Soap: The Effect Of Different Sanitation Methods In The Production Of Germs And Bacteria In Petri Dishes
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Research Question:
What is the effect of different sanitation methods in the production of germs and bacteria in Petri dishes?
Background research:
How bacteria multiplies:
Bacteria don’t reproduce the same way humans and animals do. They take in several nutrients and are multiplied by diving themselves. This happens by geometric progression, that is, one cell divides to become two, and later two becomes four, four becomes eight, eight becomes sixteen, and so on and so forth. The growth of bacteria can increase in speed depending on the conditions of the host or surface it is on. Things such as temperature, ideal nutrients, moisture, and other components could increase the speed of production, that is why we swabbed on any desired surface and swabbed it again in the petri dish, which has the nutrients and moisture adequate for bacteria growth, and also kept it in the incubator for the adequate temperature.
Bacteria can be harmful to humans in three different ways; infection, intoxication, and toxicoinfection. Most of these are caused by the ingestion of food containing bacteria. An infection, for example, happens when the microorganism itself is digested with the food and then the bacteria establishes itself in the human body and multiplies. Intoxication happens when the organism releases toxins of the bacteria and then these toxins are later ingested into the human body. The symptoms happen faster than an infection because toxins move faster throughout the body. Toxicoinfection can be assumed to be a mixture of the two, as the name says. This happens by bacteria that are non-invasive and when ingested with the food and inside the body, then start to produce and release toxins. (Cornell, 2010). 1
- (2010.). Introduction – Seafood HACCP Online Training Course. Retrieved April 27, 2020, from http://seafoodhaccp.cornell.edu/blackboard/module2/pdfmod2/mod2.pdf, http://seafoodhaccp.cornell.edu/blackboard/module2/pdfmod2/mod2.pdf
How detergent works:
A detergent is a chemical substance that people use to remove fat and other greasy substances from mainly plates and cutlery. Detergents are very likely to be a big mixture of synthetic chemicals and different kinds of substances and are present in several day-to-day cleaning products like shampoo, shaving cream, and stain removers. Either way, the biggest takeaway and most important ingredient in detergent is the surfactant, that is, surface-active agents. In an interesting way, surfactants work in a way that makes water wet things more. It helps water beat the surface tension from most surfaces and wet things more consistently. Surfactants not only attract more towards water but to dirt and grease as well, which applies more to our experiment since we weren’t using water at all. (Woodford, 2019). 2
How soap works:
Soap has basically the same purpose as the detergent as it is also a surfactant. It attracts more water and oil and grease better than other substances, that is why it is the best cleaning utensil to use, it is the most successful in the removal of germs and bacteria according to our results. Natural soap doesn’t need any synthetic additive to clean or remove dirt from surfaces because natural soap is a natural surfactant. The difference between soap and detergent is that detergent is geared more strongly towards fat and greasy substances while soap focuses on the overall and does it more effectively. (Soap and Salve Company, 2015). 3
How Alcohol works:
Hand sanitizers are a very convenient and easy way to clean your hands but it really should only be addressed if soap and water are not available, since it is not as effective. The key ingredients in hand sanitizers are carbon, oxygen, and hydrogen. What alcohol does is, differently from the soap and detergent, it destroys the disease carrying pathogens by breaking their proteins down, splitting cells, etc. However this has only appeared to be true once the concentration of alcohol is greater than or equal to 60%, meaning that hand sanitizers with the 90% concentration mark will be extremely effective in eliminating pathogens. (Hickok, 2020) 4
Independent Variable: Application of different sanitation methods
Hypothesis:
When using soap and detergent the count of germs and bacteria colonies in the petri dishes should be very low if not none because they are the most successful in the removal of germs and bacteria. Also, the petri dishes would be closed and that means that there can’t be any sort of living organism to emerge after the petri dish is closed, for that we have to keep it open for the shortest time possible.
We believe that the hand-sanitizer will not be that effective because it is rather focused on eliminating germs and bacteria rather than removing them, meaning that it is not sure that all the bacteria will be gone.
