The effects of temperature and salinity on the phospholipid and fatty acid composition of a halotolerant, psychrotolerant bacterium isolated from Antarctic dry valley soil [microform] / by Karen Joy Miller
- Bib ID:
- 3287506
- Format:
- Book and Microform
- Author:
- Miller, Karen Joy, 1956-
- Description:
- 150 p.
- Summary:
-
A Gram-positive, halotolerant, psychrotolerant coccus was isolated from saline Antarctic Dry Valley soil. The isolate, strain A4a, was best classified as a member of the genus Planococcus of the family Micrococcaceae. This classification was based primarily on the guanine plus cytosine content of the DNA, the phospholipid composition, and the obligately aerobic nature of the isolate. Planococcus strain A4a was capable of growth over wide ranges of temperature (0-40(DEGREES)C) and NaCl concentrations (0-2.0 M). When the temperature of growth or the NaCl concentration of the growth medium was varied, the phospholipid and fatty acid composition of planococcus strain A4a were shown to be significantly altered.
In response to changes in growth temperature, the alterations in fatty acid composition were consistent with a temperature regulated mechanism of membrane fluidity modulation. When the NaCl concentration of the growth medium was increased, the relative amount of anionic phospholipid increased. The relative increase of anionic phospholipid resulted from a decrease in phosphatidylethanolamine content with a concomitant increase in cardiolipin content. Planococcus strain A4a was found to be generally halotolerant to a variety of chloride and sulphate salts. Growth in the presence of high concentrations of these salts resulted in alterations in both the relative phospholipid and fatty acid composition of the bacterium.
The alterations in fatty acid composition appeared to result primarily from the osmolality of the growth medium. The alterations in phospholipid headgroup composition, however, were significantly affected by the nature of the cationic species present within the growth medium. Cells grown in the presence of high concentrations of monovalent cationic salts contained elevated cardiolipin to phosphatidylglycerol ratios as compared with control cells. The cardiolipin to phosphatidylglycerol ratio, however, was not elevated when cells were grown in the presence of high concentrations of divalent cationic salts. It was proposed that cardiolipin may function to provide divalent cations to the membrane surface and/or increased membrane stability to the membrane of this bacterium when cells are grown in media containing high concentrations of monovalent cationic salts.
- Notes:
-
- (UnM)AAI8410317
- Source: Dissertation Abstracts International, Volume: 45-01, Section: B, page: 0072.
- Thesis (Ph.D.)--University of Massachusetts Amherst, 1984.
- Reproduction:
- Microfiche. Ann Arbor, Mich.: University Microfilms International.
- Subject:
- Biology, Microbiology
- Other authors/contributors:
- University of Massachusetts Amherst
- Copyright:
-
In Copyright
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Copyright status was determined using the following information:
- Material type:
- Literary Dramatic Musical
- Published status:
- Unpublished
- Creation date:
- 1984
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