Seasonal
co-occurrence patterns of bacterial and eukaryotic phytoplankton
communities and ecological
effects of keystone taxa in an urban river
Jing Yang · Haiguang Pei · Junping Lv · Qi Liu · Fangru Nan · Xudong Liu
· Shulian Xie and Jia Feng
School of Life Science, Shanxi University, Taiyuan 030006, China
Corresponding author: Jia Feng
fengj@sxu.edu.cn
Running title: Co-occurrence of microbiota and environment
Abstract:
Microorganisms play a key role in
aquatic ecosystems. Recent studies have showed that some keystone taxa
in microbial communities can drive the changes in community composition
and function. However, most studies have focused on abundant taxa,
whereas rare taxa are neglected because of their low abundance.
Therefore, it is important to clarify the seasonal variation of
bacterial and microalgal communities and understand the synergistic
adaptation of these organisms to different environmental factors. We
investigated the bacterial and eukaryotic phytoplankton communities and
their seasonal co-occurrence patterns using16S and 18S rDNA sequencing
approach. Our results indicated that in eukaryotic phytoplankton
networks, spring and autumn networks had higher connectivity and
complexity, forming the highly stable community structure. The positive
interactions of bacterial network were significantly higher than the
negative interactions, indicating that more mutual cooperation can make
the microbial communities better
resist changes in the external environment, thereby maintaining the
stability of microbial network.
The
main genera identified as keystone taxa in bacterial networks werePseudomonas , Stenotrophobacter , Bosea , andHyphomicrobium , which were significantly related to many
predicted functions. The main
genera identified as keystone taxa in eukaryotic phytoplankton networks
were Monodus , Tetradesmus , Scenedesmus ,Monoraphidium ,
and Amphora , which were
affected by dissolved organic carbon, nitrate, nitrite, and phosphate,
changes in these environmental factors can affect the stability of
network. Through the co-occurrence patterns, we analyzed the internal
mechanism of interaction between bacteria and eukaryotic phytoplankton
and understood the potential importance of keystone taxa in ecological
processes such as carbon, nitrogen, and phosphorus dynamics.
Keywords:Seasonal
co-occurrence patterns; Bacteria and eukaryotic phytoplankton
communities; Keystone taxa; Ecological effect;
Urban
river