Abstract
Chlorosomes are the light harvesting structures of green photosynthetic bacteria. Each chlorosome from green sulfur bacteria houses hundreds of thousands of bacteriochlorophyll molecules in addition to smaller amounts of chlorobiumquinone and carotenoids. In electron microscopy studies, chlorosomes exhibit different appearances depending on the fixation method used. Fixation with osmium tetroxide results in electron-transparent chlorosomes. Fixation with potassium permanganate results in clearly delineated electron-dense chlorosomes. This fixation method features an electron-transparent area in the interior of the chlorosome. In addition to electron density patterns that can be considered compositions of rod-shaped elements, chlorosomes exhibit a striation pattern that is oriented parallel to the longitudinal axis. Treatment with osmium tetroxide followed by potassium permanganate treatment results in a more diffused density distribution that outlines connecting elements between the chlorosome and the cytoplasmic membrane, and connecting elements between the cytoplasmic membrane and the outer membrane, which act as a diffusion barrier for electron density.
Original language | English (US) |
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Pages (from-to) | 145-154 |
Number of pages | 10 |
Journal | Photosynthesis research |
Volume | 86 |
Issue number | 1-2 |
DOIs | |
State | Published - Nov 2005 |
Keywords
- Chlorosome
- Electron microscopy
- Fixation protocol
- Green sulfur bacteria
- Ultrastructure
ASJC Scopus subject areas
- Biochemistry
- Plant Science
- Cell Biology