东北沼泽湿地土壤中氨氧化微生物活性和丰度研究

Activity and abundance of ammonia-oxidizing bacteria and ammonia-oxidizing archaea of marsh wetland soil in Northeast of China

为了研究东北典型沼泽湿地——三江湿地和扎龙湿地表层土壤中氨氧化微生物的活性和丰度,采用氯酸盐抑制亚硝酸盐氧化菌(Nitrite-oxidizing bacteria,NOB)和氨苄青霉素抑制氨氧化细菌(Ammonia-oxidizing bacteria,AOB)以及荧光定量PCR的方法,分析了生长季和非生长季氨氧化微生物的活性和丰度的关系。结果表明:在不同类型的湿地土壤中,pH值显著地影响湿地土壤中氨氧化古菌(Ammonia-oxidizing archaea,AOA)的潜在氨氧化活性(Potential ammonia oxidation activity,PAO)(P<0.01)。AOA的丰度值与PAO_(AOA+AOB)呈显著正相关(r=0.96,P<0.05),而与PAO_(AOA)不存在相关性(P>0.05)。三江湿地的毛苔草和小叶章土壤中的PAO_(AOA+AOB)、PAO_(AOA)、AOA丰度与AOB丰度,并无显著差异。研究表明植被的差异并没有影响土壤中氨氧化微生物的潜在氨氧化活性以及氨氧化微生物的丰度,但在抑制AOB活性之后毛苔草土壤中的PAO出现了显著的下降(P<0.05),表明AOB在毛苔草土壤中的氨氧化过程中发挥着重要作用。

In this study, chlorate and ampicillin were used as inhibitors to nitrite-oxidizing bacteria（NOB）and ammonia-oxidizing bacteria（AOB）, respectively. And combined with the quantitative polymerase chain reaction（q PCR）to test two different properties of typical marsh wetland topsoil in Northeast China, Sanjiang plain and Zhalong plain. The correlation of activity and abundance of AOA and AOB in growing season and non-growing season was analyzed. The results showed that the pH value could significantly affect the activity of AOA（P 0.01） in different types of wetland soils; The abundance value of AOA and PAO（AOA＋AOB）had significantly positive correlation（r=0.96, P〈0.05）, in turn, with its PAO（AOA）had no correlation（P〉 0.5）. The PAO（AOA＋AOB）and PAO（AOA）, the abundance of AOA and AOB of Sanjiang wetland had no significant difference between Calamagrostis angustifolia and Carex lasiocarpa, indicting the difference of plants would not affect the PAO and the abundance of ammonia-oxidizing microbial. However, after inhibited the activity of AOB, the PAO value emerged significantly decreased（P〈0.05）, which concluded AOB could play an important role in the ammonia oxidation process of Carex lasiocarpa.