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Many brasses were almost completely bactericidal at 4 °C within 180–360 minutes. The rate of total microbial death on four bronzes varied from within 50–270 minutes at 20 °C, and from 180 to 270 minutes at 4 °C. The kill rate of E. coli O157 on copper-nickel alloys increased with increasing copper content. Zero bacterial counts at room ...
The fecal coliform assay is intended to be an indicator of fecal contamination; more specifically of E. coli which is an indicator microorganism for other pathogens that may be present in feces. Presence of fecal coliforms in water may not be directly harmful, and do not necessarily indicate the presence of feces.
E. coli is a chemoheterotroph whose chemically defined medium must include a source of carbon and energy. [16] E. coli is the most widely studied prokaryotic model organism, and an important species in the fields of biotechnology and microbiology, where it has served as the host organism for the majority of work with recombinant DNA. Under ...
Escherichia coli have an incubation period of 12–72 hours with the optimal growth temperature being 37 °C. Unlike the general coliform group, E. coli are almost exclusively of fecal origin and their presence is thus an effective confirmation of fecal contamination. Most strains of E. coli are harmless, but some can cause serious illness in ...
A review of 22 studies in 1998 [10] confirmed that the health risks for swimmers increased as the number of indicator bacteria increased in recreational waters and that E. coli and enterococci concentrations correlated best with health outcomes among all the indicators studied. The relative risk (RR) of illness for swimmers in polluted ...
By testing for coliforms, especially the well known Escherichia coli (E. coli), which is a thermotolerant coliform, one can determine if the water has possibly been exposed to fecal contamination; that is, whether it has come in contact with human or animal feces. It is important to know this because many disease-causing organisms are ...
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This would be shown either as F 10 121 = 10 minutes (Celsius) or F 18 250 = 10 minutes (Fahrenheit). A lethal ratio (L) is also a sterilizing effect at 1 minute at other temperatures with (T). = / where T Ref is the reference temperature, usually 250 °F (121 °C); z is the z-value, and T is the slowest heat point of the product temperature.