GAANT Chart

GAANT Chart

Poster

Poster

Annex B - Multimedia Presentation

Video

Video Link: http://www.youtube.com/watch?v=wm8pzR2iVf8

Acknowledgements

 Acknowledgements

The S2-05 ISS Group A have taken efforts in this project as a group. However, it would not have been possible without the kind support and help of many individuals. We would like to extend our sincere gratitude to all of these individuals.

We are highly indebted to our mentor, Mr Charles Low, and our lab supervisor ,Ms Su, for their constant guidance which led to the completion as well as the success of the project. A crucial advisor to our group on the project, Mr Charles Low has been a trusted person capable of answering our doubts or questions regarding the project. We would like to especially credit him on commenting us the structure of data analysis. We would also like to thank Ms Su for paving the path of the project for our group by giving us her constant supervision and providing necessary information pertaining the project.
In addition, we would like to express our very great appreciation to the school for supporting us in our project by supplying us the resources and equipment needed. On top of that, we are thankful to the school for offering us this rare opportunity to work on this kind of science-related project work.
Finally, our thanks and appreciations also go to the students of class S2-05 for their help in sharing important information pertaining to the task given.

Bibliography

Bibliography


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Conclusion

Summary of findings
Firstly, data was particularly drawn from the 10^-3 dilution set compared to the rest of the other sets due to it having the most number of fixed statistics in its dependent variable for each beverage. This makes it the most reasonable and accurate dilution set for this experiment, which supports the reason that data should be mainly derived from this set (10^-3 dilution set).
Also, we came to know more on the growth competency of L.casei on the various beverages tested. Based on the results, milk encourages L.casei growth best and coke deter L.casei growth worst among all the beverages. We are able to rank these beverages in ascending order of its effectiveness in growing L.casei , with cola being the least suitable, followed on by energy drink, continuing with sterile water, then tea, with LB Broth next, then coffee and finally, milk being the most suitable beverage.

1. Cola: L.casei bacteria colonies averaged at 0 CFU/ml for both tests. Additionally, based on previous or other dilution sets, had an overall average of 0 CFU/ml, which meant its results were consistent.
2. Energy drink: L.casei bacteria colonies averaged at 0 CFU/ml for both tests. Additionally, it averaged 10 CFU/ml for 10^0 dilution set, which meant its results were also consistent
3. Sterile water: L.casei bacteria colonies averaged at 0 CFU/ml for both tests. However, this was contrary to previous dilution sets where it averaged TMTC for 10^0 dilution set.
4. Tea: L.casei bacteria colonies averaged at 8 CFU/ml for both tests. In addition, it also had several middle range statistics for 10^0 dilution, 10^-2 dilution, and 10^-4 dilution sets with averages of TMTC, 127 CFU/ml, and 1 CFU/ml respectively.
5. LB Broth: L.casei bacteria colonies averaged at 239 CFU/ml for both tests. Moreover, it also had several proportionate statistics for 10^0 dilution, 10^-2 dilution, and 10^-4 dilution sets with averages of TMTC, 1491 CFU/ml, and 45 CFU/ml respectively.
6. Coffee: L.casei bacteria colonies averaged at 3185 CFU/ml for both tests. Besides, it had statistics that were almost in proportion, for 10^0 dilution, 10^-2 dilution, and 10^-4 dilution sets with averages of TMTC, 1720 CFU/ml, and 154 CFU/ml respectively.
7. Milk: L.casei bacteria colonies averaged at 3781 CFU/ml for both tests. Also, it had consistent results of proportion, for 10^0 dilution, 10^-2 dilution and 10^-4 dilution sets with averages of TMTC, TMTC, and 569 CFU/ml respectively.

After much discussion, we deduced that cola allowed zero L.casei growth due to the high contents of [caffeine] in it. Likewise, we believe that the energy drink also allowed low numbers of L.casei growth because of the presence of [caffeine] in it. On the other hand, our guess of why milk turned out to be the most effective beverage in encouraging the growth of L.casei is because milk contain the natural sugar, lactose, of which Lacti acid bacteria like L.casei feed on or ferment to convert these sugars into lactic acid. This allowed the growth of L.casei as the lactose in the milk provided food, or rather a substance required in the natural process of fermentation.

