| 田雅洁,曹煜成,胡晓娟,黄小帅,徐煜,许云娜,李卓佳,文国樑.4种因子对玫瑰红红球菌XH2氨氮去除效果的影响.渔业科学进展,2018,39(6):164-172 |
| 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. |
