去除率可达90.0%~100.0%，而各实验组中，亚硝酸盐氮浓度无明显变化。结果显示，菌株XH2对盐度、pH、温度等主要环境因子具有良好的适应性，与大部分水产养殖池塘水体的盐度、温度、pH变动区间大体一致；其对水体氨氮的去除效果良好，可作为养殖池塘水体氨氮防控菌剂产品研发的备选菌株。 |
| 关键词: 玫瑰红红球菌 氨氮 理化因子 |
| DOI： |
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| Effects of Four Physical and Chemical Factors on the Ammonia Nitrogen Removal of Rhodococcus rhodochrous XH2 |
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TIAN Yajie1, CAO Yucheng1,2,3,4, HU Xiaojuan2,3,4, HUANG Xiaoshuai2,3,4, XU Yu2,3,4, XU Yunna2,3,4, LI Zhuojia2,3,4,5, WEN Guoliang1,2,3,4
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1.National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306;2.South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences;3.Key Laboratory of Fishery Ecologyand Environment, Guangdong Province;4.Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangzhou 510300;5.South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275
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| Abstract: |
| The accumulation of ammonia nitrogen in water is highly toxic to cultured aquatic animals. The microbiological method has received widespread attention as an efficient way to remove ammonia nitrogen in aquaculture because of its high efficiency and environment-friendliness. The genus Rhodococcus is a very diverse group of bacteria that can remove a variety of compounds, including ammonia nitrogen. Here, the strain XH2, which potently removes ammonia nitrogen, was isolated from aquaculture water during the middle to late (50 d) phase of shrimp cultivation. Its ecological adaptability and feasibility of use as a probiotic to improve aquaculture water quality was evaluated. According to the results of 16S rDNA sequencing and Biolog identification, XH2 was identified as Rhodococcus rhodochrous. Its growth performance and ammonia nitrogen removal efficacy were studied under different salinities (5, 15, 25, 35, and 45), pH (4.5, 6.0, 7.5, 9.0, and 10.5), temperatures (5, 15, 25, 35, and 45℃), and aeration levels (1~2 L/min). The results showed that XH2 had high adaptability to varied ranges of salinity (5~45), pH (6.0~9.0), temperature (15℃~45℃), and ventilation (1~2 L/min), with a maximum observed cell amount of 1.03×109 cells/ml. Specifically, the concentration of ammonia nitrogen in medium was reduced by 90.0%~100.0% during 1~3 d under the following conditions: salinity 25~45, pH 6.0~9.0, temperature 15℃~30℃ and ventilation volume 1~2 L/min (P<0.05). There was no significant difference in nitrite concentrations. Taken together, these data show that the XH2 strain possesses the physico-chemical properties of a suitable alternative in terms of salinity, pH, temperature, and ventilation, which can be applied to most aquaculture ponds for the prevention and control of ammonia nitrogen. |
| Key words: Rhodococcus rhodochrous Ammonia nitrogen Physical and chemical factors |
