Growth inhibition of Mycoplasma by inhibitors of polyterpene biosynthesis and its reversal by cholesterol.

Smith, Paul F. (University of South Dakota, Vermillion), and Carl V. Henrikson. Growth inhibition of Mycoplasma by inhibitors of polyterpene biosynthesis and its reversal by cholesterol. J. Bacteriol. 91:1854-1858. 1966.-Compounds which inhibit enzymatic reactions in the biosynthetic pathway to carotenoids inhibited growth of a sterol-nonrequiring species, Mycoplasma laidlawii, strain B, and M. hominis, strain 07. Since M. hominis lacks the enzymes for polyterpene biosynthesis, the inhibitory compounds must act also at other sites. Most inhibitors exerted a lytic effect at bactericidal levels. The inhibition of M. laidlawii is reversed by exogenous cholesterol. M. laidlawii exhibited a greatly increased content of cholesterol and a greatly decreased content of carotenoids when grown in the presence of phenethylbiguanide and cholesterol. These results are considered as further evidence for a common function for sterols and carotenols in Mycoplasma.