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Sorensen JPR, Diaw MT, Pouye A, Roffo R, Diongue DML, Faye SC, Gaye CB, Fox BG, Goodall T, Lapworth DJ, MacDonald AM, Read DS, Ciric L, Taylor RG. In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139419. [PMID: 32521357 DOI: 10.1016/j.scitotenv.2020.139419] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
We explore in-situ fluorescence spectroscopy as an instantaneous indicator of total bacterial abundance and faecal contamination in drinking water. Eighty-four samples were collected outside of the recharge season from groundwater-derived water sources in Dakar, Senegal. Samples were analysed for tryptophan-like (TLF) and humic-like (HLF) fluorescence in-situ, total bacterial cells by flow cytometry, and potential indicators of faecal contamination such as thermotolerant coliforms (TTCs), nitrate, and in a subset of 22 samples, dissolved organic carbon (DOC). Significant single-predictor linear regression models demonstrated that total bacterial cells were the most effective predictor of TLF, followed by on-site sanitation density; TTCs were not a significant predictor. An optimum multiple-predictor model of TLF incorporated total bacterial cells, nitrate, nitrite, on-site sanitation density, and sulphate (r2 0.68). HLF was similarly related to the same parameters as TLF, with total bacterial cells being the best correlated (ρs 0.64). In the subset of 22 sources, DOC clustered with TLF, HLF, and total bacterial cells, and a linear regression model demonstrated HLF was the best predictor of DOC (r2 0.84). The intergranular nature of the aquifer, timing of the study, and/or non-uniqueness of the signal to TTCs can explain the significant associations between TLF/HLF and indicators of faecal contamination such as on-site sanitation density and nutrients but not TTCs. The bacterial population that relates to TLF/HLF is likely to be a subsurface community that develops in-situ based on the availability of organic matter originating from faecal sources. In-situ fluorescence spectroscopy instantly indicates a drinking water source is impacted by faecal contamination but it remains unclear how that relates specifically to microbial risk in this setting.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK; Department of Geography, University College London, London WC1E 6BT, UK.
| | - Mor Talla Diaw
- Department of Geology, Université Cheikh Anta Diop, Senegal
| | | | - Raphaëlle Roffo
- Department of Geography, University College London, London WC1E 6BT, UK
| | | | | | - Cheikh B Gaye
- Department of Geology, Université Cheikh Anta Diop, Senegal
| | - Bethany G Fox
- Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Timothy Goodall
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford OX10 8BB, UK
| | - Daniel J Lapworth
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh EH14 4AP, UK
| | - Daniel S Read
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford OX10 8BB, UK
| | - Lena Ciric
- Department of Civil, Environmental & Geomatic Engineering, University College London, London WC1E 6BT, UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, UK
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Eshelman EJ, Malaska MJ, Manatt KS, Doloboff IJ, Wanger G, Willis MC, Abbey WJ, Beegle LW, Priscu JC, Bhartia R. WATSON: In Situ Organic Detection in Subsurface Ice Using Deep-UV Fluorescence Spectroscopy. ASTROBIOLOGY 2019; 19:771-784. [PMID: 30822105 DOI: 10.1089/ast.2018.1925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Terrestrial icy environments have been found to preserve organic material and contain habitable niches for microbial life. The cryosphere of other planetary bodies may therefore also serve as an accessible location to search for signs of life. The Wireline Analysis Tool for the Subsurface Observation of Northern ice sheets (WATSON) is a compact deep-UV fluorescence spectrometer for nondestructive ice borehole analysis and spatial mapping of organics and microbes, intended to address the heterogeneity and low bulk densities of organics and microbial cells in ice. WATSON can be either operated standalone or integrated into a wireline drilling system. We present an overview of the WATSON instrument and results from laboratory experiments intended to determine (i) the sensitivity of WATSON to organic material in a water ice matrix and (ii) the ability to detect organic material under various thicknesses of ice. The results of these experiments show that in bubbled ice the instrument has a depth of penetration of 10 mm and a detection limit of fewer than 300 cells. WATSON incorporates a scanning system that can map the distribution of organics and microbes over a 75 by 25 mm area. WATSON demonstrates a sensitive fluorescence mapping technique for organic and microbial detection in icy environments including terrestrial glaciers and ice sheets, and planetary surfaces including Europa, Enceladus, or the martian polar caps.
