scholarly journals Evaluation of DNA extraction yield from a chlorinated drinking water distribution system

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253799
Author(s):  
Ratna E. Putri ◽  
Lan Hee Kim ◽  
Nadia Farhat ◽  
Mashael Felemban ◽  
Pascal E. Saikaly ◽  
...  
Keyword(s):  
Drinking Water ◽  
Dna Extraction ◽  
Water Distribution ◽  
Cell Concentration ◽  
Tap Water ◽  
Extraction Yield ◽  
Residual Chlorine ◽  
Dna Yield ◽  
Drinking Water Distribution ◽  
Chlorinated Drinking Water

Desalination technology based on Reverse Osmosis (RO) membrane filtration has been resorted to provide high-quality drinking water. RO produced drinking water is characterized by a low bacterial cell concentration. Monitoring microbial quality and ensuring membrane-treated water safety has taken advantage of the rapid development of DNA-based techniques. However, the DNA extraction process from RO-based drinking water samples needs to be evaluated regarding the biomass amount (filtration volume) and residual disinfectant such as chlorine, as it can affect the DNA yield. We assessed the DNA recovery applied in drinking water microbiome studies as a function of (i) different filtration volumes, (ii) presence and absence of residual chlorine, and (iii) the addition of a known Escherichia coli concentration into the (sterile and non-sterile, chlorinated and dechlorinated) tap water prior filtration, and directly onto the (0.2 μm pore size, 47 mm diameter) mixed ester cellulose membrane filters without and after tap water filtration. Our findings demonstrated that the co-occurrence of residual chlorine and low biomass/cell density water samples (RO-treated water with a total cell concentration ranging between 2.47 × 102–1.5 × 103 cells/mL) failed to provide sufficient DNA quantity (below the threshold concentration required for sequencing-based procedures) irrespective of filtration volumes used (4, 20, 40, 60 L) and even after performing dechlorination. After exposure to tap water containing residual chlorine (0.2 mg/L), we observed a significant reduction of E. coli cell concentration and the degradation of its DNA (DNA yield was below detection limit) at a lower disinfectant level compared to what was previously reported, indicating that free-living bacteria and their DNA present in the drinking water are subject to the same conditions. The membrane spiking experiment confirmed no significant impact from any potential inhibitors (e.g. organic/inorganic components) present in the drinking water matrix on DNA extraction yield. We found that very low DNA content is likely to be the norm in chlorinated drinking water that gives hindsight to its limitation in providing robust results for any downstream molecular analyses for microbiome surveys. We advise that measurement of DNA yield is a necessary first step in chlorinated drinking water distribution systems (DWDSs) before conducting any downstream omics analyses such as amplicon sequencing to avoid inaccurate interpretations of results based on very low DNA content. This study expands a substantial source of bias in using DNA-based methods for low biomass samples typical in chlorinated DWDSs. Suggestions are provided for DNA-based research in drinking water with residual disinfectant.

scholarly journals The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System

2018 ◽  
Vol 15 (8) ◽  
pp. 1756 ◽  
Author(s):  
Pirjo-Liisa Rantanen ◽  
Ilkka Mellin ◽  
Minna Keinänen-Toivola ◽  
Merja Ahonen ◽  
Riku Vahala
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Drinking Water Distribution System ◽  
Ammonium Oxidation ◽  
Water Age ◽  
Sampling Campaign ◽  
Drinking Water Distribution

We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data included both the obligatory monitoring and a sampling campaign data from a sampling campaign. Seasonality was evaluated by comparing a nitrite time series to temperature and by calculating the seasonal indices of the nitrite time series. The main drivers of nitrite seasonality were the temperature and the water age. We observed that with low water ages (median: 6.7 h) the highest nitrite exposure occurred during the summer months, and with higher water ages (median: 31 h) during the winter months. With the highest water age (190 h), nitrite concentrations were the lowest. At a low temperature, the high nitrite concentrations in the winter were caused by the decelerated ammonium oxidation. The dominant reaction at low water ages was ammonium oxidation into nitrite and, at high water ages, it was nitrite oxidation into nitrate. These results help to direct monitoring appropriately to gain exact knowledge of nitrite exposure. Also, possible future process changes and additional disinfection measures can be designed appropriately to minimize extra nitrite exposure.

