Wu Xiukun, Zhang Wei, Liu Guangxiu, Chen Tuo, Li Zhongqin
Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China.
Microorganisms. 2023 Nov 27;11(12):2871. doi: 10.3390/microorganisms11122871.
Glaciers retreating due to global warming create important new habitats, particularly suitable for studying ecosystem development where nitrogen is a limiting factor. Nitrogen availability mainly results from microbial decomposition and transformation processes, including nitrification. AOA and AOB perform the first and rate-limiting step of nitrification. Investigating the abundance and diversity of AOA and AOB is essential for understanding early ecosystem development. The dynamics of AOA and AOB community structure along a soil chronosequence in Tianshan No. 1 Glacier foreland were analyzed using qPCR and clone library methods. The results consistently showed low quantities of both AOA and AOB throughout the chronosequence. Initially, the copy numbers of AOB were higher than those of AOA, but they decreased in later stages. The AOB community was dominated by "Nitrosospira cluster ME", while the AOA community was dominated by "the soil and sediment 1". Both communities were potentially connected to supra- and subglacial microbial communities during early stages. Correlation analysis revealed a significant positive correlation between the ratios of AOA and AOB with soil ammonium and total nitrogen levels. These results suggest that variations in abundance and diversity of AOA and AOB along the chronosequences were influenced by ammonium availability during glacier retreat.
由于全球变暖而退缩的冰川创造了重要的新栖息地，特别适合于研究氮是限制因素的生态系统发育。氮的可用性主要源于微生物分解和转化过程，包括硝化作用。氨氧化古菌（AOA）和氨氧化细菌（AOB）进行硝化作用的第一步且是限速步骤。研究AOA和AOB的丰度和多样性对于理解早期生态系统发育至关重要。利用定量聚合酶链反应（qPCR）和克隆文库方法分析了天山一号冰川前缘土壤时间序列上AOA和AOB群落结构的动态变化。结果一致表明，在整个时间序列中，AOA和AOB的数量都很低。最初，AOB的拷贝数高于AOA，但在后期有所下降。AOB群落以“亚硝化螺菌属ME簇”为主，而AOA群落以“土壤和沉积物1”为主。在早期阶段，这两个群落都可能与冰上和冰下微生物群落相连。相关性分析表明，AOA和AOB的比例与土壤铵态氮和总氮水平之间存在显著正相关。这些结果表明，冰川退缩过程中，AOA和AOB丰度和多样性沿时间序列的变化受铵可用性的影响。
