In our experiment we looked at E. coli growth to see how antibacterial agents affected it. We examined this through looking at the zones of inhibition as well as looking at the size and number of E. coli colonies. In this experiment garlic was clearly the best antibacterial agent however there are much more things contributing to the results. Now firstly garlic contains allicin which is a known a very powerful antibiotic substance which is released when garlic is crushed or chopped up. The garlic juice which was released from the cheesecloth is dissolved in water quite easily and was very potent so when the liquid diffused throughout the agar in the experiment it was very effective in killing the bacteria and stopping growth throughout the dishes In a study conducted by the University of California Irvine “Garlic juice was tested in the laboratory against a wide spectrum of potential pathogens, including several antibiotic-resistant strains of bacteria. It showed significant activity against the pathogens”(The Editors of Publications Internation:2007:1). Also, “garlic juice still retained significant antimicrobial activity even in dilutions ranging up to 1:128 of the original juice”(The Editors of Publications Internation:2007:1).This could be why garlic still remained incredibly effective despite being watered down and having the filter paper only take a small portion.
The same thing applied to ginger as phenol like ancilin is another strong antimicrobial product but it's no where nearly as potent or effective. A study dubbed “[a] comparison of the antimicrobial activity of garlic, ginger, carrot, and turmeric pastes against Escherichia coli O157:H7 in laboratory buffer and ground beef” found actually that the ginger paste was more effective in environments at 4 degrees so there is a chance that the temperature in the incubator was too high for the ginger to be truly effective as it was set to 37. Unlike garlic, ginger lost its antimicrobial properties when in smaller quantities so under our testing methods ginger was not effective but it usually performs better in other circumstances.
Turmeric is another antimicrobial agent which has been known to be strong however in our experiment the way the solutions were constructed it did not allow for it to live up to its full potential. Tumeric is fat soluable and when something is fat-soluble “that means it dissolves in fat. Without fat, the active component in turmeric, curcumin, has a difficult time making it past the stomach, into the small intestine, and into the blood where it can offer the greatest benefits”(Renter:2014:1). Turmeric requires a fat in order to have some of its components survive in harsher environments in order to be effective.
Turmeric is also not as potent as garlic but is comparable to ginger. This attributes to turmerics failure in our experiment as without a fat and the general difficulty of a powder dissolving inside of water turmeric's effectiveness dwindles. It also had significant E.Coli growth in the plates.
Lastly salt performed poorly similar to turmeric. “Sodium Chloride is better used as a microbial inhibitor which means that it prevents the growth of bacteria since it reduces the amount of water present. Thus the bacteria doesn’t have a chance to grow and flourish as much”(Salt Suite:2012). This was demonstrated in this experiment as salt was able to dissolve better in water than turmeric and henceforth when the water diffused inside the agar the bacterial growth in the plate significantly decreased, as there was less water. However the salt itself was not strong enough to kill the bacteria shown by its lack of a zone of inhibition.
Our data in general did support our hypothesis. The experiment was both reliable as there were absolutely no outliers in the data.The measurements for each substance were very similar in each dish, trial and in total. The overall validity of the experiment is also good as the method tested how the natural remedies were able to prevent the growth of and kill the E.coli. The method saw how the remedies were able to diffuse into the agar and see how effective they were in both killing the e coli judged by the area of inhibition and preventing growth evidenced by the size and number of colonies of E.coli in the plate. There were of course sources of uncertainty when we performed this experiment, firstly the placement of the materials inside of the incubator. As we conducted our experiment in many of our previous trials and attempts at growing bacteria we noticed that the temperature did range in different areas of the incubator. There were areas that were hotter than others as well as areas that were colder than others shown by how fast plates of thin agar dried up, despite all being poured to the same thickness. This could have been a slight factor in changing our results. We tried to control all of our variables however one big variable which was quite hard to control was the placement of the filter papers once they had absorbed the remedy. After they absorbed the remedy there was room for the liquid to run and spill going into the surrounding areas, this could create a false area of inhibition which was basically an extension of the filtration paper. The next source of uncertainty lies in the size of the papers, as they were not all identical. This could have skewed the results slightly but not enough to take away from a noticeable trend in the experiment. The next large source of uncertainty lied in the potential contamination of the agar while the experiment was conducted. Though there were many precautions taken in the experiment like minimally opening the lid and not breathing while the agar was open however there was still chance of contamination when the E.coli was being inoculated and when the filters were being put it. An incredibly large source of uncertainty was concentration of the solutions. This could have made a significant impact on the experiment as rather than creating the best possible version of each substance we made each one equal as to remove the variable of potentially having one substance stronger than the other. This was good for simplicity but it could have negatively impacted the results of their performance. Another source of uncertainty was how some of the areas of inhibition for the garlic were slightly estimated. This is due to the fact the diameters could have gone out of the actual petri dish as some of them were going all the way to the edge. Even if they were slightly bigger it would not make a great change to the results. It would only slightly make garlic stronger. Lastly there really were no events that could have changed the experiment which we would have no control over.
