Protozoan bacterivory and Escherichia coli survival in drinking water distribution systems.
The development of bacterial communities in drinking water distribution systems leads to a food chain which supports the growth of macroorganisms incompatible with water quality requirements and esthetics.
Nevertheless, very few studies have examined the microbial communities in drinking water distribution systems and their trophic relationships.
This study was done to quantify the microbial communities (especially bacteria and protozoa) and obtain direct and indirect proof of protozoan feeding on bacteria in two distribution networks, one of GAC water (i.e., water filtered on granular activated carbon) and the other of nanofiltered water.
The nanofiltered water-supplied network contained no organisms larger than bacteria, either in the water phase (on average, 5 x 107 bacterial cells liter-) or in the biofilm (on average, 7 x 106 bacterial cells cm-2).
No protozoa were detected in the whole nanofiltered water-supplied network (water plus biofilm).
In contrast, the GAC water-supplied network contained bacteria (on average, 3 x 108 cells liter-1 in water and 4 x 107 cells cm-2 in biofilm) and protozoa (on average, 105 cells liter-in water and 103 cells cm-2 in biofilm).
The water contained mostly flagellates (93%), ciliates (1.8%), thecamoebae (1.6%), and naked amoebae (1.1%). The biofilm had only ciliates (52%) and thecamoebae (48%). (...)
Mots-clés Pascal : Système distribution, Eau potable, Biofilm, Protozoa, Bactérivore, Escherichia coli, Enterobacteriaceae, Bactérie, Survie, Dénombrement, Relation trophique, Qualité eau, Communauté microbienne
Mots-clés Pascal anglais : Distribution system, Drinking water, Biofilm, Protozoa, Bacterivorous, Escherichia coli, Enterobacteriaceae, Bacteria, Survival, Enumeration(counting), Trophic relation, Water quality, Microbial community
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0128817
Code Inist : 002A14C02. Création : 22/06/1998.