Eucaryote thermophily: role of lipids in the growth of Talaromyces thermophilus

The effects of growth temperature on the fatty acid composition of the phospholipids of the fungus Talaromyces thermophilus were investigated. This thermophilic organism was unable to increase the degree of unsaturation of its fatty acids when shifted from high to low growth temperatures. Inhibition of fatty acid synthesis by the antibiotic cerulenin was reversed by the addition of a mixture of palmitic, stearic, and oleic acids and ergosterol. The data obtained were consistent with the hypothesis that the thermophilic character of T. thermophilus is due to metabolic limitations that restrict its ability to regulate membrane fluidity.</jats:p

Asparaginase production by human clinical isolates of Vibrio succinogenes

Three human isolates of Vibrio succinogenes produced asparaginase. Apparent Km's were 87,220, and 320 microM. The rate of glutamine hydrolysis was between 2.8 and 3.5% of the rate of asparagine hydrolysis. Asparaginase production was not induced by ammonium ions, and enzyme yields were lower than those obtained with the rumen strain.</jats:p