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Sunlight Inactivation of Human Polymerase Chain Reaction Markers and Cultured Fecal Indicators in River and Saline Waters
Author(s) -
Gilpin Brent J.,
Devane Megan,
Robson Beth,
Nourozi Fariba,
Scholes Paula,
Lin Susan,
Wood David R.,
Sinton Lester W.
Publication year - 2013
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143012x13560205144290
Subject(s) - feces , saline , polymerase chain reaction , chemistry , sunlight , saline water , environmental chemistry , biology , microbiology and biotechnology , environmental science , ecology , biochemistry , salinity , gene , endocrinology , physics , astronomy
Decay rates for sunlight inactivation of polymerase chain reaction (PCR) markers for total Bacteroidales , human‐specific Bacteroidales , Escherichia coli , and Bifidobacterium adolescentis relative to cultured E. coli were investigated. The experiment used 100‐L chambers of fresh water and seawater (paired with dark controls) seeded with human sewage and exposed to natural sunlight over three summer days. Culturable E. coli levels in sunlight‐exposed chambers decreased by at least 3 logs on day 1, and by day 3 a total reduction of 4.5 to 5.5 logs was achieved in fresh water and seawater, respectively. In contrast, PCR detection of the four gene targets in sunlight‐exposed chambers reduced by no more than 2 logs over the duration of the study ( k t < 0.071 log e units h −1 ). Under these experimental conditions, PCR markers are considerably more conservative than culturable E. coli and can persist for extended periods of time following inactivation of E. coli .