云南地区热泉中氨氧化菌丰度对环境条件的响应

Abundance of Ammonia-Oxidizing Microorganisms in Response to Environmental Variables of Hot Springs in Yunnan Province, China

摘要:

摘要:【目的】研究热泉中的氨氧化菌对于理解全球氮循环作用至关重要，而人们对于热泉中环境条件对氨氧化菌丰度分布的影响还知之甚少。本研究旨在研究云南热泉中氨氧化菌的丰度以及热泉环境因子（例如：温度、氨浓度及pH等）对氨氧化菌丰度的影响。【方法】在所选取的热泉中，采集沉积物、菌席或泉华样品。使用RNA逆转录、定量聚合酶链式反应及荧光原位杂交等技术对样品中各微生物种群进行定量分析。【结果】所选取的热泉沉积物、菌席或泉华中微生物总量大约为108~109细胞/g。其中，氨氧化古菌（AOA）占样品中微生物总量的0.02~1.32%，而氨氧化细菌数量低于检测下限。地球化学参数和AOA相对丰度的相关性统计分析显示，氨氧化古菌相对丰度值与NH3 、NO2-、NO3-浓度和温度等具有统计学意义上的相关性，而其与Fe2+和及盐度无统计学意义上的相关性。【结论】在所调查的热泉中，氨氧化微生物种群主要由AOA组成，AOA在热泉中的氨氧化生物地球化学过程中起着重要作用。热泉中多个环境因子一起控制着AOA丰度在不同热泉中的分布特征，而某些环境因子，如盐度-和Fe2+浓度，可能不是控制AOA分布特征的关键因素。

Abstract:

Abstract: [Objective] Investigation of ammonia-oxidizing microorganisms (AOMs) in hot springs is of significant importance to understand global nitrogen cycling. However, we still know little about the abundance of AOMs in hot springs. In this research, the abundance of AOMs in thirteen hot springs located in Yunnan Province, China, and the effects of environmental variables (e.g. temperature, pH and ammonia concentration, and certain ions) on the AOM abundance were studied. [Methods] Microbial abundance in collected hot spring samples was determined by using an integrated approach including reverse-transcription quantitative polymerase chain reaction and catalyzed reporter deposition-fluorescence in situ hybridisation. [Results] Total biomass in the collected hot spring samples was 108-109 cells/g, among which ammonia-oxidizing archaea (AOA) occupied 0.02-1.32%, whereas no ammonia-oxidizing bacteria were detected. Statistical analysis indicated that AOA abundance was significantly（p<0.05）correlated with concentrations of NH3, NO2-, NO3-, pH and temperature, but not related (p>0.05) to salinity and concentrations of Fe2+ and salinity. [Conclusion] AOA were the major component of AOM in the studied hot springs, and play an important role in ammonia oxidation in hot springs. Multiple environmental variables (e.g. NH3, NO2-, NO3-, pH and temperature) were together controlling the AOA distribution among hot springs of different conditions, and some environmental variables, such as Fe2+ and salinity may not be the key factors for AOA in hot springs.