The membrane lipids of Halobacterium halobium.
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.
D002338:Carotenoids / Q000032:analysis; D002462:Cell Membrane / Q000032:analysis*; D002855:Chromatography, Thin Layer; D006217:Halobacterium / Q000032:analysis* / Q000254:growth & development; D008055:Lipids / Q000032:analysis*; D010455:Peptides / Q000032:analysis; D010743:Phospholipids / Q000032:analysis
D008055:Lipids; D010455:Peptides; D010743:Phospholipids; D002338:Carotenoids