Effect of freshwater sediment characteristics on the persistence of fecal indicator bacteria and genetic markers within a Southern California watershed.

摘要: Abstract In this study, the aging of culturable FIB and DNA representing genetic markers for Enterococcus spp. (ENT1A), general Bacteroides (GB3), human-associated (HF183) in freshwater sediments was evaluated. Freshwater sediment collected from four different sites within upper lower reach Topanga Creek Watershed two additional comparator Santa Monica Bay, a total six sites. Untreated (ambient) oven-dried (reduced microbiota) inoculated with 5% sewage artificial freshwater. Microcosms were held 21-day period sampled on day 0, 1, 3, 5, 7, 12, 21. There substantial differences decay among tested, rates related to characteristics. ambient sediments, smaller particle size higher levels organic matter nutrients (nitrogen phosphorus) associated increased persistence GB3 marker Escherichia coli (cEC) enterococci (cENT). The HF183 exhibited of −0.50 to −0.96 −1 , which 2–5 times faster certain than ENT1A markers. decayed at between −0.07 and −0.28 and −0.10 to −0.44 cEC cENT between −0.22 and −0.81 and −0.03 and −0.40 respectively. all indicators potential limited growth observed. A simplified two-box model using generated microcosm experiments applied reaches Canyon watershed order provide context variability predicted concentrations (90 MPN g ) versus (530 MPN g low (below LLOQ) both watersheds. It is important consider when evaluating fecal contamination even one watershed.