- (2019, September 13). How do detergents and soaps work? – Explain that Stuff. Retrieved April 27, 2020, from https://www.explainthatstuff.com/detergents.html
- (2015, April 18). How Does Soap Work? – Ida’s Soap Box – Chagrin Valley Soap. Retrieved April 27, 2020, from https://www.chagrinvalleysoapandsalve.com/blog/posts/how-does-soap-work/
- (2020, March 6). How do hand sanitizers work? | Live Science. Retrieved April 27, 2020, from https://www.livescience.com/hand-sanitizer.html
- https://www.explainthatstuff.com/detergents.html
- https://www.chagrinvalleysoapandsalve.com/blog/posts/how-does-soap-work/
- https://www.livescience.com/hand-sanitizer.html
Identifying Variables:
Table 1: Identifying Independent And Dependent Variable
Independent Variable Dependent Variable
The independent variables in this experiment are the different types of cleaning methods
The dependent variable is the amount of bacteria colonies that will be created afterwards and we will use that information to see the best cleaning utensil.
Table 2: Identifying Independent And Dependent Variables
Controlled Variables How It Is Controlled Why It Has To Be Controlled
Equipment used Maintaining the same beakers and the same amount of each material to avoid uncertainties.
We keep the equipment the same to avoid uncertainties and different result to each trial
Temperature and environment The petri dishes will always be placed in the incubator after any type of manipulation on our part.
This will assure us that the bacteria is growing steadily and well.
Materials:
- 12 agar plates
- Rubber gloves
- Paper towel
- Detergent
- Soap
- Hand Sanitizer
- 3 beakers
- 1 box of Q-tips
- Tape
- A pen
- The trackpad in the laptop
Risk Assessment:
Although many different types of bacteria do not pose any threat to human life, some bacteria are still able to pass different diseases that can easily be transmitted to humans. To keep any diseases from being spread from the petri dishes and the surfaces to our own bodies, always use gloves and avoid touching your face throughout the whole experiment as much as possible.
Method:
- Choose surface to be swabbed on
- Separate this chosen surface into 4 equal areas to measure different types of cleaning methods
- Add detergent, soap, and hand sanitizer to three separate beakers
- Grab a q-tip and rub it on one of the areas (for the control group, so no cleaning utensils yet) and then rub gently, with the same q-tip, on the surface of a petri dish.
- Dip a new q-tip into the beaker with the soap, and rub it on the second area of the surface until it is completely covered. Wipe off the soap with a paper towel. Then, grab another q-tip and rub it in the area that has just been cleaned by the soap, and then rub gently, with the same q-tip, on another petri dish.
- Repeat step 5 with detergent and hand sanitizer on the other two areas of the same surface.
- Place the 4 Petri dishes in the same incubator.
Repeat steps 3-7 with another 2 portions of the surface of the same chosen object, giving a total of 3 trials.
Raw Data:
Table 3: Number Of Colonies Visible To The Naked Eye Formed On The Agar Plates For The 3
Different Trials, 2 Days After The Experiment
(colonies) Trial 1 Trial 2 Trial 3
No Agent Added 5 9 5
Soap 2 0 0
Hand Sanitizer 2 0 9
Detergent 1 0 0
Table 4: Number Of Colonies Visible To The Naked Eye Formed On The Agar Plates For The 3
Different Trials, 7 Days After The Experiment
(colonies) Trial 1 Trial 2 Trial 3
No Agent Added 5 9 6
Soap 2 0 0
Hand Sanitizer 2 0 9
Detergent >30 0 0
Table 5: Number Of Colonies Visible To The Naked Eye Formed On The Agar Plates For The 3
Different Trials, 9 Days After The Experiment
(colonies) Trial 1 Trial 2 Trial 3
No Agent Added 5 10 10
Soap 2 0 0
Hand Sanitizer 2 4 9
Detergent >45 1 0
Qualitative Data:
Throughout the experiment, it can be observed that there was an gain in the intensity of the odor that was coming from the incubator where all the petri dishes were located and stored. Even though, in most cases there was no addition of colonies observed, therefore the magnitude of the previous colonies had had a meaningful increase. It also was seen that not all colonies were the same color, along with variations of shades of white and later yellow.
