Microbial ecology of biofilms from drinking water distribution systems: Importance for monitoring and public health

CRUZ, MERCEDES CECILIA

Buenos Aires

Workshop; Humboldt Colloquium Shaping the Future of German-Argentinian Scientific Cooperation The Role of Curiosity-Driven Research; 2018

Microbial ecology of biofilms from drinking water distribution systems (DWDS): Importance for monitoring and public health. Drinking water is not sterile and has many microorganisms that resisted the disinfection process. These bacteria could form biofilms in the inner wall of pipes, providing a refuge for pathogens. The biofilm formation is influenced by diverse factors like water chemistry composition, type of disinfectant used, temperature, and engineering related issues such as infrastructure, pipe age, material, flow rate, among others. Furthermore, disinfectants and the low nutrient load make DWDS unique environments, with biofilms behaving differently than in the planktonic phase. In Argentina and in the province of Salta, in particular, little is known about the drinking water microbiome. More than 95% of the population is supplied with drinking water by mean of an extended network, and many locations with very old pipelines, are at high risk of waterborne diseases. For surveillance, there is a lack of appropriate indicator microorganisms that represent the actual microbial community or alert of processes like biocorrosion.The overall objective is to start an innovative and integral research line that involves cutting-edge knowledge of microbiology, metagenomics, and engineering to holistically understand the drinking water microbiome from source to tap, and the risk associated to its exposure. This strategy will allow us to assess the importance of biofilms as a reservoir of pathogens in the drinking water microbiome, to provide safe water and thus, reducing waterborne diseases transmission. The specific aims are: 1) to characterise the microbial community in biofilm and water phases, 2) to identify the effect of seasonality and disinfectant (hypochlorite) concentration on the community structure to improve disinfection strategies, 3) based on the whole microbial community, propose new biomarkers (indicators) for fast monitoring and to guarantee water stability, 4) to compare traditional vs molecular techniques for microbial quality, and 5) to isolate microorganisms to assess if their disinfectant tolerance is related to the presence of antibiotic resistance genes. Advanced multivariate statistical analyses will be used for hypothesis testing and correlations of engineering parameters with water quality variables. Bioinformatics analysis from high throughput sequencing will be used to understand how diverse are the microbial communities across the DWDS and built systems. To know who are the biological players in the DWDS, what is the main function they perform, and how they relate to each other, will help to comprehend the microbial interactions with the built environment.To achieve those aims actual scale surveys and a pilot plant loop is planned to be constructed.