Practical Applications
 However, this project does not just stay in the lab, but is also capable of practical applications in the real world. From the results of this project, we are able to prove that certain beverages like milk are fit for consumption with probiotic drinks while some are not, like cola and energy drinks. Additionally, there is one more group where the effects of it on L.casei are very minimal and insignificant. Then, we are able to use this prove to use it practically.
First and foremost, we are able to give important, supported advice to probiotic drink manufacturers to state in their prescription which beverages to consume with or not to take with. This would, in a way, inform the consumers of these probiotic drinks to know how to take them. Ultimately, this would minimize complications caused by the effect of certain beverages on the probiotics in our gut flora.
In addition, we can convince governments to encourage companies manufacturing beverages to limit their ingredients to more probiotic-friendly ones. With this, the commonly consumed beverages will be more compatible with the probiotics in body, particularly Lactobacillus, which will eventually lead to the reduction of hazards towards human health.
Lastly, another example would be to raise awareness of this issue of the effect of common beverages on probiotics on the general public itself via public efforts like events or science fairs. This would educate the public on the selection of beverages at certain times and the frequency of it. With this efforts, more people would be aware of what happens when a certain beverage gets ingested, especially its interaction with probiotics in the stomach flora.

Areas for further study
There were many areas that we could have pursued our project on, if only for a longer time period given. Continuation of the project into areas of experimenting each individual beverage more in-depth on the reasons why they inhibit or aid the growth of L.casei (Example: moving down to a substance in the beverage that influences this effect). Also, carrying on of the project into retesting certain beverages with contradicting results on different sets if not all to ensure reliability and accuracy of results. On top of that, the expanding in the diversity of the independent variable (the type of beverages) could also be done. This would allow a larger diversity of beverages to be tested, which in turn, allows more data to be produced to be used eventually in practical application.
First, the continuation of the project into areas of experimenting each individual beverage more deeply on the reasons of them inhibiting or aiding the growth of L.casei simply refers to identifying a potential substance inside the beverage and testing it. By testing it, we are able to look for relationships of different beverages with the similar substance and their effects on the growth of L.casei. An example would be the cola set narrowed down to testing caffeine instead to confirm that caffeine was the root cause of the effect of L.casei not growing with the beverage cola.
Secondly, the carrying on of the project into retesting certain beverages with contradicting results on different sets if not all to ensure reliability and accuracy of results means to having retests for certain beverages with inconsistent results in different dilution sets. Still, this can result in the entire set being repeated. This retesting of certain beverages would produce more reliable results as it improves the consistency and figures out the problem the test is facing. An example would be having a retest for the set with sterile water because of its inconsistent results of having an average of TMTC for 10^0 dilution and an average of 0 for the remaining sets.
Thirdly, expanding the diversity of the independent variable (the type of beverages) relates to having more than just seven beverages used for the experiment. This meant that more types of beverages will be tested and increases the reach of the project, which covers more topics, bring in more benefits due to the increased potential of having more practical applications or use.

Discussion

Key findings
In the results, there were many dilutions. We would use the 10^-3 dilution to compare due to the fact that it has the least TMTCs and would be the most reasonable and accurate to compare the data between the various beverages. Basically, ALL COMPARISONS would be done in the 10^-3 dilution.

We will go over results of each of the beverages individually.

1. Coffee
In 10^0 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-2 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-3 Dilution, there was an average of 3185 lactobacillus colonies grown on the MRS plates.
In 10^-4 Dilution, there was an average of 154 lactobacillus colonies grown on the MRS plates.
Compared to Milk, Coffee had an average of 3185 lactobacillus colonies grown on the MRS plates while Milk had 3781. A difference of 596 colonies. (Milk has more)
Compared to Sterilized Water, Coffee had an average of 3185 lactobacillus colonies grown on the MRS plates while Sterilized Water had none. A difference of 3185 colonies.
Compared to Tea, Coffee had an average of 3185 lactobacillus colonies grown on the MRS Plates while Tea had only an average of 8 colonies. A  difference of 3177 colonies.
Compared to LB Broth, Coffee had an average of 3185 lactobacillus colonies grown on the MRS Plates while LB Broth had only an average of 239. A difference of 2946.
Compared to Cola, Coffee had an average of 3185 lactobacillus colonies grown on the MRS Plates while Cola had none. A difference of 3185 colonies.
Compared to Energy Drink, Coffee had an average of 3185 lactobacillus colonies grown on the MRS plates while Energy Drinks had none. A difference of 3185 colonies.