Processed Data:
Table 6: Initial And Final Number Of Colonies Observed To The Nake Eye Along With The (%)
Increased For Trial 1
No Agent Added Soap Hand Sanitizer Detergent
Initial Number
Of Colonies
5 2 2 1
Final Number
Of Colonies
5 2 2 45
Increase (%) 0 0 0 4400
Table 7: Initial And Final Number Of Colonies Observed To The Nake Eye Along
With The (%) Increased For Trial 2
No Agent Added Soap Hand Sanitizer Detergent
Initial Number
Of Colonies
9 0 0 0
Final Number
Of Colonies
10 0 4 1
Increase (%) 11 0 n/a n/a
Table 8: Initial And Final Number Of Colonies Observed To The Nake Eye Along With The (%)
Increased For Trial 3
No Agent Added Soap Hand Sanitizer Detergent
Initial Number
Of Colonies
5 0 9 0
Final Number
Of Colonies
10 0 9 0
Increase (%) 100 0 0 0
The percent increase was calculated using the following formula:
% increase = (Increase ÷ Original Number) × 100
Table 9: Average Initial And Final Number Of Colonies Observed To The Nake Eye Along With
The (%) Increased For All 3 Trials
No Agent Added Soap Hand Sanitizer Detergent
Initial Number
Of Colonies
(Average)
6.3 0.6 3.6 0.3
Final Number
Of Colonies
(Average)
8.3 0.6 5.0 15.3
Increase (%)
(Average)
37.0 0.0 38.8 1466.0
The average was calculated by using the formula:
(initial number of colonies with no agents added in trial 1
+
initial number of colonies with no agents added in trial 2
+
initial number of colonies with no agents added in trial 3) / 3
This process repeated for the final number of colonies and (%) increase for no agents added, soap, hand sanitizer, and detergent.
Graph 1:
Graph 2: displays values only up to 40 (access link to see)
https://docs.google.com/spreadsheets/d/1hnwnp3QJC1JJ2qirnVlXihPjLDBRpRoIL35Y_Xw3ego/edit#gid=0
Conclusion:
Throughout the course of the whole lab it is possible to notice various trends across the different trials that we performed. In sum the controlled group had a greater number of colonies, which was what we hoped for and also predicted. Another thing that could be observed was that the hand sanitizer didn’t do well, which is also something that could have been predicted based on the background research and all. The one that proved most effective at removing germs and bacteria from the trackpads was soap, which is the most effective at REMOVING germs and bacteria. Detergent worked well, but not as well as we had hoped. Somehow in one of the trials after swabbing the q-tip with the detergent trial the amount of colonies grew out of what we were waiting for and ended up being more than the control group, however this error is something we addressed in the evaluation. One of the weaknesses in our experiment was that we had a limited area to work on. We chose to work on the Macbook’s trackpad, but because of the number of trials that we had to undergo, we would have to use more than one trackpad, and the three different trackpads could and most probably did have different amounts of germs and bacteria on them. We also divided each individual trackpad into three parts, which also could have been uncertainty in the number of germs and bacteria in each separated area. Another weakness was the number of trials. It is recommended by most people that the number of trials for a good and trusting experiment be five but because of our limitations in Petri dishes and objects to measure we were only able to undergo three trials. That could also have added to the level of uncertainty. Finally, another weakness in our experiment was that no one in the group had access to the origin in time of the specific sanitizing utensils that were used in the lab, and that could have affected other steps in the lab report. One thing however that was done fairly well in the experiment was the use of the controlled variables. The correct amount of sanitizing materials were used at all times, the Petri dishes were kept at the same temperature and at a safe location at all times, so that helped a lot in the whole process of the lab. To understand better, Table 2 explains well this process (it is in the identifying variable section of this lab report). Even though three trials were done, which theoretically is a small number and not the recommended, the data that we gathered answers correctly the research question from the beginning. Our group used controlled variables (with no addition of agents) in order to compare with other sanitizing utensils.
- https://docs.google.com/spreadsheets/d/1hnwnp3QJC1JJ2qirnVlXihPjLDBRpRoIL35Y_Xw3ego/edit#gid=0
- https://docs.google.com/spreadsheets/d/1hnwnp3QJC1JJ2qirnVlXihPjLDBRpRoIL35Y_Xw3ego/edit#gid=0
