Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorRobson, Aidan Francis Frederick-
dc.descriptionEngD Thesisen_US
dc.description.abstractThis thesis evaluates the suitability of two emerging microbial source tracking (MST) techniques, host-associated E. coli biomarkers and community-based MST. Previous human-associated E.coli markers (H8, H12, H14, H24) were evaluated for the first time in the UK; the sensitivity of H8 (10%) was lower than previously reported (50% (Gomi et al., 2014)) and if analysed through regulatory culture-based approaches alone, would have resulted in a high false negative rate (90%). In light of this, the Hu100 marker, with the highest abundance (2.64 x 106 gene copies/100 mL) across 14 wastewater treatment plants, was developed through interrogation of 263 E.coli genomes. The abundance of Hu100 was not significantly different to other markers, which, could be due to the large variability in the proportion of E.coli containing biomarkers. Due to this variation, it is recommend that the total marker abundance is used to compare different sites. Community-based MST uses high-throughput sequencing to compare bacterial communities of environmental samples, such as sea water, faecal taxon libraries (FTLs) which contain bacterial communities from known sources. Simulated microbial communities were used to evaluate how the composition of FTLs affected the accuracy and sensitivity of community-based MST. The inclusion of local samples appears to be more important than the size of the FTL to the accuracy of community-based MST. Furthermore, the inclusion of a river water sample as a ‘background sample’, improved method sensitivity from a 5% mixture of the sewage bacterial community in river waste to a 2% contribution of sewage. Two catchment studies highlighted the ubiquity of urban diffuse pollution, largely from septic tanks and misconnections, in rural and semi-rural catchments. Community-based MST showed a good correlation with human-associated markers and (rs >0.467, p <4.45x10-06), but only when human sources were dominant. Findings suggest that community-based MST is more useful than marker-based MST to survey catchments for a range of potential pollution sources. Investing ~£230k to perform MST in-house is the best option for Northumbrian Water, and other water companies, to incorporate qPCR and sequencing into their workflows. While >3000 samples need to be processed to achieve a return on investment, the business risk remains small, and other areas of the business will benefit from this investment.en_US
dc.description.sponsorshipNorthumbrian Water and EPSRCen_US
dc.publisherNewcastle Universityen_US
dc.titleMicrobial source tracking for the UK water industryen_US
Appears in Collections:School of Engineering

Files in This Item:
File Description SizeFormat 
Robson A 2019.pdf5.06 MBAdobe PDFView/Open
dspacelicence.pdf43.82 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.