Abstract
In view of previously published reports of localized membrane growth in exponentially growing Bacillus megaterium and in sporulating Bacillus cereus, an attempt was made to describe phospholipid metabolism and the topology of membrane synthesis during sporulation in B. megaterium. The cells were pulsed with radioactive glycerol or acetate at the time of septum formation, and the specific activity of the lipid fraction was measured at various times through the free spore stage. The bulk of the material labeled during septation could not be recovered in the spore. Rather, it was found that the labeled lipid fraction underwent considerable turnover during spore development. Additionally, other experiments revealed that the lipid made before the initiation of sporulation was also subject to extensive turnover. In order to minimize both the confounding effects of lipid turnover and the possible presence of lateral diffusion of labeled lipid in the membrane, autoradiography of cells pulse labeled with radioactive glycerol at the time of septation was performed; a symmetrical grain distribution resulted. Thus, despite previously published suggestions to the contrary, the current experimental techniques could not demonstrate the existence of localized membrane synthesis in B. megaterium during sporulation.
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Selected References
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- BLIGH E. G., DYER W. J. A rapid method of total lipid extraction and purification. Can J Biochem Physiol. 1959 Aug;37(8):911–917. doi: 10.1139/o59-099. [DOI] [PubMed] [Google Scholar]
- Bertsch L. L., Bonsen P. P., Kornberg A. Biochemical studies of bacterial sporulation and germination. XIV. Phospholipids in Bacillus megaterium. J Bacteriol. 1969 Apr;98(1):75–81. doi: 10.1128/jb.98.1.75-81.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Daniels M. J. Lipid synthesis in relation to the cell cycle of Bacillus megaterium KM and Escherichia coli. Biochem J. 1969 Dec;115(4):697–701. doi: 10.1042/bj1150697. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FITZ-JAMES P. C. The phosphorus fractions of Bacillus cereus and Bacillus megaterium. I. A comparison of spores and vegetative cells. Can J Microbiol. 1955 Aug;1(7):502–519. doi: 10.1139/m55-064. [DOI] [PubMed] [Google Scholar]
- Freeman C. P., West D. Complete separation of lipid classes on a single thin-layer plate. J Lipid Res. 1966 Mar;7(2):324–327. [PubMed] [Google Scholar]
- Fukuda A., Gilvarg C. The relationship of dipicolinate and lysine biosynthesis in Bacillus megaterium. J Biol Chem. 1968 Jul 25;243(14):3871–3876. [PubMed] [Google Scholar]
- Garrick-Silversmith L., Torriani A. Macromolecular syntheses during germination and outgrowth of Bacillus subtilis spores. J Bacteriol. 1973 May;114(2):507–516. doi: 10.1128/jb.114.2.507-516.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Green E. W., Schaechter M. The mode of segregation of the bacterial cell membrane. Proc Natl Acad Sci U S A. 1972 Aug;69(8):2312–2316. doi: 10.1073/pnas.69.8.2312. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hitchins A. D., Slepecky R. A. Bacterial sporulation as a modified procaryotic cell division. Nature. 1969 Aug 23;223(5208):804–807. doi: 10.1038/223804a0. [DOI] [PubMed] [Google Scholar]
- Jost P., Brooks U. J., Griffith O. H. Fluidity of phospholipid bilayers and membranes after exposure to osmium tetroxide and gluteraldehyde. J Mol Biol. 1973 May 15;76(2):313–318. doi: 10.1016/0022-2836(73)90394-x. [DOI] [PubMed] [Google Scholar]
- Korn E. D. Structure of biological membranes. Science. 1966 Sep 23;153(3743):1491–1498. doi: 10.1126/science.153.3743.1491. [DOI] [PubMed] [Google Scholar]
- Kornberg R. D., McConnell H. M. Lateral diffusion of phospholipids in a vesicle membrane. Proc Natl Acad Sci U S A. 1971 Oct;68(10):2564–2568. doi: 10.1073/pnas.68.10.2564. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mindich L., Dales S. Membrane synthesis in Bacillus subtilis. 3. The morphological localization of the sites of membrane synthesis. J Cell Biol. 1972 Oct;55(1):32–41. doi: 10.1083/jcb.55.1.32. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morrison D. C., Morowitz H. J. Studies on membrane synthesis in Bacillus megaterium KM. J Mol Biol. 1970 Apr 28;49(2):441–459. doi: 10.1016/0022-2836(70)90256-1. [DOI] [PubMed] [Google Scholar]
- Singer S. J., Nicolson G. L. The fluid mosaic model of the structure of cell membranes. Science. 1972 Feb 18;175(4023):720–731. doi: 10.1126/science.175.4023.720. [DOI] [PubMed] [Google Scholar]