Extraction and Purification of Plastoglobules from Photosynthetic Bacteria

Begin with a culture of cyanobacteria, which are photosynthetic bacteria.

These bacteria contain lipid-rich plastoglobule droplets and thylakoid membranes, which are folded membranous structures rich in photosynthetic pigments.

Centrifuge the culture and discard the supernatant to remove bacteria-produced extracellular polysaccharides. Wash the pellet, then resuspend it in a buffer.

Use a high-pressure homogenizer to generate shear force, which disrupts cell walls and membranes.

Rupture of the thylakoid membranes releases photosynthetic pigments into the lysate. The pigment release causes a color change that indicates cell disruption and plastoglobule release.

Load the lysate into centrifuge tubes, then add a sucrose solution to form a density gradient.

Centrifuge to separate cellular components by density.

The thylakoid and other heavier components pellet at the bottom, while the low-density plastoglobules float to the top as a distinct band.

Collect the plastoglobule fraction and store it by freezing for further analysis.

Grow 50 milliliters of synechocystis species PCC 6802 culture in BG11 media for 7 to 10 days to reach the stationary phase.

Using a spectrophotometer, adjust the cell den