出版社:American Society for Biochemistry and Molecular Biology
摘要:Many anaerobic bacteria have a high proportion of 1-alk-1′-enyl ethers (plasmalogens) among their phospholipids. We have examined the effects of growth temperature on the phospholipid, fatty acid, and alk-1-enyl group compositions of Clostridium butyricum . When the growth temperature was decreased from 37°C to 25°C, the proportion of glycerol phosphoglycerides (the sum of phosphatidylglycerol and the corresponding plasmalogen) increased at the expense of the ethanolamine and N -methylethanolamine phosphoglycerides. Analysis of the proportion of these lipids present in the diacyl and 1-alk-1′-enyl-2-acyl forms has shown a substantial increase in the plasmalogen form of the glycerol phosphoglycerides and a decrease in the plasmalogen forms of the ethanolamine and N -methylethanolamine phosphoglycerides. An analysis of the fatty acids and alk-1-enyl groups isolated from the total phospholipids of cells grown at 25°C, 30°C, and 37°C has shown a general increase in the proportions of unsaturated and cyclopropane hydrocarbon chains at lower growth temperatures. When the temperature was lowered from 37°C to 25°C, the fatty acids had progressively more unsaturated and cyclopropane chains and fewer saturated chains. The alk-1-enyl groups, in particular those from the ethanolamine and N -methylethanolamine plasmalogens, were more saturated at 30°C than at 37°C. When the growth temperature was lowered to 25°C, there was little further change in the degree of unsaturation of the alk-1-enyl groups.