4种理化因子对菌株XH1硝化效果的影响

Effects of four physical and chemical factors on the nitrification activity of strain XH1

摘要:

【背景】基于硝化菌群的富集培养技术可高效稳定地去除养殖水体中的有害氮素，而当前在水产养殖领域有关硝化菌群定向培育及硝化功能菌株的研究较少。【目的】研究不同盐度、pH、温度、通气量条件下硝化菌群分离菌株XH1的生长及其对氨氮和亚硝氮的去除效果。【方法】设置不同梯度的盐度、pH、温度、通气量条件，通过计数菌量、测定氨氮及亚硝氮的浓度变化，比较不同条件下菌株XH1的生长及其对氨氮和亚硝氮的影响。【结果】菌株XH1可在盐度5‰?35‰、pH 6.0?9.0、温度15?45 °C和通气量0.5?1 V/(V·min)的条件下生长良好，菌量最高可达2.34×109 cells/mL；在盐度5‰?35‰、pH 6.0?9.0、温度15?30 °C、通气量0.5 V/(V·min)的条件下，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86%?97%，但培养液中的氨氮浓度先降后升；对亚硝氮的最高去除率达68%。【结论】菌株XH1对盐度、pH、温度等主要环境因子具有良好的适应性，其对水体氨氮的去除效果良好，可作为中低盐度养殖池塘水体氨氮防控菌剂产品研发的备选菌株。

关键词:硫氧化柠檬胞菌，硝化，氨氮，理化因子

Abstract:

[Background] The enrichment and culture technology based on the nitrifying bacterial community show the efficiency and stability in removing ammonia nitrogen, nitrite nitrogen and other harmful nitrogen from the aquaculture water. However, only a few studies are available on nitrifying functional strains for the targeted cultivation of nitrifying bacterial community in aquaculture. [Objective] To study the effects of salinity, pH, temperature and ventilation on the growth and nitrification activity of strain XH1 isolated from nitrifying bacterial community. [Methods] Different gradients of salinity, pH, temperature and ventilation were assayed. The growth of strain XH1 and the corresponding removal effect on ammonia and nitrite nitrogen were analyzed by counting the number of bacteria and measuring the concentrations of ammonia and nitrite nitrogen, respectively. [Results] Strain XH1 could grow well under the conditions of salinity 5‰?35‰, pH 6.0?9.0, temperature 15?45 °C and ventilation 0.5?1 V/(V·min). The maximum content of bacteria reached the level of 2.34×109 cells/mL. Under the condition of salinity 5‰?35‰, pH 6.0?9.0, temperature 15?30 °C, and ventilation capacity 0.5 V/(V·min), the removal efficiency of ammonia nitrogen was significant (P<0.05). The highest removal rate of ammonia nitrogen in the culture solution could reach 86%?97% on 1?3 d, but then the concentration of ammonia nitrogen increased slightly in the following days. In addition, the highest removal rate of nitrite nitrogen was up to 68%. [Conclusion] The strain XH1 had a good adaptability to major environmental factors such as salinity, pH, and temperature. With the excellent removal ability on ammonia nitrogen, strain XH1 could be used as an alternative strain for the agents’ research on harmful nitrogen prevention and control in medium-low-salinity aquaculture ponds.

Key words:Citreicella thiooxidans, Nitrification, Ammonia nitrogen, Physical and chemical factors