ISSN:
1432-072X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The pigments of two strains of extremely thermo-resistant bacteria were extracted and examined spectrophotometrically. Both strains contain α-carotene as the main pigment according to the spectral characteristics of the pigment in various solvents. According to quantitative data Thermus aquaticus contains more than one hundred times as much of the pigment than is found in strain YT-G, representing almost 80% of the total lipid. The carotene of strain YT-G is destroyed by hot saponification, while that of T. aquaticus resists that procedure without alterations. T. aquaticus contains a small amount of a second pigment with absorption maxima at 370, 400 and 420 mμ. Solubilization of the membrane of spheroplasts derived from acetate-C14-labelled cells of T. aquaticus, followed by separation of the crude membrane fraction, showed that about 50% of the C14 is associated with the membrane fraction. More than 90% of the C14 is recovered in the yellow supernatant of the acetone-extracted crude membrane fraction, showing that a rapid incorporation of the label into the pigment occurs. The assumption that the pigment is associated with the membrane is supported by submicroscopical observations: T. aquaticus has a well-defined cytoplasmic membrane, and on top of this a sandwiched layer, which is embedded in a very electron-dense material, that we assume to consist of the pigment. Strain YT-G which contains only minute quantities of the same pigment, does not possess this kind of an outer membrane, but shows only a cytoplasmic membrane envelopped by the cell wall.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00409311
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