scholarly journals Whole metagenome sequencing of chlorinated drinking water distribution systems

2018 ◽  
Vol 4 (12) ◽  
pp. 2080-2091 ◽  
Author(s):  
Isabel Douterelo ◽  
Carolina Calero-Preciado ◽  
Victor Soria-Carrasco ◽  
Joby B. Boxall
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Quality And Safety ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Chlorinated Drinking Water ◽  
Metagenome Sequencing

This research highlights the potential of whole metagenome sequencing to help protect drinking water quality and safety.

Review / SynthèseA review of drinking-water-associated endotoxin, including potential routes of human exposure

2002 ◽  
Vol 48 (7) ◽  
pp. 567-587 ◽  
Author(s):  
William B Anderson ◽  
Robin M Slawson ◽  
Colin I Mayfield
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Disinfection Byproducts ◽  
Potential Health ◽  
Biofilm Growth ◽  
Disinfection Byproduct ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

In the past decade efforts have been made to reduce the formation of harmful disinfection byproducts during the treatment and distribution of drinking water. This has been accomplished in part by the introduction of processes that involve the deliberate encouragement of indigenous biofilm growth in filters. In a controlled environment, such as a filter, these biofilms remove compounds that would otherwise be available as disinfection byproduct precursors or support uncontrolled biological activity in distribution systems. In the absence of exposure to chlorinated water, most biofilm bacteria are gram negative and have an outer layer that contains endotoxin. To date, outbreaks of waterborne endotoxin-related illness attributable to contamination of water used in hemodialysis procedures have been only infrequently documented, and occurrences linked to ingestion or through dermal abrasions could not be located. However, a less obvious conduit, that of inhalation, has been described in association with aerosolized water droplets. This review summarizes documented drinking-water-associated incidents of endotoxin exposure attributable to hemodialysis and inhalation. Typical endotoxin levels in water and conditions under which substantial quantities can enter drinking water distribution systems are identified. It would appear that endotoxin originating in tap water can be inhaled but at present there is insufficient information available to quantify potential health risks.Key words: endotoxin, lipopolysaccharide, LPS, drinking water.

scholarly journals Estimation of endotoxin inhalation from shower and humidifier exposure reveals potential risk to human health

2007 ◽  
Vol 5 (4) ◽  
pp. 553-572 ◽  
Author(s):  
William B. Anderson ◽  
D. George Dixon ◽  
Colin I. Mayfield
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Cyanobacterial Blooms ◽  
Feed Water ◽  
Adverse Health Effects ◽  
Acute Response ◽  
Drinking Water Distribution ◽  
Treated Drinking Water

This paper investigates potential exposure to endotoxin in drinking water through the inhalation of aerosols generated by showers and humidifiers. Adverse health effects attributable to the inhalation of airborne endotoxin in various occupational settings are summarized, as are controlled laboratory inhalation studies. Data from investigations estimating aerosolization of particulate matter by showers and humidifiers provide a basis for similar analyses with endotoxin, which like minerals in water, is nonvolatile. A theoretical assessment of the inhalation of aerosolized endotoxin showed that while the likelihood of an acute response while showering is minimal, the same is not true for humidifiers. Ultrasonic and impeller (cool mist) humidifiers efficiently produce large numbers of respirable particles. It is predicted that airway inflammation can occur if humidifier reservoirs are filled with tap water, sometimes even at typical drinking-water distribution-system endotoxin concentrations. Higher endotoxin levels occasionally found in drinking water (>1,000 EU/ml) are very likely to induce symptoms such as chills and fever if used as humidifier feed water. While it is unlikely that treated drinking water would contain extremely high endotoxin levels occasionally observed in cyanobacterial blooms (>35,000 EU/ml), the potential for serious acute health consequences exist if used in humidifiers.

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