scholarly journals Biofilm formation potential and chlorine resistance of typical bacteria isolated from drinking water distribution systems

RSC Advances ◽  
2020 ◽  
Vol 10 (52) ◽  
pp. 31295-31304 ◽  
Author(s):  
Zebing Zhu ◽  
Lili Shan ◽  
Fengping Hu ◽  
Zehua Li ◽  
Dan Zhong ◽  
...  
Keyword(s):  
Drinking Water ◽  
Microbial Communities ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Formation Potential ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Safety Of Drinking Water

Biofilms are the main carrier of microbial communities throughout drinking water distribution systems (DWDSs), and strongly affect the safety of drinking water.

Kinetic aspects of biofilm formation on surfaces exposed to drinking water

1995 ◽  
Vol 32 (8) ◽  
pp. 61-65 ◽  
Author(s):  
D. van der Kooij ◽  
H. S. Vrouwenvelder ◽  
H. R. Veenendaal
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Formation Rate ◽  
Water Distribution Systems ◽  
Acetate Concentration ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
The Relationship

Biofilm formation in drinking water distribution systems should be limited to prevent the multiplication of undesirable bacteria and other organisms. Certain types of drinking water with an AOC concentration below 10 μg of acetate-C eq/l can support the growth of Aeromonas. Therefore, the effect of acetate at a concentration of 10 μg of C/l on the biofilm formation rate (BFR) of drinking water with a low AOC concentration (3.2 μg C/l) was determined. Drinking water without acetate had a BFR of 3.9 pg ATP/cm2.day, whereas a BFR value of 362 pg ATP/cm2.day was found with acetate added. These data indicate that a low acetate concentration strongly affects biofilm formation, and that only a small fraction of AOC is available for biofilm formation. Aeromonads did not multiply in the biofilm despite their ability to grow at a concentration of 10 μg of acetate-C/l. Further investigations are needed to elucidate the relationship between substrate concentration and biofilm formation in drinking water distribution systems and the growth of undesirable bacteria in these biofilms.

scholarly journals Protozoan Bacterivory and Escherichia coli Survival in Drinking Water Distribution Systems

1998 ◽  
Vol 64 (1) ◽  
pp. 197-202 ◽  
Author(s):  
I. Sibille ◽  
T. Sime-Ngando ◽  
L. Mathieu ◽  
J. C. Block
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Microbial Communities ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Trophic Relationships ◽  
Bacterial Cells ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

ABSTRACT 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 × 107bacterial cells liter−1) or in the biofilm (on average, 7 × 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 × 108 cells liter−1 in water and 4 × 107 cells cm−2 in biofilm) and protozoa (on average, 105cells liter−1 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%). Only the ciliates at the solid-liquid interface of the GAC water-supplied network had a measurable grazing activity in laboratory test (estimated at 2 bacteria per ciliate per h). Protozoan ingestion of bacteria was indirectly shown by adding Escherichia colito the experimental distribution systems. Unexpectedly, E. coli was lost from the GAC water-supplied network more rapidly than from the nanofiltered water-supplied network, perhaps because of the grazing activity of protozoa in GAC water but not in nanofiltered water. Thus, the GAC water-supplied network contained a functional ecosystem with well-established and structured microbial communities, while the nanofiltered water-supplied system did not. The presence of protozoa in drinking water distribution systems must not be neglected because these populations may regulate the autochthonous and allochthonous bacterial populations.

scholarly journals Linking flow velocity-regulated EPS production with early-stage biofilm formation in drinking water distribution systems

2020 ◽  
Vol 20 (4) ◽  
pp. 1253-1263
Author(s):  
Yanyan Liu ◽  
Rongrong Shan ◽  
Guowei Chen ◽  
Li Liu
Keyword(s):  
Drinking Water ◽  
Flow Velocity ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Extracellular Polymeric Substances ◽  
Early Stage ◽  
Water Distribution Systems ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Abstract Hydrodynamics impacts interactions between microbes and their micro-habitats in aqueous systems, thus the study of hydrodynamics is key to understanding the formation and dynamics of biofilms. Yet mechanisms of how microbial responses to hydrodynamics regulate biofilm formation in drinking water distribution systems (DWDS) are underappreciated. Here, we investigated the linkage between early-stage biofilm formation and flow velocity fluctuations in a model DWDS. Results showed that an intermediate velocity (1.0 m/s) enhanced biofilm formation, with the highest biofilm/total cells ratio of 96.91% ± 2.26%. Moreover, the intermediate velocity promoted extracellular polymeric substances (EPS) release, accompanied with lowered zeta potential and elevated hydrophobicity of suspended cells, which could be responsible for surface aggregation. Shifts in biofilm community were observed along with hydrodynamics fluctuations. Intermediate velocity (1.0 m/s) stimulated the dominance of Proteobacteria (78.16%) along with the genus predominance of Pseudomonas, known to secrete large amounts of EPS favoring biofilm formation. Overall, this study provides new understanding of biofilm formation responding to hydrodynamic fluctuations in DWDS.

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