, often considered the best indicator of human fecal contamination, increased by ~8% between depths of 7.5 cm and 5 cm (~1950 to 1981) and was more reliable in tracking sewage contamination than diagnostic sterol ratios.
Contributions from anthropogenic fecal sources can be characterized via the occurrence of the 5[beta]-stanol [C.sub.27] (e.g., coprostanol
and epicoprostanol) compounds [11-14, 25] that are byproducts of intestinal anaerobic microbial reduction of cholesterol in higher animals .
Eubacterium coprostanoligenes, a small gram-positive and cholesterol-reducing anaerobe, promotes the conversion of cholesterol to coprostanol
(Madden et al., 1999).
(5[beta]-cholestan-3[beta]-ol) was found at one station in BioBio Canyon (B4), one station in the BioBio River (BB-C) and two in the Itata River (I-1, I-2).
Several mechanisms for cholesterol removal by probiotics have been proposed, such as deconjugation of bile salts by bile-salt hydrolase (BSH) , assimilation of cholesterol into bacterial cell membranes , production of short-chain fatty acids (SCFAs) during the growth of probiotics , and cholesterol conversion into coprostanol
Wun C, Walker R, Litsky W (1976) The use of XAD2 resin for the analysis of coprostanol
1:45 POLYNUCLEAR AROMATIC HYDROCARBONS IN KEEGAN BAYOU, BILOXI, MS, USING COPROSTANOL
TO TRACK TRANSPORT
Of the 50 locations sampled in the study, Anne's Beach exhibited one of the highest concentrations of coprostanol
and cholesterol (indicators of human sewage).
had even a lower relative intensity compared with cholesterol and, like lathosterol, has not been reported to be present in concentrations in serum that would alter the results obtained by the CDC Reference Method for cholesterol .