Annual periodicity in planktonic bacterial and archaeal community composition of eutrophic Lake Taihu.

Junfeng Li,Junyi Zhang,Liyang Liu,Zuhong Lu,Yucai Fan,Xuegong Zhang,Yunfeng Yang,Lianshuo Li

doi:10.1038/srep15488

Abstract

Bacterioplankton plays a key role in nutrient cycling and is closely related to water eutrophication and algal bloom. We used high-throughput 16S rRNA gene sequencing to profile archaeal and bacterial community compositions in the surface water of Lake Taihu. It is one of the largest lakes in China and has suffered from recurring cyanobacterial bloom. A total of 81 water samples were collected from 9 different sites in 9 different months of 2012. We found that temporal variation of the microbial community was significantly greater than spatial variation (adonis, n = 9999, P < 1e−4). The composition of bacterial community in December was similar to that in January, and so was the archaeal community, suggesting potential annual periodicity. Unsupervised K-means clustering was used to identify the synchrony of abundance variations between different taxa. We found that the cluster consisting mostly of ACK-M1, C111 (members of acIV), Pelagibacteraceae (alfV-A) and Synechococcaceae showed relatively higher abundance in autumn. On the contrary, the cluster of Comamonadaceae and Methylophilaceae (members of lineage betI and betIV) had higher abundance in spring. The co-occurrence relationships between taxa were greatly altered during the cyanobacterial bloom according to our further network module analysis.

Highlights

Lake Taihu, with an area of 2,338 square kilometers and an average depth of 1.9 meters[20], is the third largest freshwater lake in China
We are interested in the following scientific questions: (i) What the temporal patterns of bacterial and archaeal community compositions are; (ii) How the location variation of community composition is when compared to temporal variation; (iii) How the co-occurrence relationship between microbes changes with the development of cyanobacterial bloom
We explored the microbial community of Lake Taihu via targeted 16S rRNA gene sequencing

Summary

Introduction

Lake Taihu, with an area of 2,338 square kilometers and an average depth of 1.9 meters[20], is the third largest freshwater lake in China It is a typical shallow eutrophic lake and has been suffering from severe cyanobacterial bloom in recent years. Total nitrogen (TN) and total phosphorus (TP) are control factors of bloom formation and different ratios of TN and TP have different promotion effects[23,24,25] Those aimed at microbial community were mainly based on coarse-resolution technique like PCR-DGGE26–33, T-RFLP34–36. Dominating bacteria in both sediment and water are Alpha-, Beta-, Gamma- and Deltaproteobacteria, Actinobacteria and Bacteriodetes. We are interested in the following scientific questions: (i) What the temporal patterns of bacterial and archaeal community compositions are; (ii) How the location variation of community composition is when compared to temporal variation; (iii) How the co-occurrence relationship between microbes changes with the development of cyanobacterial bloom

Methods

Results

Conclusion