2. Milk
In 10^0 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-2 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-3 Dilution, there was an average of 3781 lactobacillus colonies grown on the MRS plates.
In 10^-4 Dilution, there was an average of 569 lactobacillus colonies grown on the MRS plates.
Compared to Coffee, Milk had an average of 3781 lactobacillus colonies grown on the MRS plates while Coffee had 3185. A difference of 596 colonies. (Milk has more)
Compared to Sterilized Water, Milk had an average of 3781 lactobacillus colonies grown on the MRS plates while Sterilized Water had none. A difference of 3185 colonies.
Compared to Tea, Milk had an average of 3781 lactobacillus colonies grown on the MRS Plates while Tea had only an average of 8 colonies. A  difference of 3773 colonies.
Compared to LB Broth, Milk had an average of 3781 lactobacillus colonies grown on the MRS Plates while LB Broth had only an average of 239. A difference of 3542.
Compared to Cola, Milk had an average of 3781 lactobacillus colonies grown on the MRS Plates while Cola had none. A difference of 3781 colonies.

3. Sterile Water
In 10^0 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-2 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-3 Dilution, there were no lactobacillus colony growth on the MRS Plates.
In 10^-4, there were no Lactobacillus colony growth on the MRS Plates.
Compared to Coffee, Sterile Water had no lactobacillus colony growth while Coffee had an average of 3185 Lactobacillus colony growth. A difference of 3185 colonies.
Compared to Milk, Sterile Water had no lactobacillus colony growth while Milk had a average of 3185 Lactobacillus colony growth. A difference of 3781 colonies.
Compared to Tea, Sterile Water had no lactobacillus colony growth while Tea had an average of 8 Lactobacillus colony growth. A difference of 8 colonies.
Compared to LB Broth, Sterile Water had no lactobacillus colony growth while LB Broth had an average of 239 Lactobacillus colony growth. A difference of 239 colonies.
 Compared to Cola, both of them did not have any Lactobacillus growth. There were no difference.
Compared to Energy Drink, both of them did not have any Lactobacillus growth. There were no difference.

4. Tea

In 10^0 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-2 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-3 Dilution, there was an average of 8 lactobacillus colonies grown on the MRS plates.
In 10^-4 Dilution, there was an average of 1 lactobacillus colonies grown on the MRS plates.
Compared to Coffee, Tea had an average of 8 lactobacillus colony growth while Coffee had an average of 3185 Lactobacillus colony growth. A difference of 3177. (Coffee has more)
Compared to Milk, Tea had an average of 8 lactobacillus colony growth while Milk had a average of 3781 Lactobacillus colony growth. A difference of 3773.
 Compared to Sterilized Water, Tea had an average of 8 lactobacillus colony growth while Sterilized Water had none. A difference of 8 colonies. (Tea has more)
Compared to LB Broth, Tea had an average of 8 lactobacillus colony growth while LB Broth had an average of 239 Lactobacillus colony growth. A difference of 239 colonies.
Compared to Cola, Tea had an average of 8 lactobacillus colony growth while Cola had none. A difference of 8 colonies. (Tea has more)
Compared to Energy Drink, Tea had an average of 8 lactobacillus colony growth while Energy Drink had none. A difference of 8 colonies.

5. LB Broth
In 10^0 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-2 Dilution, the lactobacillus colonies grown on the MRS plates were too much to count.
In 10^-3 Dilution, there was an average of 239 lactobacillus colonies grown on the MRS plates.
In 10^-4 Dilution, there was an average of 45 lactobacillus colonies grown on the MRS plates.
Compared to Coffee, LB had an average of 239 lactobacillus colonies grown on the MRS Plates while LB Broth had only an average of 239. A difference of 2946.
Compared to Milk, LB Broth had only an average of 239 while Milk had an average of 3781 lactobacillus colonies grown on the MRS Plates. A difference of 3542.
Compared to Sterlized Water, LB Broth had an average of 239 Lactobacillus colony growth. while Sterilized Water had none.. A difference of 239 colonies.
Compared to Tea, LB Broth had an average of 239 Lactobacillus Colony growth, while Tea had only 8. A difference of 231 colonies. (LB Broth had more.)
Compared to Cola, LB Broth had an average of 239 Lactobacillus Colony growth while Cola had none.
Compared to Energy Drink, LB Broth had an average of 239 lactobacillus colony growth while Energy Drink had none. A difference of 239 colonies.

