Norwegian study on microbial source tracking for water quality control and pollution removal in constructed wetland treating catchment run-off

This study describes the first Norwegian microbial source tracking (MST) approach for water quality control and pollution removal from catchment run-off in a nature-based treatment system (NBTS) with a constructed wetland. The applied MST tools combined microbial analyses and molecular tests to detect and define the source(s) and dominant origin(s) of faecal water contamination. Faecal indicator bacteria Escherichia coli and host-specific Bacteroidales 16 s rRNA gene markers have been employed. The study revealed that the newly developed contribution profiling of faecal origin derived from the Bacteroidales DNA could quantitatively distinguish between human and non-human pollution origins. Further, the outcomes of the MST test have been compared with the results of both physicochemical analyses and tests of pharmaceutical and personal care products (PPCPs). A strong positive correlation was discovered between the human marker and PPCPs. Gabapentin was the most frequently detected compound and it showed the uppermost positive correlation with the human marker. The study demonstrated that the NBTS performs satisfactorily with the removal of E. coli but not PPCPs. Interestingly, the presence of PPCPs in the water samples was not correlated with high concentrations of E. coli. Neither has the latter an apparent correlation with the human marker.

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Constructed wetland technology and its application in water quality control of south lake system

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/794/1/012029 ◽

2020 ◽

Vol 794 ◽

pp. 012029

Author(s):

Li Can ◽

Xu Jing

Keyword(s):

Water Quality ◽

Quality Control ◽

Constructed Wetland ◽

Water Quality Control ◽

Lake System

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Relative Decay of Bacteroidales Microbial Source Tracking Markers and Cultivated Escherichia coli in Freshwater Microcosms

Applied and Environmental Microbiology ◽

10.1128/aem.02636-09 ◽

2010 ◽

Vol 76 (10) ◽

pp. 3255-3262 ◽

Cited By ~ 94

Author(s):

Linda K. Dick ◽

Erin A. Stelzer ◽

Erin E. Bertke ◽

Denise L. Fong ◽

Donald M. Stoeckel

Keyword(s):

Escherichia Coli ◽

Water Quality ◽

Microbial Source Tracking ◽

Decay Rates ◽

Source Tracking ◽

Rrna Gene ◽

Fecal Indicator ◽

Gene Markers ◽

E Coli ◽

Log Reduction

ABSTRACT Fecal indicator bacteria (FIB), commonly used to regulate sanitary water quality, cannot discriminate among sources of contamination. The use of alternative quantitative PCR (qPCR) methods for monitoring fecal contamination or microbial source tracking requires an understanding of relationships with cultivated FIB, as contamination ages under various conditions in the environment. In this study, the decay rates of three Bacteroidales 16S rRNA gene markers (AllBac for general contamination and qHF183 and BacHum for human-associated contamination) were compared with the decay rate of cultivated Escherichia coli in river water microcosms spiked with human wastewater. The following five sets of microcosms were monitored over 11 days: control, artificial sunlight, sediment exposure, reduced temperature, and no autochthonous predation. Decay was characterized by estimation of the time needed to produce a 2-log reduction (t 99). No treatment-associated differences in the decay of the 4 targets were evident except with reduced predation, where E. coli, qHF183, and BacHum markers had lower levels of decay by day 3. However, there were substantial target-associated differences. Decay curves for the AllBac marker indicated a larger persistent population than those of the other targets. Exposure to sunlight, sediment, and reduced predation resulted in more rapid decay of the human-associated markers relative to cultivable E. coli, but there were no differences in t 99 values among the 4 targets under control conditions or at reduced temperatures. Further evaluation of epidemiological relationships will be needed in order to relate the markers directly to health risk. These findings suggest that the tested human-associated markers can complement E. coli as indicators of the human impact on sanitary water quality under the constrained conditions described in this paper.

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Automated Targeted Sampling of Waterborne Pathogens and Microbial Source Tracking Markers Using Near-Real Time Monitoring of Microbiological Water Quality

Water ◽

10.3390/w13152069 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2069

Author(s):

Jean-Baptiste Burnet ◽

Marc Habash ◽

Mounia Hachad ◽

Zeinab Khanafer ◽

Michèle Prévost ◽

...

Keyword(s):

Water Quality ◽

Microbial Source Tracking ◽

Fecal Pollution ◽

Source Tracking ◽

Waterborne Pathogens ◽

Short Term ◽

Sampling Methodology ◽

E Coli ◽

Biochemical Indicator ◽

Microbiological Water Quality

Waterborne pathogens are heterogeneously distributed across various spatiotemporal scales in water resources, and representative sampling is therefore crucial for accurate risk assessment. Since regulatory monitoring of microbiological water quality is usually conducted at fixed time intervals, it can miss short-term fecal contamination episodes and underestimate underlying microbial risks. In the present paper, we developed a new automated sampling methodology based on near real-time measurement of a biochemical indicator of fecal pollution. Online monitoring of β-D-glucuronidase (GLUC) activity was used to trigger an automated sampler during fecal contamination events in a drinking water supply and at an urban beach. Significant increases in protozoan parasites, microbial source tracking markers and E. coli were measured during short-term (<24 h) fecal pollution episodes, emphasizing the intermittent nature of their occurrence in water. Synchronous triggering of the automated sampler with online GLUC activity measurements further revealed a tight association between the biochemical indicator and culturable E. coli. The proposed event sampling methodology is versatile and in addition to the two triggering modes validated here, others can be designed based on specific needs and local settings. In support to regulatory monitoring schemes, it should ultimately help gathering crucial data on waterborne pathogens more efficiently during episodic fecal pollution events.

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