Fluoride contributes to the shaping of microbial community in high fluoride groundwater in Qiji County, Yuncheng City, China

Xin Zhang,Xuesong Luo,Yanxin Wang,Chengcheng Li,Xubo Gao

doi:10.1038/s41598-019-50914-6

Xin Zhang, Xuesong Luo + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-50914-6

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Abstract

As a toxic element, excessive amounts of fluoride in environment can be harmful because of its antimicrobial activity, however little is known about the relationship between fluoride and the bacterial community in groundwater systems. Here, we use samples from a typical fluorosis area to test the hypothesis that fluoride concentration is a fundamental structuring factor for bacterial communities in groundwater. Thirteen groundwater samples were collected; high-throughput 16S rRNA gene sequencing and statistical analysis were conducted to compare the bacterial community composition in individual wells. The results showed that Proteobacteria, with most relative abundance in groundwater, decreased along the groundwater fluoride concentration. Additionally, relative abundances of 12 families were also statistically correlated with fluoride concentration. The bacterial community was significantly explained by TOC (P = 0.045) and fluoride concentration (P = 0.007) of groundwater. This suggests that fluoride and TOC likely plays an important role in shaping the microbial community structure in these groundwater systems. Our research suggest that fluoride concentration should be taken into consideration in future when evaluating microbial response to environmental conditions in groundwater system, especially for fluoride rich groundwater.

Highlights

Fluoride is a toxic element that can cause fluorosis to organisms[1,2] whether excessive or deficient
The positive correlation between fluoride and total phosphorus (TP) may partly due to the contamination of the phosphatic fertilizer and the competitive adsorption by PO43− which could cause the desorption of fluoride from mineral/organic matter surfaces within the groundwater system[61]
It is suggested that the concentration of fluoride in groundwater is under the control of natural water-sediments rock interactions in natural groundwater systems[62]

Summary

Introduction

Fluoride is a toxic element that can cause fluorosis to organisms[1,2] whether excessive or deficient It has been identified as a fundamental factor impacting microbial activity and communities in environment[3,4] due to its potential antimicrobial activity[5,6]. The negative impact of fluoride on soil microorganisms was quantified by Rao and Pal[16], who reported that elevated fluoride concentrations (380–1803 mg/g soil) were found to inhibit microbial growth and activity and decomposition of organic matter. The presence of fluoride, especially in amounts significantly exceeding its natural concentrations in soil, inhibits microbial growth and the decomposition of organic matter[18,19,20]. The aim of this study is (i) to investigate the microbial community in groundwater of the area; (ii) to discern which environmental parameters significantly influence the microbial community at the phylum, family and OTU levels; and (iii) to discuss the potential effects of F/[F] on the groundwater microbial community

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