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Affiliation(s)
- Evan J Eshelman
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Michael J Malaska
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Kenneth S Manatt
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Ivria J Doloboff
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Greg Wanger
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
- 2 University of Southern California, Los Angeles, California
| | - Madelyne C Willis
- 3 Montana State University, Department of Land Resources and Environmental Science, Bozeman, Montana
| | - William J Abbey
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Luther W Beegle
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - John C Priscu
- 3 Montana State University, Department of Land Resources and Environmental Science, Bozeman, Montana
| | - Rohit Bhartia
- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Sorensen JPR, Baker A, Cumberland SA, Lapworth DJ, MacDonald AM, Pedley S, Taylor RG, Ward JST. Real-time detection of faecally contaminated drinking water with tryptophan-like fluorescence: defining threshold values. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1250-1257. [PMID: 29890592 DOI: 10.1016/j.scitotenv.2017.11.162] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/14/2017] [Accepted: 11/15/2017] [Indexed: 06/08/2023]
Abstract
We assess the use of fluorescent dissolved organic matter at excitation-emission wavelengths of 280nm and 360nm, termed tryptophan-like fluorescence (TLF), as an indicator of faecally contaminated drinking water. A significant logistic regression model was developed using TLF as a predictor of thermotolerant coliforms (TTCs) using data from groundwater- and surface water-derived drinking water sources in India, Malawi, South Africa and Zambia. A TLF threshold of 1.3ppb dissolved tryptophan was selected to classify TTC contamination. Validation of the TLF threshold indicated a false-negative error rate of 15% and a false-positive error rate of 18%. The threshold was unsuccessful at classifying contaminated sources containing <10 TTC cfu per 100mL, which we consider the current limit of detection. If only sources above this limit were classified, the false-negative error rate was very low at 4%. TLF intensity was very strongly correlated with TTC concentration (ρs=0.80). A higher threshold of 6.9ppb dissolved tryptophan is proposed to indicate heavily contaminated sources (≥100 TTC cfu per 100mL). Current commercially available fluorimeters are easy-to-use, suitable for use online and in remote environments, require neither reagents nor consumables, and crucially provide an instantaneous reading. TLF measurements are not appreciably impaired by common intereferents, such as pH, turbidity and temperature, within typical natural ranges. The technology is a viable option for the real-time screening of faecally contaminated drinking water globally.
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Affiliation(s)
| | - Andy Baker
- Connected Waters Initiative Research Centre, UNSW Australia, Sydney, New South Wales 2052, Australia
| | | | - Dan J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | | | - Steve Pedley
- Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, UK
| | - Jade S T Ward
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK; Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
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Non-destructive mobile monitoring of microbial contaminations on meat surfaces using porphyrin fluorescence intensities. Meat Sci 2016; 115:1-8. [DOI: 10.1016/j.meatsci.2015.12.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 12/28/2015] [Accepted: 12/29/2015] [Indexed: 11/19/2022]
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Hill SC, Pan YL, Williamson C, Santarpia JL, Hill HH. Fluorescence of bioaerosols: mathematical model including primary fluorescing and absorbing molecules in bacteria. OPTICS EXPRESS 2013; 21:22285-313. [PMID: 24104120 DOI: 10.1364/oe.21.022285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This paper describes a mathematical model of fluorescent biological particles composed of bacteria, viruses, or proteins. The fluorescent and/or light absorbing molecules included in the model are amino acids (tryptophan, etc.); nucleic acids (DNA, RNA, etc.); coenzymes (nicotinamide adenine dinucleotides, flavins, and vitamins B₆ and K and variants of these); and dipicolinates. The concentrations, absorptivities, and fluorescence quantum yields are estimated from the literature, often with large uncertainties. The bioparticles in the model are spherical and homogeneous. Calculated fluorescence cross sections for particles excited at 266, 280, and 355 nm are compared with measured values from the literature for several bacteria, bacterial spores and albumins. The calculated 266- and 280-nm excited fluorescence is within a factor of 3.2 of the measurements for the vegetative cells and proteins, but overestimates the fluorescence of spores by a factor of 10 or more. This is the first reported modeling of the fluorescence of bioaerosols in which the primary fluorophores and absorbing molecules are included.
