Insights into the microbial diversity and structure in a full-scale municipal wastewater treatment plant with particular regard to Archaea.

Grażyna Płaza,Jakub Hubeny,Monika Harnisz,Ewa Korzeniewska,Łukasz Jałowiecki,Dominika Głowacka,Lorenzo Brusetti

doi:10.1371/journal.pone.0250514

Abstract

Due to limited description of the role and diversity of archaea in WWTPs, the aim of the study was to analyze microbial community structures and diversities with particular regard to Archaea in the samples taken from different stages of the full-scale municipal wastewater treatment plant and effluent receiving water (upstream and downstream discharge point). Our study was focused on showing how the treatment processes influenced the Eubacteria and Archaea composition. Alpha and Beta diversity were used to evaluate the microbial diversity changes in the collected samples. Proteobacteria was the largest fraction ranging from 28% to 67% with 56% relative abundance across all samples. Archaea were present in all stages of WWTP ranged from 1 to 8%. Among the Archaea, two groups of methanogens, acetoclastic (Methanosarcina, Methanosaeta) and hydrogenotrophic methanogens (Methanospirillium, Methanoculleus, Methanobrevibacter) were dominant in the technological stages. The obtained results indicate that the treated wastewater did not significantly affect eubacterial and archaeal composition in receiving water. However, differences in richness, diversity and microbial composition of Eubacteria and Archaea between the wastewater samples taken from the primary and secondary treatment were observed.

Highlights

Despite the advantages of culture-dependent techniques, including low cost and the potential to combine with other methods, the availability of culture-based methods for studies of environmental microbes significantly reduces the research on microbial community structure in environmental ecosystems [1]
The results presented in this paper are the first to describe the diversity of microbial community structures with special attention to Archaea in various stages of technological process of full-scale municipal wastewater treatment plant (WWTP)
The results present differences in richness, diversity and microbial composition of Eubacteria and Archaea between the samples collected from the various technological stages

Summary

Introduction

Despite the advantages of culture-dependent techniques, including low cost and the potential to combine with other methods, the availability of culture-based methods for studies of environmental microbes significantly reduces the research on microbial community structure in environmental ecosystems [1]. Culture-independent molecular methods based on 16S rRNA genes and on sequencing of total DNA (metagenomic sequencing) have been developed to characterize the phylogenetic and functional diversity of microbial communities. The specific roles of these authors are articulated in the ‘author contributions’ section. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

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