Comparison of Prokaryotic Communities Associated with Different TOC Concentrations in Dianchi Lake

Cheng-Peng Li,Yong-Xia Wang,Wei Xiao,Xiao-Long Cui,Ya-Ping Li,Qing-Qing Huo,Chang-Qun Duan

doi:10.3390/w12092557

Abstract

The effect of total organic carbon (TOC) on the prokaryotic community structure in situ has been rarely known. This study aimed to determine the effect of TOC level on the composition and networks of archaeal and bacterial communities in the sediments of Dianchi Lake, one of the most eutrophic lakes in China. Microbial assemblages showed significantly associations with TOC. Moreover, relatively high and low TOC formed taxonomic differences in prokaryotic assemblages. According to the results, the most abundant bacteria across all samples were identified as members of the phyla Proteobacteria, Nitrospirae, Chloroflexi, Firmicutes and Ignavibacteriae. The dominant groups of archaea consisted of Euryarchaeota, Woesearchaeota DHVEG-6, Bathyarchaeota and WSA2. Lastly, the meta-analysis results highlighted that the low TOC (LT) prokaryotic community structure is larger and more complex compared to moderate TOC (MT). On the whole, the prokaryotic community structure is obviously distinct among groups with different TOC levels, and LT communities may interact with each other strongly in the Dianchi Lake sediment. This study can provide more insights into prokaryotic assemblages in eutrophic lake sediment and provide suggestions for the restoration and maintenance of sediment ecosystems.

Highlights

Microbial consortia harbored in the sediment are at the hub of ecological processes, which play a pivotal role in the biogeochemical cycling of nutrients, biotransformation and biodegradation of pollutants, as well as the restoration and maintenance of sediment ecosystems [1,2,3]
The sediment temperature values were relatively high at sites DC06 and DC07, while they were low at sites DC01 and DC02
Our study reported that the most bacteria across all samples were identified as members of the phyla Proteobacteria, Nitrospirae, abundant bacteria across all samples were identified as members of the phyla Proteobacteria, Nitrospirae, Chloroflexi, Firmicutes and Ignavibacteriae and the dominant groups of archaea consisted of Chloroflexi, Firmicutes and Ignavibacteriae and the dominant groups of archaea consisted of Euryarchaeota, Euryarchaeota, Woesearchaeota DHVEG-6, Bathyarchaeota and WSA2

Summary

Introduction

Microbial consortia harbored in the sediment are at the hub of ecological processes, which play a pivotal role in the biogeochemical cycling of nutrients, biotransformation and biodegradation of pollutants, as well as the restoration and maintenance of sediment ecosystems [1,2,3]. Insights into prokaryotic communities in lake sediment ecosystems can indicate the directions of ecosystem management and biodiversity preservation. It has been of particular interest to more comprehensively clarify the mechanisms driving the assembly and interactions of freshwater-sediment microbial communities [4,5,6,7]. Over the past few years, numerous studies reported that both variations in physicochemical properties and in biotic factors can form sediment ecosystems communities [8]. According to Swan et al (2010), salinity in the sediments of a California hypersaline lake impacts the distribution of bacteria and archaea [9]. Pollution levels act as significant environmental variables of bacterial communities

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