Relative Frequencies and Significance of Faecal Coliforms as Indicators Related to Water Temperature

Summary The faecal coliforms at different sites of a hypereutrophic lake near Valencia (Albufera) were identified and their relative amounts established along an annual cycle. Using lauryl tryptose broth at 35°C, followed by incubation at 44.4°C in 2% brilliant green bile, Escherichia coli and Klebsiella pneumoniae are practically the only coliforms present. A positive correlation was found between the water temperature and the relative amount of these two coliforms: K. pneumoniae predominates at high water temperatures, whereas E. coli shows preponderance during the cold period. The role of K. pneumoniae as the only faecal indicator under the circumstances described in the work is emphasiz…