Potential correlated environmental factors leading to the niche seg- regation of ammonia-oxidizing archaea and ammonia-oxidizing bac- teria: A review

Abstract

Ammonia oxidation is an important step of the nitrogen cycle and was considered to be conducted only by ammonia-oxidizing bacteria (AOB) for a long time. The discovery of ammonia-oxidizing archaea (AOA) caused consideration of the relative contributions of these two functional groups in different niches and factors resulting in their niche segregation. Previous studies showed that some environmental factors may correlate to the abundance and distribution of AOA and AOB, including ammonia/ammonium concentration, pH, organic matters, oxygen concentration, temperature, salinity, sulfide concentration, phosphate concentration, soil moisture and so on. Despite extensive studies conducted on ecology of AOA and AOB to find key environmental factors dominating niche segregation between AOA and AOB, few studies were conducted to explore the interrelationship among environmental factors. In this review, five main environmental factors which may be related to each other were selectively reviewed independently, including ammonia concentration, pH, temperature, oxygen concentration and organic matters. Furthermore, potential interrelationship among environmental factors was proposed.

High soilpHenhances the network interactions among bacterial and archaeal microbiota in alpine grasslands of the Tibetan Plateau

“…1B and S7B); this might be associated with the prevalence of archaea in extreme environments (Cavicchioli, 2006) and their functional diversification (e.g., ammonia oxidation, methane metabolism and organic matter degradation) (Orphan et al ., 2002; Könneke et al ., 2005; Lloyd et al ., 2013). Moreover, compared with AOB, AOA have a higher affinity for the substrate and oxygen; therefore, the latter group could survive under oligotrophic conditions during the biogeochemical cycles of carbon and nitrogen (Liu et al ., 2017). We also revealed that the associations were stronger between kingdoms than within a kingdom for archaeal taxa in the Tibetan alpine grasslands (Fig.…”

“…Alpine grassland ecosystems have two dominant vegetation types: alpine steppes (characterized by low MAP, oligotrophic conditions and high soil pH), and alpine meadows (characterized by high MAP, copiotrophic conditions and low soil pH; Zhang, 1988). Bacterial and archaeal communities in N‐ and P‐limited alpine grasslands are dominated by oligotrophic clades, such as Actinobacteria , Acidobacteria and AOA (Fierer et al ., 2007; Yang et al ., 2008; Liu et al ., 2017; Ma et al ., 2019). Therefore, soil bacteria and archaea have stronger connections in alpine steppes with oligotrophic conditions and high soil pH.…”

Increasing soil pH enhances the network interactions among bacterial and archaeal microbiota in alpine grasslands of the Tibetan Plateau

“…The presence of Thaumarchaeota as a dominant archaeal phylum might be explained by three main factors. First, compared with ammonia-oxidizing bacteria, ammonia-oxidizing archaea have a higher affinity for substrate and oxygen; therefore, the latter group could survive under oligotrophic conditions during the biogeochemical cycles of carbon and nitrogen [38]. Second, unlike ammonia-oxidizing bacteria, ammonia-oxidizing archaea assimilate CO 2 via an energy-saving method (the 3-hydroxypropionate/4hydroxybutryrate pathway) for autotrophic growth, and thereby use organic carbon sources directly [39,40].…”

“…The maps showed that soil bacterial and archaeal taxa in the alpine steppe (high soil pH) had closer relationships than in the alpine meadow (low soil pH). One plausible explanation for this observation is that the bacterial and archaeal communities in N-and P-limited alpine grasslands [55,56] are dominated by oligotrophic clades such as Actinobacteria, Acidobacteria, and ammonia-oxidizing archaea [38,57]. Therefore, soil bacterial and archaea have stronger connections in the alpine steppe (oligotrophic conditions and high soil pH) to resist pressure caused by an energy deficit [30].…”

Pattern of Research Trend Emerging from Small Data

“…Further examination of the published articles in this journal indicated that the topics of interest to readers the most by this journal are on enzymes, the protein structure of the metal center of a dehalogenase hydrolyzing chlorothalonil (Chen et al, 2010) and a low-temperature endo-β-1,4-mannase from Bacillus subtilis TD7 with expression in E. coli (Li et al, 2018); the evolutionary relationship between ammoniaoxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) (Liu et al, 2017); and the current plastic issue to our society (Gu, 2017). The immediate following these with the highest attention include inhibition of sulfate-reducing activity in oilfield (Liu et al, 2016) and bioleaching (Maulani et al, 2016).…”