[Sterol transformation by Escherichia]

The use of the Liebermann-Burhard reaction and the thin-layer chromatography of nonsaponifiable lipids of culture medium (donor blood serum) permitted the isolation of three biological variants of Escherichia in the process of their 48-hour cultivation in this medium. The cholesterol-destroying variant of Escherichia is characterized by a decrease in the content of total, free, esterified cholesterol and a decrease in the occurrence of fractions corresponding to cholesterol, delta 4-cholestenone-3, delta 5-cholestenone-3), as well as nonsaponifiable lipid, where Rf was equal to 0.36; two fractions of labeled nonsaponifiable lipids, not corresponding to cholesterol, appeared on plasma with sodium acetate-1-14C. Cholesterol-transforming biovars produced insignificant changes in the content of chemically determined cholesterol in the medium, but in plasma nonsaponifiable lipid with Rf = 0.26 and other less polar lipids were found. Escherichia strains increasing the amount of chemically determined cholesterol in the process of their growth more frequently transformed or used nonsaponifiable lipids with Rf = 0.26 and 0.42. As a rule, the occurrence of cholesterol and less polar lipids increased. The sodium acetate-1-14C was incorporated into 3-4 fractions of nonsaponifiable lipids, one of them being identified as cholesterol.