Faecal pollution affects abundance and diversity of aquatic microbial community in anthropo-zoogenically influenced lotic ecosystems

Abstract

The aquatic microbiota is known to be an important factor in the sustainability of the natural water ecosystems. However, the microbial community also might include pathogens, which result in very serious waterborne diseases in humans and animals. Faecal pollution is the major cause of these diseases. Therefore, it is of immense importance to assess the potential impact of faecal pollution, originating from both anthropogenic and zoogenic sources, on the profile of microbial communities in natural water environments. To this end, the microbial taxonomic diversity of lotic ecosystems in different regions of Norway, representing urban and rural areas, exposed to various levels of faecal pollution, was investigated over the course of a 1-year period. The highest microbial diversity was found in rural water that was the least faecally polluted, while the lowest was found in urban water with the highest faecal contamination. The overall diversity of the aquatic microbial community was significantly reduced in severely polluted water. In addition, the community compositions diverged between waters where the dominant pollution sources were of anthropogenic or zoogenic origin. The results provide new insight into the understanding of how faecal water contamination, specifically that of different origins, influences the microbial diversity of natural waters.

Seasonal dynamics of lotic bacterial communities assessed by 16S rRNA gene amplicon deep sequencing

“…The bacterial community compositions were investigated in a Norwegian rural creek named Grytelandsbekken (Fig. 1), which was previously characterised as a lotic ecosystem with relatively low levels of anthropogenic faecal pollution and a very high microbial diversity and richness profile 21 . The amplicon libraries were prepared on the extracted genomic DNA from the lotic water samples.…”

“…The concentration and quality of the purified DNA was analysed on the NanoDrop Spectrophotometer (Thermo Fisher Scientific, Wilmington, USA). Five nanograms of purified DNA was used in PCR to prepare an amplicon library using the NEXTflex 16S V4 Amplicon-Seq Kit 2.0 (Bioo Scientific Corporation, Austin, TX, USA), following the provided protocol, which has previously been described in detail 21 . The applied specific 16S V4 forward primer (5′-GACGCTCTTCCGATCTTATGGTAATTGTGTGCCAGCMGCCGCGGTAA-3′) and reverse primer (5′-TGTGCTCTTCCGATCTAGTCAGTCAGCCGGACTACHVGGGTWTCTAAT-3′) were provided by the manufacturer and included in the sequencing kit.…”

“…S1). Most of them are affiliated to Proteobacteria, which are ubiquitous, persistent and prevalent in freshwater ecosystems under various environmental conditions 16,20,21 . To focus in on the population discrepancy of the bacterial community between cold and warm seasons, a linear discriminant analysis (LDA) effect size (LEfSe) tool was performed on the bacterial class level for the two aligned groups (cold vs. warm), generated by merging all taxa from the same seasonal samples (Fig.…”

“…4.5 km 2 and largely consists of farmlands (60%) and forest/marshlands (31%). Grytelandsbekken has previously been studied for spatial variations in the microbial communities of various lotic freshwater ecosystems in different regions of Norway 21 . Based on that study, it was characterised as a rural creek with the highest diversity and abundance of microbial communities.…”

Testing Different Membrane Filters for 16S rRNA Gene-Based Metabarcoding in Karstic Springs

“…Environmental DNA (eDNA) metabarcoding was proposed as viable alternative for the freshwater quality assessment [8] as it quickly and sensitively revealing the taxonomic inventory of eukaryotic [9,10] or prokaryotic communities [11]. Recently, eDNA metabarcoding has proved as useful tool to detect waterborne pathogens in rural surface freshwater impacted by faecal pollution [12] and antibiotic-contaminated groundwater [13]. Surprising little information exists on microbiological quality of groundwater sources that are used as drinking water in rural areas worldwide.…”