Temporal and Spatial Dynamics of Archaeal Communities in Two Freshwater Lakes at Different Trophic Status.

Yuyin Yang,Zhen Wu,Shuguang Xie,Yu Dai,Yong Liu

doi:10.3389/fmicb.2016.00451

Abstract

In either eutrophic Dianchi Lake or mesotrophic Erhai Lake, the abundance, diversity, and structure of archaeaplankton communities in spring were different from those in summer. In summer, archaeaplankton abundance generally decreased in Dianchi Lake but increased in Erhai Lake, while archaeaplankton diversity increased in both lakes. These two lakes had distinct archaeaplankton community structure. Archaeaplankton abundance was influenced by organic content, while trophic status determined archaeaplankton diversity and structure. Moreover, in summer, lake sediment archaeal abundance considerably decreased. Sediment archaeal abundance showed a remarkable spatial change in spring but only a slight one in summer. The evident spatial change of sediment archaeal diversity occurred in both seasons. In Dianchi Lake, sediment archaeal community structure in summer was remarkably different from that in spring. Compared to Erhai Lake, Dianchi Lake had relatively high sediment archaeal abundance but low diversity. These two lakes differed remarkably in sediment archaeal community structure. Trophic status determined sediment archaeal abundance, diversity and structure. Archaeal diversity in sediment was much higher than that in water. Water and sediment habitats differed greatly in archaeal community structure. Euryarchaeota predominated in water column, but showed much lower proportion in sediment. Bathyarchaeota was an important component of sediment archaeal community.

Highlights

Archaea might participate in biogeochemical cycling of carbon, nitrogen and sulfur (Hu et al, 2015; Zhang et al, 2015)
Planktonic archaeal populations can be an important component of prokaryotic community in freshwater lakes (Lehours et al, 2005; Auguet and Casamayor, 2008; Callieri et al, 2009), but their abundance and structure can vary considerably with both time and water depth (Pernthaler et al, 1998; Casamayor et al, 2000, 2001; Keough et al, 2003; Lehours et al, 2005, 2007; Callieri et al, 2009; Berdjeb et al, 2013; Vila-Costa et al, 2013; Li et al, 2015)
The density of planktonic archaeal 16S rRNA gene ranged from 1.03 ± 0.07 × 107 to 8.2 ± 0.48 × 107 copies per L water in Dianchi Lake, whereas waters in Erhai Lake had the archaeal community size of 6.75 ± 1.71 × 105 to 1.75 ± 0.06 × 108 16S rRNA gene copies per L water (Figure 1A)

Summary

Introduction

Archaea might participate in biogeochemical cycling of carbon, nitrogen and sulfur (Hu et al, 2015; Zhang et al, 2015). Archaeaplankton communities in different lacustrine ecosystems show the Archaeal Communities in Freshwater Lakes marked dissimilarity (Casamayor et al, 2000, 2001; Keough et al, 2003; Auguet and Casamayor, 2008; Vila-Costa et al, 2013). A number of environmental factors might collectively regulate freshwater lake archaeaplankton community (Berdjeb et al, 2013)

Objectives

Methods

Results

Conclusion