Combined Effect of Ferric Chloride and Mercuric Chloride on the Growth of Cyanobacteria Anacystis nidulans

1. Combined Effect of Ferric Chloride and Mercuric Chloride on the Growth of Cyanobacteria Anacystisnidulans By Ted Handler, Farrell Parker, Alex Lewis, and Nick Reed

2. Dr. Lee H. Lee

3. Background Information Industry spills massive amounts of heavy metals such as mercury, selenium, ferric chloride, and mercuric chloride in our water supply. This study tests the effects of ferric and mercuric chloride on the growth of Anacystisnidulans as an indicator of life in our waters.

4. Anacystisnidulans • Small • Sensitive • Photosynthetic • Simple • Provide an indication of heavy metal pollution on metabolic activities of higher organisms in the ecosystem.

5. Mercury in any form is toxic. Toxic effects can result from vapor inhalation, ingestion, injection, or absorption through the skin. Hg accumulates mostly in the kidney, causing significant renal damage. Chronic exposure leads to accumulation within the brain, causing neurological symptoms and birth defects. Toxicity of Mercury

6. Iron as anEssential Micronutrient • Mineral needed in small amounts for body to stay healthy. • Found in meat, fish, and poultry. • Functions in the transport and storage of oxygen. • Involved in DNA synthesis and catecholamine metabolism.

7. Toxicity of Iron • Toxicity most common in children. • Toxicity occurs when free iron levels exceed the iron binding capacity of transferrin in blood. • Free iron damages many organs by direct cellular toxicity.

8. Materials • 4 Flasks • 4 Cuvettes • Disposable Pipettes • 5 mL sterile pipettes • Cotton • Cloth (breathable) • Foil • Tape • 3M Medium • Cadmium and Ferric chloride • Hand Tally Counters • Microscope • Micropipettes

9. Procedure • We made a 3M medium for cell growth, using pipettes and micropipettes, and ten compounds. • We adjusted the pH to 7.95. • We sterilized it by autoclaving the medium at 121° C. • We mixed the Anacystisnidulanswith the medium. Then distributed it into 4 flasks. Each flask with 100mL of Anacystisnidulansculture. • 1st flask had no heavy metals, this was our control. • 2nd flask has 0.5 mg/L of HgCl2 and 50 mg/L of FeCl3. • 3rd flask has 1 mg/L of HgCl2 and 50 mg/L of FeCl3. • 4th flask has 5 mg/L of HgCl2 and 50 mg/L of FeCl3.

10. Procedure (cont’d) • We used a micropipette to transfer HgCl2 and FeCl3 • Then we observed the Anacystisnidulans every 3 or 4 days by two methods. • First, we used a spectrophotometer to measure absorbance levels at 750nm. • Second, we used hand tally counters to count the cells under a microscope, on a special slide called a hemacytometer, or a bacterial counting chamber.

11. Results: Control

12. Results: Flask 2

13. Results: Flask 3

14. Results: Flask 4

15. pH Results

16. Conclusions After extensive growth of Anacystisnidulansin flasks 2 and 3, a resistance is built to the mercuric chloride and ferric chloride. The cyanobacteria thrives after growing a resistance and grows at a rate faster then that of the control. However, after a stationary point is reached at a high enough concentration, the cyanobacteria begin to die.

17. Conclusions (cont’d) In flask 4, the concentrations of the heavy metals were too high for the cyanobacteria to be able to resist it. The cyanobacteria had no chance to grow, and began to die very rapidly, from the beginning of the experiment.

18. Thank You!