The Effect of Temperature and Sodium Bicarbonate on E. coli Sonja Berger – Fraser High School Najah Mubashira – Warren Mott High School

Words to Know Agar Fleaker Dilutions Inoculation Sodium Bicarbonate Transfer Loop Berger - Mubashira

Bacteria in the Body Your body consists of 10 trillion cells. Your gut has 100 trillion microorganisms. 10 times more bacteria than cells. The gut flora help in the digestion process. One of these species of microorganisms are E. coli. Berger - Mubashira

E. coli Escherichia coli Breaks down food Extracts nutrients from the food o Vitamins K, B, and B- complex Berger - Mubashira

Where Is It Found? Large intestines Feces Water Systems Food stine-diagram.svg/250px-Intestine-diagram.svg.png Berger - Mubashira

Friend or Foe? Human digestion Food poisoning Water contamination Berger - Mubashira

In the Large Intestines Berger - Mubashira

Irrigation systems Municipal Water Ways Food items get processed E. coli Through Water Systems Through the sewer Berger - Mubashira

Question Presented in different conditions, in which condition does E. coli grow best? Different pH level Different temperature Sodium bicarbonate levels Temperature levels Berger - Mubashira

Sodium Bicarbonate NaHCO 3 Increases pH level Alkaline salt Kills Bacteria Found in Baking Soda Berger - Mubashira

Sodium Bicarbonate and E. coli pH 6 o 0 grams of sodium bicarbonate pH 7 o pH of water o Neutral o Optimal pH level to grow E. coli o 0.51 grams of sodium bicarbonate pH 8 o Kills more bacteria o 1 gram of sodium bicarbonate Berger - Mubashira

Temperature Ideal temperature for E. coli growth is 37°C. Bacteria like warm temperatures Low and high levels Optimal temperature growth range o 25 °C – 40 °C More bacteria would grow in 38°C Berger - Mubashira

Hypothesis If the temperature of the incubator is at its highest temperature, 38°C, and the sodium bicarbonate is at 0 grams, then the Escherichia coli will have its highest growth rate. Berger - Mubashira

Design of Experimental Values Amount of Sodium Bicarbonate used Temperatures at which DOEs were placed Sodium bicarbonate (g)Temperature (°C) -Standar d Berger - Mubashira

Experiment Overview Agar – to grow the E. coli on Add sodium bicarbonate to agar Dilute bacteria Place in incubators set at 36 °C, 37 °C, 38 °C After 24 hrs, count colonies with the unaided eye Berger - Mubashira

Dilutions Video Berger - Mubashira

Average Number of Colonies Grown The (-, -) group grew the most E. coli colonies with 6,051 colonies on average. The (+, -) group grew the least amount of colonies with 58 colonies on average. DOE E. Coli Colonies (Sodium Bicarbonate, Temperature) (+, +)(+, -)(-, +)(-, -)Standard Average Berger - Mubashira

Standards Graph Berger - Mubashira

Effect of Sodium Bicarbonate As sodium bicarbonate increases, colonies decrease by 3821 colonies. Berger - Mubashira

Effect of Temperature As temperature increased, the number of colonies decreased by Berger - Mubashira

Interaction Effect The slopes differ, meaning there is an interaction effect. Berger - Mubashira

Interaction Effect Berger - Mubashira

What Does This Mean? The results show that higher sodium bicarbonate has a negative growth affect on E. coli Sodium bicarbonate is an alkaline salt and salt kills bacteria. E. coli like it better in more acidic environments than alkaline. E. coli prefer temperatures closer at about 36°C. Berger - Mubashira

Results The original hypothesis that the colonies would grow best at low sodium bicarbonate and high temperature, (-, +), was rejected. The colonies in the (-, -) low sodium bicarbonate and low temperature Petri dishes grew the most. The high sodium bicarbonate low temperature (+, - ) grew the least amount of E. coli. Berger - Mubashira

Design Flaws and Errors Some trials were tested on different days There was extra bacteria in the (+, +) DOEs in trial 3 Limit on balances Sodium bicarbonate measuremets Berger - Mubashira

Real World Connection Use alkaline pH level materials to kill bacteria Body pH lessens Bacteria overgrowth Berger - Mubashira

Further Research More time Wider range of E. coli Wider range of pH Wider range in temperature Be consistent with the materials used Berger - Mubashira

Acknowledgements Mrs. Tuyen C. Duddles Cathleen Saraza Kristen Lidwell Patrick Osantowske Andrew DeSantis Jacob Arche Evan Gonzales Berger - Mubashira

Works Cited Images o o o o o Berger - Mubashira

Works Cited “Bacteria - Characteristics of Bacteria” science.jrank.org Net Industries and Its Licensors. 28 February Web. 31 January 2011 Baker, Ron. “E. coli Culturing.” newton.dep.anl.gov/ University of Chicago Newton BBS 15 December February Web. 29 January 2011 < mole00676.htm> “E. coli Facts.” ota.com. Organic Trade Association. 17 February Web. 30 January 2011 “E. coli – Just the Facts” Web. 20 March < General/Articles/E--Coli---Just-the-Facts/> Don, Sarah. “Optimal Conditions for the Growth of E. coli.” scribd.com/. Scribd Inc. 25 January Web. 28 January < Optimal-Conditions-for-the-Growth-of-E-Coli> Berger - Mubashira

Works Cited Hargreaves, Richard. “Alkaline Salt - Sodium bicarbonate (bicarb soda)” ironpower.biz Ironpower Web. 28 January 2011 Kimball, J. “The Human Gastrointestinal (GI) Tract” John W. Kimball Web. 5 February Santa, Janin. “The Effect of Temperature on Bacterial Growth” ehow.com. Demand Media, Inc. 28 February Web. 28 January < about_ _effect-temperature-bacterial-growth.html> Williams, Martin. “How to Grow E. Coli in a Petri Dish” Demand Media, Inc. 28 February Web. 2 February 2011 < how_ _grow-ecoli-petri-dish.html> “What is normal body temperature?” officialhealthcentral.com OfficialHealthCentral. 14 January Web. 26 January Berger - Mubashira

Any Questions?? Berger - Mubashira