The membrane lipids of Halobacterium halobium |
| |
Authors: | Carolyn L. Marshall and A. D. Brown |
| |
Affiliation: | Department of Microbiology, University of New South Wales, Kensington, Sydney, N.S.W. 2033, Australia |
| |
Abstract: | The lipid content of the cell membrane of Halobacterium halobium increased from about 15% to 21% during exponential growth of the organism. Total lipid phosphorus more than doubled during the growth cycle. The mixture of membrane lipids from stationary-phase organisms was similar to lipid mixtures from whole cells of other halobacteria inasmuch as 80% of the lipid phosphorus occurred in a diether analogue of phosphatidylglycerophosphate and an additional 7.5% occurred in the ether analogue of phosphatidylglycerol. The lipid mixture was more complex than those reported for other halophils, however, 12 components being recognized in the acetone-insoluble fraction and 17 in the acetone-soluble fraction. There were major changes in the proportions of some minor components of the acetone-insoluble fraction during a growth cycle. Three nitrogenous lipids were recognized in the acetone-insoluble fraction, but all were present in relatively low proportion. One, which was not a phospholipid, contained a bound peptide. Of the 17 acetonesoluble compounds, 15 were pigments. The major carotenoids were alpha- and beta-bacteriorubrin. The carotenoid pigments occurred at maximal concentration after 6-7 days' growth. |
| |
Keywords: | |
|
|