6. Cola
In 10^0 Dilution, there were no Lactobacillus colony growth on the MRS Plates.
In 10^-2 Dilution, there were no Lactobacillus colony growth on the MRS Plates.
In 10^-3 Dilution, there were no lactobacillus colony growth on the MRS Plates.
In 10^-4, there were no Lactobacillus colony growth on the MRS Plates.
Compared to Coffee, Cola had no lactobacillus colony growth while Coffee had an average of 3185 Lactobacillus colony growth. A difference of 3185 colonies.
Compared to Milk, Cola had no lactobacillus colony growth while Milk had a average of 3185 Lactobacillus colony growth. A difference of 3781 colonies.
 Compared to Sterilized Water, both of them did not have any Lactobacillus growth. There were no difference.
Compared to Tea, Cola had no lactobacillus colony growth while Tea had an average of 8 Lactobacillus colony growth. A difference of 8 colonies.
Compared to LB Broth, Cola had no lactobacillus colony growth while LB Broth had an average of 239 Lactobacillus colony growth. A difference of 239 colonies.
Compared to Energy Drink, both of them did not have any Lactobacillus growth. There were no difference.

7. Energy Drink
In 10^0 Dilution, there were no Lactobacillus colony growth on the MRS Plates.
In 10^-2 Dilution, there were no Lactobacillus colony growth on the MRS Plates.
In 10^-3 Dilution, there were no lactobacillus colony growth on the MRS Plates.
In 10^-4, there were no Lactobacillus colony growth on the MRS Plates.
Compared to Coffee, Energy Drink had no lactobacillus colony growth while Coffee had an average of 3185 Lactobacillus colony growth. A difference of 3185 colonies.
Compared to Milk, Energy Drink had no lactobacillus colony growth while Milk had a average of 3185 Lactobacillus colony growth. A difference of 3781 colonies.
 Compared to Sterilized Water, both of them did not have any Lactobacillus growth. There were no difference.
Compared to Tea, Energy Drink had no lactobacillus colony growth while Tea had an average of 8 Lactobacillus colony growth. A difference of 8 colonies.
Compared to LB Broth, Energy Drink had no lactobacillus colony growth while LB Broth had an average of 239 Lactobacillus colony growth. A difference of 239 colonies.
Compared to Cola, both of them did not have any Lactobacillus growth. There were no difference.

Explanation of Key Findings
We would explain the results of each beverage individually.

1. Coffee. The reason why there were so much Lactobacillus growth on the MRS Plates after being put with Coffee is that there were milk in the Coffee.
Lactobacillus is one of the Lactic Acid Bacteria. These Lactic Acid bacteria are found in fermented food and probiotic products. (Lactic Acid Bacteria, 2013, Wikipedia) And the fact that when we consume the probiotic product, the Lactobacillus is still there, it shows that the Lactobacillus can thrive in milky conditions.
2. Milk. As said above, Lactobacillus thrive in Milky Environments, and thus they can survive, and in fact grow and multiply in conditions like Milk.
3. Sterile Water. Everything was going fine for Sterile Water until 10^-3 dilution. As the word implies, Sterilized is about killing all fungi/bacteria. This means that Sterilized Water does not contain any Bacteria/Fungi, or any nutrients for the Lactobacillus to survive on. We guess that when we first put the Lactobacillus into the Sterilized Water, there were a lot of Bacteria inside. As time went by, the Lactobacillus did not have nutrients to survive and eventually died. This was our prediction since we did 10^-2, 10^-3 and 10^-4 later than the one we did on 10^0.
4. Tea. There were too much to count amount of bacteria for Tea when it was in 10^0 dilution. As the dilution increased the amount of lactobacillus colonies decreased. The reason for this is because as dilution implies, it is the reducing of concentration in the chemical. Thus, the concentration of the bacteria decreased and as the amount of dilution increased, the amount of concentration decreased and hence there were less bacterial colonies.
5. LB Broth. LB Broth itself is a nutrient for bacteria. However, Lactobacillus does not seem to grow on it and its effectiveness on cultivating bacteria is not that high. However, as it contains nutrients, it is a suitable environment for the Lactobacillus to grow in and thus, there were an satisfying amount of Lactobacillus while put in LB Broth.
6. Cola. According to Greenwood(2011), said in her survey, Caffeine kills bacteria and sometimes can be stronger than an antibiotic. Cola contains caffeine and might have inhibited or killed of the Lactobacillus in the solution. Due to the caffeine in the Cola, the caffeine might have affected the growth of Lactobacillus.
7. Energy Drink. Similarly, Energy Drinks contains caffeine and would affect the Lactobacillus similarly as it affected the Cola. Energy Drinks also contains other chemicals that might have affected the growth of Lactobacillus colonies.
In overall, the factors that affected the amount of Lactobacillus grown in the MRS plates for the various beverages was decided by the ingredients in the beverage in question. For the beverages that contained different ingredients, the amount of Lactobacillus grown varies.