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Kim J, Kim EG, Bae S, Kwon S, Chun H. Potentiometric Multichannel Cytometer Microchip for High-throughput Microdispersion Analysis. Anal Chem 2012. [DOI: 10.1021/ac302905x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Junhoi Kim
- Department of Electrical
Engineering and Computer Science, Seoul National University, Seoul 151-744, Korea
- Inter-university Semiconductor
Research Center, Seoul National University, Seoul 151-742, Korea
| | - Eun-Geun Kim
- Department of Electrical
Engineering and Computer Science, Seoul National University, Seoul 151-744, Korea
- Quantamatrix Inc., Seoul 151-742, Korea
| | - Sangwook Bae
- Interdisciplinary
Program for Bioengineering, Seoul National University, Seoul 151-742, Korea
| | - Sunghoon Kwon
- Department of Electrical
Engineering and Computer Science, Seoul National University, Seoul 151-744, Korea
- Inter-university Semiconductor
Research Center, Seoul National University, Seoul 151-742, Korea
- Quantamatrix Inc., Seoul 151-742, Korea
- Center for Nanoparticle Research, Institute
for Basic Science, Seoul National University, Seoul 151-742, Korea
| | - Honggu Chun
- Department of Biomedical
Engineering, Korea University, Seoul 136-703, Korea
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Farsund Ø, Rustad G, Skogan G. Standoff detection of biological agents using laser induced fluorescence-a comparison of 294 nm and 355 nm excitation wavelengths. BIOMEDICAL OPTICS EXPRESS 2012; 3:2964-2975. [PMID: 23162732 PMCID: PMC3493216 DOI: 10.1364/boe.3.002964] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/15/2012] [Accepted: 10/16/2012] [Indexed: 05/29/2023]
Abstract
Standoff detection measuring the fluorescence spectra of seven different biological agents excited by 294 nm as well as 355 nm wavelength laser pulses has been undertaken. The biological warfare agent simulants were released in a semi-closed aerosol chamber at 210 m standoff distance and excited by light at either of the two wavelengths using the same instrument. Significant differences in several of the agents' fluorescence response were seen at the two wavelengths. The anthrax simulants' fluorescence responses were almost an order of magnitude stronger at the shorter wavelength excitation. However, most importantly, the fluorescence spectra were significantly more dissimilar at 294 nm than at 355 nm excitation with ~7 nm spectral resolution. This indicates that classification of the substances should be possible with a lower error rate for standoff detection using 294 nm rather than 355 nm excitation wavelength, or even better, utilizing both.
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Hudson N, Baker A, Ward D, Reynolds DM, Brunsdon C, Carliell-Marquet C, Browning S. Can fluorescence spectrometry be used as a surrogate for the Biochemical Oxygen Demand (BOD) test in water quality assessment? An example from South West England. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 391:149-158. [PMID: 18054993 DOI: 10.1016/j.scitotenv.2007.10.054] [Citation(s) in RCA: 197] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 10/23/2007] [Accepted: 10/28/2007] [Indexed: 05/25/2023]
Abstract
The fluorescence intensities of tryptophan-like, tyrosine-like and humic-like materials were determined using excitation-emission-matrices (EEMs) for a wide range of samples including natural surface waters, sewage and industrial effluents and waters that have experienced known pollution events from the South West of England (n=469). Fluorescence intensities reported in arbitrary fluorescence units (AFU) were correlated with standard five day Biochemical Oxygen Demand (BOD(5)) values which were used as an indicator of the amount of biodegradable organic material present. Tryptophan-like fluorescence, which has been found to relate to the activity of the biological community, showed the strongest correlation with BOD(5). Fluorescence analysis of the tryptophan-like peak (excitation/emission wavelength region 275/340 nm) is found to provide an accurate indication of the presence, and relative proportions of bioavailable organic material present (natural or anthropogenic). It therefore provides an insight relating to its oxygen depleting potential. Thus fluorescence spectroscopy is recommended as a portable or laboratory tool for the determination of the presence of biodegradable organic matter with intrinsic oxidising potential in natural waters. The novel application of Geographically Weighted Regression (GWR) to the data illustrates that strong local relationships exist between the two parameters and that site specific character may be a strong factor in the strength of the tryptophan-like fluorescence/BOD(5) relationship.
