Quantification of bacteria in water using PLS analysis of emission spectra of fluorescence and excitation-emission matrices

Nakar, Amir; Schmilovitch, Z.; Vaizel-Ohayon, Dalit; Kroupitski, Yulia; Borisover, Mikhail; Sela, Shlomo

doi:10.1016/j.watres.2019.115197

Cited by 40 publications

(19 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, it is supportive of TLF being associated with total microbial biomass 34 and activity, as opposed to purely TTCs, such as E. coli. Previous work has shown a vast assortment of microbes exhibit TLF [57][58][59] , including ubiquitous species in the environment 23,60,61 .…”

Section: Discussionmentioning

confidence: 99%

Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators

Sorensen

Carr

Nayebare

et al. 2020

Sci Rep

View full text Add to dashboard Cite

Fluorescent natural organic matter at tryptophan-like (TLF) and humic-like fluorescence (HLF) peaks is associated with the presence and enumeration of faecal indicator bacteria in groundwater. We hypothesise, however, that it is predominantly extracellular material that fluoresces at these wavelengths, not bacterial cells. We quantified total (unfiltered) and extracellular (filtered at < 0.22 µm) TLF and HLF in 140 groundwater sources across a range of urban population densities in Kenya, Malawi, Senegal, and Uganda. Where changes in fluorescence occurred following filtration they were correlated with potential controlling variables. A significant reduction in TLF following filtration (ΔTLF) was observed across the entire dataset, although the majority of the signal remained and thus considered extracellular (median 96.9%). ΔTLF was only significant in more urbanised study areas where TLF was greatest. Beneath Dakar, Senegal, ΔTLF was significantly correlated to total bacterial cells (ρs 0.51). No significant change in HLF following filtration across all data indicates these fluorophores are extracellular. Our results suggest that TLF and HLF are more mobile than faecal indicator bacteria and larger pathogens in groundwater, as the predominantly extracellular fluorophores are less prone to straining. Consequently, TLF/HLF are more precautionary indicators of microbial risks than faecal indicator bacteria in groundwater-derived drinking water.

show abstract

Section: Discussionmentioning

confidence: 99%

Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators

Sorensen

Carr

Nayebare

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…While the reliability test is based on the composite reliability test (Ghozali, 2006;Hair et al, 2016). While testing the structural model with PLS by Nakar et al (2019) performed with R-square and path coefficients with the following criteria (Table 2):…”

Section: Methodsmentioning

confidence: 99%

The effect of humanitarian logistics service quality to customer loyalty using Kansei engineering: Evidence from Indonesian logistics service providers

Masudin

Safitri

Restuputri

et al. 2020

Cogent Business & Management

View full text Add to dashboard Cite

customer satisfaction, loyalty, and trust as a moderating variable. Eighty respondents completed the formal survey. The pilot test and the structured questionnaire were analyzed using the SPSS 21 and Smart-PLS 2.0 to evaluate the relationship between the variables. The results of this study were accepted three out of eight hypotheses. The personnel service quality has a significant impact on customer satisfaction, customer satisfaction has a significant effect on customer loyalty, and technical service quality has a considerable impact on customer loyalty. The use of Kansei engineering for humanitarian logistics service in this study would provide a different perspective in terms of capturing the voice of customers' perception of relief logistics service quality

show abstract

“…By analyzing the fluorescence spectra of different bacteria, we concluded that the fluorescence peaks at 300 nm, 335–350 nm, and 515.9 nm of the bacterial solutions were due to the fluorescence emission of tyrosine, tryptophan, and flavin [ 2 , 3 , 4 , 5 , 6 , 11 , 12 ] (see Table 1 ), respectively. The main fluorescence emission peaks at 335–350 nm in the four bacterial solutions are dominated by tryptophan in living bacterial cells [ 13 ].…”

Section: Resultsmentioning

confidence: 99%

“…Tryptophan-like fluorescence (TLF, also known as the T-peak) is widely used not only as a tool for monitoring local structural and dynamic changes in proteins, but also as a viable means of inexpensive and rapid detection of bacterial contamination in water. Some research results have shown that the T-peak near 350 nm highly correlates with several aqueous physicochemical properties [ 4 ], and the detection of microorganisms in water using fluorescence spectroscopy has been widely carried out with considerable potential [ 5 ]. Simões et al [ 6 ] developed a low-cost optofluidic sensor to detect pathogens in drinking water by detecting tryptophan in bacteria with an accuracy of up to 10 3 CFU/mL.…”

Section: Introductionmentioning

confidence: 99%

Rapid Detection of Three Common Bacteria Based on Fluorescence Spectroscopy

Yang

Yin

2022

Sensors

View full text Add to dashboard Cite

As an important part of environmental water quality monitoring, efficient bacterial detection has attracted widespread attention. Among them, LIF (laser-induced fluorescence) technology has the characteristics of high efficiency and sensitivity for bacterial detection. To simplify the experimental process of bacterial detection, fluorescence emission spectra of E. coli (Escherichia coli) and its deactivated controls, K. pneumoniae (Klebsiella pneumoniae) and S. aureus (Staphylococcus aureus), were analyzed with fluorescence excitation by a 266 nm laser. By analyzing the results, it was found that the dominant fluorescence peaks of bacterial solutions at 335~350 nm were contributed by tryptophan, and the subfluorescence peaks at 515.9 nm were contributed by flavin; besides, K. pneumoniae and S. aureus had their own fluoresces characteristics, such as tyrosine contributing to sub-fluorescence peaks at 300 nm. The three species of bacteria can be differentiated with whole fluorescence spectrum by statistically analysis (p < 0.05), for various concentrations of aromatic amino acids and flavin in different bacteria. The experimental results also proved that the inactivation operation did not alter the spectral properties of E. coli. The indexes of fluorescence intensity and FIR (fluorescence intensity ratio, I335~350/I515.9) can be used to retrieve the bacteria concentration as well as for bacteria differentiation using the index of slopes. The detection limit of bacteria is less than ~105 cell/mL using laser induced fluorescence methods in the paper. The study demonstrated the rapid detection capability of the LIF bacterial detection system and its great potential for rapid quantitative analysis of bacteria. This may bring new insight into the detection of common bacteria in water in situ.

show abstract

Quantification of bacteria in water using PLS analysis of emission spectra of fluorescence and excitation-emission matrices

Cited by 40 publications

References 39 publications

Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators

Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators

The effect of humanitarian logistics service quality to customer loyalty using Kansei engineering: Evidence from Indonesian logistics service providers

Rapid Detection of Three Common Bacteria Based on Fluorescence Spectroscopy

Contact Info

Product

Resources

About