Evaluation of hypothesis
Coming back to our hypothesis, we predicted that :All of the tested beverages would affect the Lactobacillus. Casei bacteria, but the petri dishes which comprised of beverages other than sterile water in them would cause there to be an average of 30% less colonies than the plates which only sterile water.
From our experiment and results, it is not that accurate.
For Sterile Water, there was no growth in Lactobacillus colonies. It is like it can be compared to Cola and Energy Drink, which both also do not have growth in their respective MRS Plates. However, MIlk and Coffee had a very big increase in Lactobacillus, compared to Sterile Water.
Compared to LB Broth, it is a bit more accurate. However, it is still shocking that the Milk and Coffee values were so high.
From this( Our experiment results), we can conclude that Cola and Energy Drinks would inhibit the growth of Lactobacillus Casei, and that it is not healthy for consumption together with probiotic drinks.
For Milk and coffee however, there was a positive effect, and benefited the Lactobacillus Casei.
Referring to our hypothesis, the amount of Lactobacillus for Milk and Coffee is obviously 30% more than the controls, Sterilized Water and LB Broth. Also, for Cola and Energy Drink, both of them had 30% less bacteria than our control, LB Broth. Which affects too much.

Areas for improvement
The areas of improvement in our tests are as follows:

1. Bacteria from microtubes (containing mixed solution of L.case and beverage) were used over the span of weeks and this bacterial health and count could have deteriorated over multiple freezes. These host microtubes with beverages mixed with lactobacillus (of 0% dilution) from lesson 4 and follow on diluted microtubes from later dates were used, then transferred back into the freezer for later reference. This freezing undoubtedly have helped maintain the bacterial growth status of the bacteria in the microtubes by slowing down life processes occurring inside. However, this freezing does not stop these processes. Therefore, the freezing, itself, would definitely have killed of a certain percentage of bacteria. Consequently, the numbers of living bacteria in each plate could vary unexpectedly from earlier tests and later tests. If results were to be cross-compared, the tests that were taken last would have been most likely to have the results with the least living bacteria to earlier tests. However, these bacteria terminated are usually of small percentages and their effect are usually insignificant. Moreover, this is by far the most feasible method of lab preservation.

2. Contents in perishable food (beverages) like milk are prone to spoilage and beverage spoilage could affect the experiment as there is a change beverage’s contents. As a result, levels of other factors (of decomposition) are increased, which includes bacteria, mold, yeast and enzymes. Even with constant refrigeration, these beverages are capable of becoming spoiled due to having a fixed shelf life, thus creating inaccurate results and ultimately, an unreliable experiment. We can solve this problem by conducting the experiment efficiently within the beverage’s shelf time with little refrigeration for preservation and little intervals in between.

3. For the tests involving the 100 and 1000 dilution sets, the accuracy of the results and consistency of the procedure were reduced as we were able to only do two repeat sets for each beverage for both dilution sets. This meant that there were only two sets to find an average instead of three in previous tests. This failure to carry out a full three sets was due to a mistake made when doing one of the dilution sets, but we only troubleshooted and rectified the error later. As a result, several MRS agar plates had already been wasted, which lead to this eventual deficit and lack MRS agar plates. We should be more carefully in the future and not allow this careless mistake to happen again.

4. As the entire experiment was hinged on the mixture of the 3 Lactobacillus colonies and sterile water which formed the original mixture and the basis of our experiment, any errors would have been voided and nullified the entire experiment. Therefore, we could instead have had redone the entire experiment from the start 3 times to ensure the highest chances of getting accurate results.