If we were to perform this experiment again there would be a few things which we would slightly alter, Firstly we would conduct more care in general when removing and placing the coffee filters inside of the petri dish as there was room for there to be excess to spill and create false area of inhibition. We would also perform more trials, conducting the experiment 3 times to be sure of any possible outliers. We would also put only one filter in the middle of the petri dish so that the measurements would be exact. This time around that was impossible as we did not have 45 petri dishes. We would also create the best version of each substance by adding oil to the turmeric solution and more salt to the salt solution.
The same thing applied to ginger as phenol like ancilin is another strong antimicrobial product but it's no where nearly as potent or effective. A study dubbed “[a] comparison of the antimicrobial activity of garlic, ginger, carrot, and turmeric pastes against Escherichia coli O157:H7 in laboratory buffer and ground beef” found actually that the ginger paste was more effective in environments at 4 degrees so there is a chance that the temperature in the incubator was too high for the ginger to be truly effective as it was set to 37. Unlike garlic, ginger lost its antimicrobial properties when in smaller quantities so under our testing methods ginger was not effective but it usually performs better in other circumstances.
Turmeric is another antimicrobial agent which has been known to be strong however in our experiment the way the solutions were constructed it did not allow for it to live up to its full potential. Tumeric is fat soluable and when something is fat-soluble “that means it dissolves in fat. Without fat, the active component in turmeric, curcumin, has a difficult time making it past the stomach, into the small intestine, and into the blood where it can offer the greatest benefits”(Renter:2014:1). Turmeric requires a fat in order to have some of its components survive in harsher environments in order to be effective.
Turmeric is also not as potent as garlic but is comparable to ginger. This attributes to turmerics failure in our experiment as without a fat and the general difficulty of a powder dissolving inside of water turmeric's effectiveness dwindles. It also had significant E.Coli growth in the plates.
Lastly salt performed poorly similar to turmeric. “Sodium Chloride is better used as a microbial inhibitor which means that it prevents the growth of bacteria since it reduces the amount of water present. Thus the bacteria doesn’t have a chance to grow and flourish as much”(Salt Suite:2012). This was demonstrated in this experiment as salt was able to dissolve better in water than turmeric and henceforth when the water diffused inside the agar the bacterial growth in the plate significantly decreased, as there was less water. However the salt itself was not strong enough to kill the bacteria shown by its lack of a zone of inhibition.
Our data in general did support our hypothesis. The experiment was both reliable as there were absolutely no outliers in the data.The measurements for each substance were very similar in each dish, trial and in total. The overall validity of the experiment is also good as the method tested how the natural remedies were able to prevent the growth of and kill the E.coli. The method saw how the remedies were able to diffuse into the agar and see how effective they were in both killing the e coli judged by the area of inhibition and preventing growth evidenced by the size and number of colonies of E.coli in the plate. There were of course sources of uncertainty when we performed this experiment, firstly the placement of the materials inside of the incubator. As we conducted our experiment in many of our previous trials and attempts at growing bacteria we noticed that the temperature did range in different areas of the incubator. There were areas that were hotter than others as well as areas that were colder than others shown by how fast plates of thin agar dried up, despite all being poured to the same thickness. This could have been a slight factor in changing our results. We tried to control all of our variables however one big variable which was quite hard to control was the placement of the filter papers once they had absorbed the remedy. After they absorbed the remedy there was room for the liquid to run and spill going into the surrounding areas, this could create a false area of inhibition which was basically an extension of the filtration paper. The next source of uncertainty lies in the size of the papers, as they were not all identical. This could have skewed the results slightly but not enough to take away from a noticeable trend in the experiment. The next large source of uncertainty lied in the potential contamination of the agar while the experiment was conducted. Though there were many precautions taken in the experiment like minimally opening the lid and not breathing while the agar was open however there was still chance of contamination when the E.coli was being inoculated and when the filters were being put it. An incredibly large source of uncertainty was concentration of the solutions. This could have made a significant impact on the experiment as rather than creating the best possible version of each substance we made each one equal as to remove the variable of potentially having one substance stronger than the other. This was good for simplicity but it could have negatively impacted the results of their performance. Another source of uncertainty was how some of the areas of inhibition for the garlic were slightly estimated. This is due to the fact the diameters could have gone out of the actual petri dish as some of them were going all the way to the edge. Even if they were slightly bigger it would not make a great change to the results. It would only slightly make garlic stronger. Lastly there really were no events that could have changed the experiment which we would have no control over.
If we were to perform this experiment again there would be a few things which we would slightly alter, Firstly we would conduct more care in general when removing and placing the coffee filters inside of the petri dish as there was room for there to be excess to spill and create false area of inhibition. We would also perform more trials, conducting the experiment 3 times to be sure of any possible outliers. We would also put only one filter in the middle of the petri dish so that the measurements would be exact. This time around that was impossible as we did not have 45 petri dishes. We would also create the best version of each substance by adding oil to the turmeric solution and more salt to the salt solution.