Ammonia-oxidizing archaea and bacteria in water columns and sediments of a highly eutrophic plateau freshwater lake

Abstract

Both ammonia-oxidizing archaea (AOA) and bacteria (AOB) can play important roles in the microbial oxidation of ammonia nitrogen in freshwater lake, but information on spatiotemporal variation in water column and sediment community structure is still limited. Additionally, the drivers of the differences between sediment and water assemblages are still unclear. The present study investigated the variation of AOA and AOB communities in both water columns and sediments of eutrophic freshwater Dianchi Lake. The abundance, diversity, and structure of both planktonic and sediment ammonia-oxidizing microorganisms in Dianchi Lake showed the evident changes with sampling site and time. In both water columns and sediments, AOB amoA gene generally outnumbered AOA, and the AOB/AOA ratio was much higher in summer than in autumn. The total AOA amoA abundance was relatively great in autumn, while sediment AOB was relatively abundant in summer. Sediment AOA amoA abundance was likely correlated with ammonia nitrogen (rs = 0.963). The AOB/AOA ratio in lake sediment was positively correlated with total phosphorus (rs = 0.835), while pH, dissolved organic carbon, and ammonia nitrogen might be the key driving forces for the AOB/AOA ratio in lake water. Sediment AOA and AOB diversity was correlated with nitrate nitrogen (rs = -0.786) and total organic carbon (rs = 0.769), respectively, while planktonic AOB diversity was correlated with ammonia nitrogen (rs = 0.854). Surface water and sediment in the same location had a distinctively different microbial community structure. In addition, sediment AOB community structure was influenced by total phosphorus, while total phosphorus might be a key determinant of planktonic AOB community structure.

Diversity and abundance of comammox bacteria in the sediments of an urban lake

“…The nitrogen content of many urban lakes in the middle and lower reaches of the Yangtze River in China is usually high (Chen et al ; Wu et al ; Hou et al ). This high nitrogen concentrations could change the community structure of the AOA and AOB (Yang et al ). However, the existence and diversity of comammox bacteria in these urban lakes, and their relationships with other ammonia‐oxidizing micro‐organisms, are still unclear.…”

Environmental factors, but not abundance and diversity of nitrifying microorganisms, explain sediment nitrification rates in Yangtze lakes

“…Archaeal and bacterial amoA genes have been frequently used as molecular markers to examine the community structure of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in sediments and soils. [13][14][15][16] Microbially mediated nitrication generally occurs in the presence of oxygen in lake sediments and varies greatly across spatial and temporal scales. 17 Sediment nitrication rates are strongly inuenced by local water quality and sediment properties, including NH 4 + availability and organic matter.…”

Vertical and seasonal distribution of picoplankton and functional nitrogen genes in a high‐altitude warm‐monomictic tropical lake

“…These microorganisms oxidise NH 4 + to NO 2 − by using the ammonia monooxygenase enzyme, the α‐subunit of which is encoded by the amoA gene, a common genetic marker for nitrification (Rotthauwe, Witzel, & Liesack, ). The ecological importance of AOA and AOB communities has been investigated in a variety of freshwater ecosystems, such as rivers (Liu, Huang, Sun, Xu, & Xu, ; Magalhaes, MacHado, & Bordalo, ), lakes (Hou et al., ; Yang et al., ), reservoirs (Hugoni et al., ), and wetlands (Sims et al., ; Wang, Feng, Ma, & Gu, ). In oligotrophic, high‐altitude lakes, studies have shown that planktonic ammonia‐oxidising communities can vary with sampling site and time (Auguet, Nomokonova, Camarero, & Casamayor, ; Hayden & Beman, ; Hu et al., ; Vissers et al., ).…”