Procedure

1. Three different strains of cyanobacteria cultures were selected for this investigation. Three bottles of each strain were prepared, and carbon dioxide was bubbled into each bottle at different concentrations.  Concentrations used were 100 ppm, 350 ppm (air), and 750 ppm.  The bottles were placed in front of a diffuse light source similar to normal living conditions for the cyanobacteria with the carbon dioxide bubbling continuously.

2. Samples were taken from the bottles at the following intervals:
Day 0 (initial samples)
Day 2
Day 5

Measure of Biological Parameters
3. Cell Counts ?
The samples were filtered and placed on microscope slides to be observed under oil immersion on a phase-contrast microscope.  The cells were visually counted and data recorded.  This data was used to calculate growth rate.

4. Fluorescence of Chlorophyll a
Fluorescence of chlorophyll a was measured in a fluorometer.  This measure is an indicator of cell number.  This data was used to calculate growth rate.

Pigment Measurements
5. Phycobilins
The phycobilins were released from the cyanobacterial cells by the freeze-thaw alumina pestle method.  The spectrophotometer was used to measure the optical density of the pigments by scanning the range of wavelengths from 565 nm to 650 nm.  The presence of phycocyanin ,phycoerythrin, and allophycocyanin were determined by locating the peaks of maximum absorbance.

6. Chlorophyll a
The chlorophyll a was extracted using acetone.  The spectrophotometer was used to measure the optical density of the pigment by scanning the range of wavelengths from 480 nm to 750 nm.  Absorbance peaks located the chlorophyll pigments, and the amounts of the pigments were determined.
 

Q:  Is it possible to reduce current carbon dioxide emissions?

A:  Reducing CO2 emissions could be achieved by reducing humans demand for energy, altering the way energy is used, changing the method of producing and delivering energy and ultimately switching to "low" or "no" carbon fuels.  Unfortunately stabilizing CO2 levels at the current level would require reducing current global CO2 emissions by 65-85%.  This is highly unlikely.  The International Energy Agency projected that CO2 emissions will increase by nearly 50% between 1990 and 2010.