Microeukaryotic gut parasites in wastewater treatment plants: diversity, activity, and removal

Jule Freudenthal,Feng Ju,Kenneth Dumack,Helmut Bürgmann

doi:10.1186/s40168-022-01225-y

Abstract

BackgroundDuring wastewater treatment, the wastewater microbiome facilitates the degradation of organic matter, reduction of nutrients, and removal of gut parasites. While the latter function is essential to minimize public health risks, the range of parasites involved and how they are removed is still poorly understood.ResultsUsing shotgun metagenomic (DNA) and metatranscriptomic (RNA) sequencing data from ten wastewater treatment plants in Switzerland, we were able to assess the entire wastewater microbiome, including the often neglected microeukaryotes (protists). In the latter group, we found a surprising richness and relative abundance of active parasites, particularly in the inflow. Using network analysis, we tracked these taxa across the various treatment compartments and linked their removal to trophic interactions.ConclusionsOur results indicate that the combination of DNA and RNA data is essential for assessing the full spectrum of taxa present in wastewater. In particular, we shed light on an important but poorly understood function of wastewater treatment – parasite removal.6ehe_ZkZdE9fr2WhScWVWRVideo

Highlights

During wastewater treatment, the wastewater microbiome facilitates the degradation of organic matter, reduction of nutrients, and removal of gut parasites
The present study addresses this gap by analyzing a publicly available data set of shotgun metagenomic and metatranscriptomic data provided by Ju et al [28], who sampled microbial communities in various treatment compartments of Wastewater treatment plants (WWTPs) across Switzerland
We identified a total of 508,250 SSU rDNA sequences via metagenomics and 537,935 SSU rRNA sequences via metatranscriptomics and assigned these to 1947 and 1887 operational taxonomic units (OTUs), respectively

Summary

Introduction

The wastewater microbiome facilitates the degradation of organic matter, reduction of nutrients, and removal of gut parasites. The microbiome in wastewater treatment plants (WWTPs) includes prokaryotes and eukaryotes: fungi, protists, and microscopic metazoans Together, this wastewater community facilitates anaerobic denitrification and aerobic nitrification, as well as heterotrophic respiration and flocculation [1,2,3,4,5]. The abovementioned functions are fulfilled by the concerted actions of the entire WWTP microbiome, the vast majority of WWTP surveys focus merely on the In addition to their key role in regulating the WWTP microbial community, protists deserve more attention for another important reason: this microeukaryotic group includes many gut-associated taxa that are potentially harmful to humans and animals [12, 15]. Little is known about the mechanisms involved, including the role of predation

Methods

Results

Discussion

Conclusion