Skip to main content

Research Repository

Advanced Search

In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon

Sorensen, James P.R.; Diaw, Mor Talla; Pouye, Abdoulaye; Roffo, Rapha�lle; Diongue, Djim M.L.; Faye, Seynabou C.; Gaye, Cheikh B.; Fox, Bethany G.; Goodall, Timothy; Lapworth, Daniel J.; MacDonald, Alan M.; Read, Daniel S.; Ciric, Lena; Taylor, Richard G.

In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon Thumbnail


Authors

James P.R. Sorensen

Mor Talla Diaw

Abdoulaye Pouye

Rapha�lle Roffo

Djim M.L. Diongue

Seynabou C. Faye

Cheikh B. Gaye

Bethany Fox Bethany.Fox@uwe.ac.uk
Occasional Associate Lecturer - HAS - DAS

Timothy Goodall

Daniel J. Lapworth

Alan M. MacDonald

Daniel S. Read

Lena Ciric

Richard G. Taylor



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.

Journal Article Type Article
Acceptance Date May 11, 2020
Online Publication Date May 19, 2020
Publication Date Oct 10, 2020
Deposit Date Jun 1, 2020
Publicly Available Date Jun 2, 2020
Journal Science of the Total Environment
Print ISSN 0048-9697
Electronic ISSN 1879-1026
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 738
Article Number 139419
DOI https://doi.org/10.1016/j.scitotenv.2020.139419
Keywords Environmental Engineering; Waste Management and Disposal; Pollution; Environmental Chemistry
Public URL https://uwe-repository.worktribe.com/output/6003613
Publisher URL https://www.sciencedirect.com/science/article/pii/S0048969720329363?via%3Dihub#!

Files

In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon (1.8 Mb)
PDF

Licence
http://creativecommons.org/licenses/by/4.0/

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/

Copyright Statement
https://doi.org/10.1016/j.scitotenv.2020.139419
0048-9697/© 2020 United Kingdom Research and Innovation, as represented by its component body, the British Geological Survey. Published by Elsevier B.V. This is an open access article
under the CC BY license (http://creativecommons.org/licenses/by/4.0/).





You might also like



Downloadable Citations