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Affiliation(s)
- Naomi Hudson
- Department of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
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Jhala E, Galilee C, Reinisch L. Principal component analysis of fluorescence changes upon growth conditions and washing of Pseudomonas aeruginosa. APPLIED OPTICS 2007; 46:5522-8. [PMID: 17676169 DOI: 10.1364/ao.46.005522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We have measured the autofluorescence from suspensions of Pseudomonas aeruginosa in the growth medium and after one, two, and three washes. The bacterium was grown in two different media, nutrient broth and King's B broth. The bacterium was harvested after 12, 24, and 48 h of growth. The fluorescence was measured with excitation every 10 nm from 200 nm to 600 nm. The fluorescence profiles were analyzed using principal component analysis. We found that most of the information is in the first three principal components. Stark differences in the value of the first principal component were noted between the samples in broth and those with one, two, or three washings. The second and third principal components noted differences between the samples washed once and those washed two or three times. There was no significant difference between samples washed two and three times. There are small differences noted between the samples grown in the two different broths, and no differences were noted among the samples harvested at different times.
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Affiliation(s)
- Ekta Jhala
- Department of Physics and Astronomy, University of Canterbury, Christchurch, New Zealand
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Eversole JD, Cary WK, Scotto CS, Pierson R, Spence M, Campillo AJ. Continuous bioaerosol monitoring using UV excitation fluorescence: Outdoor test results. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/fact.1022] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pan YL, Holler S, Chang RK, Hill SC, Pinnick RG, Niles S, Bottiger JR. Single-shot fluorescence spectra of individual micrometer-sized bioaerosols illuminated by a 351- or a 266-nm ultraviolet laser. OPTICS LETTERS 1999; 24:116-118. [PMID: 18071426 DOI: 10.1364/ol.24.000116] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Reproducible fluorescence spectra of individual 2- to 5-microm -diameter biological aerosol particles excited with a single shot from a Q -switched laser (266 or 351 nm) have been obtained with highly improved signal-to-noise ratios. Critical to the advance are crossed diode-laser trigger beams, which precisely define the sample volume, and a reflecting objective, which minimizes chromatic aberration and has a large N.A. for collecting fluorescence. Several allergens (red oak, meadow oat pollen, paper mulberry pollen, and puffball spores) have different fluorescence spectra. Bacillus subtilis fluorescence spectrum deteriorates at high 266-nm incident intensity. Dry riboflavin particles illuminated with a 351-nm light exhibit a new 420-nm fluorescence peak that grows nonlinearly with laser pulse energy.
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Hill SC, Pinnick RG, Niles S, Pan YL, Holler S, Chang RK, Bottiger J, Chen BT, Orr CS, Feather G. Real-time measurement of fluorescence spectra from single airborne biological particles. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1520-6521(1999)3:4/5<221::aid-fact2>3.0.co;2-7] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Eversole JD, Hardgrove JJ, Cary WK, Choulas DP, Seaver M. Continuous, rapid biological aerosol detection with the use of UV fluorescence: Outdoor test results. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1520-6521(1999)3:4/5<249::aid-fact4>3.0.co;2-o] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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