Flow-cytometric total bacterial cell counts as a descriptive microbiological parameter for drinking water treatment processes

Hammes, Frederik; Berney, Michael; Wang, Yingying; Vital, Marius; Köster, Oliver; Egli, Thomas

doi:10.1016/j.watres.2007.07.009

Cited by 524 publications

(410 citation statements)

References 29 publications

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“…As of today there are no literature of this type of data. Few sources give similar values for the number of microorganisms as obtained in the studies presented [4,5]. The most reliable results quantities of the microorganism obtained by flow cytometry was obtained for surface water and rainwater.…”

supporting

confidence: 61%

“…By far higher numbers of bacteria were obtained on agar "R" in the case of both mesophylic and psychrophylic in all tested samples of the water. ' R ' agar is a culture medium containing substances that allow the growth of microorganisms of the heterotrophic species of larger nutrient requirements [4]. The results of the quantity of the microorganism obtained by flow cytometry in different types of water surveyed strongly deviate from the New method for evaluation of the microbiological quality...…”

Section: Test Results and Their Discussionmentioning

confidence: 99%

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Newmethod for evaluation of the microbiological quality of water

2015

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Determination of the microbiological quality of water is one of the central tasks of environmental engineering. Reliability and accuracy of the results depends largely on the sampling system and the methodology carried signs. Typically, they are used traditional indirect methods, breeding: plate method or test tube fermentation. In the methods, seed stocks, it is assumed that each individual cell of bacteria transferred to a solid substrate colony grows. Thus, in fact, the result of the study determines the number of units capable of forming colonies, which is not equivalent to the amount of the living. Even larger errors are subject to the results of the analysis of test tube fermentation, which can only be the most probable number of bacteria in a given volume. It is therefore only estimating the number of microorganisms. Moreover, indirect methods are extremely time consuming (about 1 -7 days of). Flow cytometry is an analytical technique that allows for the rapid measurement of scattered light and fluorescence signals emitted by cells exposed respectively. Allows for a qualitative and quantitative assessment of the physical and biological properties of the cells in a short time. The article presents the results of research on the amount of bacterial cells in different water: surface, groundwater, rainwater and tap water using flow cytometry and compare this results obtained with traditional methods of reference. The microbial results in all the tested waters by flow cytometry are much higher than the amount of the reported conventional methods.

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supporting

confidence: 61%

Section: Test Results and Their Discussionmentioning

confidence: 99%

Newmethod for evaluation of the microbiological quality of water

2015

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“…Therefore, only ATP levels after 5, 10, 20 and 40 min were considered for calculating the ATP production rate, or ATP-generation potential, and those data were used for the calculation of a linear regression curve (DATP/Dt). It was not necessary to distinguish between 'free' and 'cellular' ATP as fractions of 'total' ATP (Hammes et al, 2008) since initial experiments showed that total ATP corresponded to intracellular ATP for our experimental settings and free ATP was found only as a negligible fraction (,5 %). In all experiments no changes in OD 546 were observed.…”

Section: Methodsmentioning

confidence: 99%

The respiratory chain is the cell's Achilles' heel during UVA inactivation in Escherichia coli

et al. 2010

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Solar disinfection (SODIS) is used as an effective and inexpensive tool to improve the microbiological quality of drinking water in developing countries where no other means are available. Solar UVA light is the agent that inactivates bacteria during the treatment. Damage to bacterial membranes plays a crucial role in the inactivation process. This study showed that even slightly irradiated cells (after less than 1 h of simulated sunlight) were strongly affected in their ability to maintain essential parts of their energy metabolism, in particular of the respiratory chain (activities of NADH oxidase, succinate oxidase and lactate oxidase were measured). The cells' potential to generate ATP was also strongly inhibited. Many essential enzymes of carbon metabolism (glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase and malate dehydrogenase) and defence against oxidative stress (catalases and glutathione-disulfide reductase) were reduced in their activity during SODIS. The work suggests that damage to membrane enzymes is a likely cause of membrane dysfunction (loss of membrane potential and increased membrane permeability) during UVA irradiation. In this study, the first targets on the way to cell death were found to be the respiratory chain and F 1 F 0 ATPase.

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“…For example, FC was reported to be four times faster and more accurate (<5% standard deviation compared to >10% for EpiM) than EpiM ). Moreover, it is possible to directly count by FC when the concentrations of bacteria are as low as 10 3 -10 4 cells/mL, whereas EpiM requires sample concentration (Wang et al 2007;Hammes et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Dynamics of bacterial abundance and the related environmental factors in large shallow eutrophic Lake Taihu

Gong

Tang

Shao

et al. 2016

Journal of Freshwater Ecology

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In aquatic ecosystems, estimation of bacterial abundance (BA) is intimately connected to the development of an understanding of the role of bacteria in microbial food webs. Flow cytometry (FC) can rapidly calculate BA, but to date mostly has been applied in marine waters with limited use in shallow eutrophic lakes because of the abundant organic and inorganic matter. To seek the best compromise between precision and the clarity for the differentiation of bacteria from other submicron-sized particles and colloids in eutrophic lakes, we optimized FC instrument settings, fixatives and storage conditions, ultrasonic pre-treatment and staining protocols. Then, BA in Lake Taihu was investigated by the optimized FC procedures. Regression analysis showed good correspondence (R 2 D 0.72, p < 0.001, n D 128) of BA counted by FC and epifluorescence microscopy. The developed protocol was successfully applied to monitor the dynamics of BA in the large shallow eutrophic Lake Taihu. A distinct spatio-temporal shift of BA in Lake Taihu was observed. The shift was found to be mainly related to dissolved organic carbon, total suspended solids, water temperature and chlorophyll-a. Our results highlight the effect of sediment re-suspension and algal biomass on BA in eutrophic shallow lakes.

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Flow-cytometric total bacterial cell counts as a descriptive microbiological parameter for drinking water treatment processes

Cited by 524 publications

References 29 publications

Newmethod for evaluation of the microbiological quality of water

Newmethod for evaluation of the microbiological quality of water

The respiratory chain is the cell's Achilles' heel during UVA inactivation in Escherichia coli

Dynamics of bacterial abundance and the related environmental factors in large shallow eutrophic Lake Taihu

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