Isolation and characterization of new strains of cholesterol-reducing bacteria from baboons

Abstract

Nine new strains of cholesterol-reducing bacteria were isolated from feces and intestinal contents of baboons. Cholesterol-brain agar was used for the primary isolation and subsequent biochemical tests were done in a lecithin-cholesterol broth containing plasmenylethanolamine and various substrates. All strains had similar colony and cell morphology, hydrolyzed the .beta.-glucosides esculin and amygdalin, metabolized pyruvate, and produced acetate and acetoin. Unlike previously reported strains, the 9 new strains did not require cholesterol and an alkenyl ether lipid (e.g., plasmalogen) for growth; only 2 strains reduced cholesterol in the absence of the plasmalogen. These 2 strains also produced succinate as an end product. Carbohydrate fermentation was variable; some strains produced weak acid (pH 5.5-6.0) from only a few carbohydrates, whereas other strains produced strong acid reactions (pH .ltoreq. 5.5) from a wide variety of carbohydrates.