Tap Water Intrusion Effects on Microbial Life

1. Tap Water Intrusion Effects on Microbial Life Anthony DeRenzo Grade 10 Pittsburgh Central Catholic High School

2. Surface Runoff • Is part of the water cycle and describes the water that flows over a land surface. • Can come from precipitation and flow into natural bodies of water. • It can have an effect on the marine life in the various water sources it enters.

3. Types of Surface Runoff • Petroleum • Pesticides • Many organic and inorganic chemicals • Silt • Fertilizers • Tap Water

4. Tap Water • Water directly drawn from a faucet • Used in everyday appliances such as washing machines, dishwashers, and showers. • Contains a wide variety of components.

5. Sodium Nitrate • A colorless, odorless crystalline compound. • Formed by a chemical reaction of sodium chloride and nitric acid. • Used in the production of explosives, fertilizers, and potassium nitrate, and also is used in the preservation of meats.

6. Relationship • People make use of sodium nitrate by growing plants with fertilizers. • People make use of tap water through sewage systems, plumbing, and many other activities. • A fraction of these two substances undoubtedly enter natural water sources. • There are numerous species of macroscopic and microscopic organisms that could be affected by runoff that contains either sodium nitrate or tap water.

7. Saccharomyces Cerevisiae • A type of yeast that reproduces by budding. • The most useful yeast. It is used in baking and brewing. • A eukaryote that shares the complex internal structure of plants and animals.

8. Escherichia coli • A type of bacteria that is found in warm-blooded animals. It can be found in the fecal matter as well as the intestines. • Some strains posses flagella and other do not. • It can grow by both aerobic and anaerobic respiration.

9. Purpose • To test different concentrations of tap water with a controlled concentration of sodium nitrate on two forms of microbial life: Saccharomyces cerevisiae and Escherichia coli.

10. Null and Alternative Hypotheses • Null: sodium nitrate will not significantly affect the population survivorship of Saccharomyces cerevisiae or Escherichia coli. • Null: the addition of different tap water concentrations will not significantly affect the population survivorship of Saccharomyces cerevisiae or Escherichia coli. • Alternative: the addition of different concentrations of tap water with the controlled concentration of sodium nitrate will adversely affect the microbial models.

11. Materials • 40 YEPD and 40 LB agar plates • container of ethanol • 5 spreaders • 8 SDF culture tubes • 1 ml of sodium nitrate • 17 ml of tap water • 5 ml pipette and micropipette • 0.22 micron syringe filter • cultures of Saccharomyces cerevisiae and Escherichia coli

12. Procedure 1 • The experimental variables, tap water and sodium nitrate, were sterile filtered with 0.22 micron syringe filters. • Samples of the microbial cultures were taken and diluted in a sterile dilution fluid to a concentration of 103 cells/ml. • The experimental variables were added to the tubes with SDF solution to create the chosen concentrations of 0%, 10%, 25%, and 50% of tap water and .1% of sodium nitrate in each group. Also, 0.1 ml of the microbial cultures was added to the tubes to create a volume of 10 ml in each tube. There were four concentration groups for each microbial culture (chart on next page), and two tubes made for each group.

13. Procedure 2

14. Procedure 3 • The solution for each group was vortexed and allowed to sit at room temperature for 1-2 minutes. • After vortexing, 0.1 ml aliquots were removed from the tubes and spread on the YEPD agar plates (S. cerevisiae) and the LB agar plates (E. coli). • The plates were set at room temperature and grown for six days. After six days, the number of surviving colonies were counted from each plate.