@article{mbs:/content/journal/micro/10.1099/00221287-5-3-576, author = "ff. Edward, D. G. and Fitzgerald, W. A.", title = "Cholesterol in the Growth of Organisms of the Pleuropneumonia Group", journal= "Microbiology", year = "1951", volume = "5", number = "3", pages = "576-586", doi = "https://doi.org/10.1099/00221287-5-3-576", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-5-3-576", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "SUMMARY: Representative strains of the pleuropneumonia group, originally isolated from animals, grew well on a basal medium containing infusion broth, peptone, yeast extract and agar when this was further enriched with horse serum. The serum could be replaced by an ethereal extract of egg-yolk and fractionation of this suggested that cholesterol might be the active substance promoting growth. Growth was obtained when cholesterol (0ยท01 mg./ml.) was added to the basal medium, together with starch or bovine albumin. Addition of the acetone-insoluble fraction of egg-yolk with cholesterol gave better results, growth of six of the eight strains tested being equal to that on serum agar; the lecithin and kephalin fractions after purification were less effective. No growth was obtained when starch, bovine albumin or the acetone-insoluble lipid was added to the medium without cholesterol. Cholestanol and stigmasterol were as effective as cholesterol in promoting growth. Oleic acid in high concentrations (> 0.05 mg./ml.) inhibited growth. Both lipid and protein fractions of serum appeared to be concerned in its ability to promote growth.", }