Tstl Ee Faustine H S Pta

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Concernant la présentation orale.

La durée est parfaite (5:30 mins)

Il y a quelques erreurs comme "The chewing-gum", "and on health(voir enregistrement)" =} "on our health", "before attempting to found(voir enregistrement) out if…" =} "before attempting to find out if", "experiences" =} experiments, "diapo 4" =} slide 4, "without sugars degrades decomposes in the soil, "A positive witness sample with a piece of paper", "chewing gum was the best for health" =} "chewing gum was the best for your health "

Les phrases suivantes sont mal dites: "For the realisation of our protocol", "The suspension mother make ??? initial suspension four dilution of each", "Between make PCA medium in double nappy.",

Attention à la prononciation de certains mots comme "also", "compare", "sugar", "question", "biodegradables", "kinds", "mouth", "swab", "inoculating", "trace", just CO2 (TWO!)", "high", "environment"

Il faut bien prononcer les "s" à la 3ème personne du singulier et après chaque mot au pluriel : 8 drops

Il y a des mots mal prononcés dans certaines phrases comme par exemple celle-ci :"Some people chew it non-stop every day and throw it on the ground instead of in the bin", ou celle-ci "we noticed that our control tube does not know how to be acidified", ou ici "….more nutritious medium, the MEVAG medium is the one we used. In addition, xylitol has been replaced by sorbitol, so we can see more decisive results"

C'est assez bien présenté et ton texte est assez bien écrit.


Diapo 1 et 2

1 Introduction
Diapo 3
Chewing-gum is the secondmost polluting product in the world. Some people chew it non-stop every day and throw it on the ground instead of in the bin. We may ask ourselves if chewing gum is not harmful to us but alsofor the environment. To answer this question, we will compare two kinds of chewing-gum, with or without sugar.
What impact has chewing gum got on our health and environment?
PROBLEM QUESTION : How we can we limit the impact of chewing-gum on the environment and on our health?

To answer this question we will look at it from many angles before attempting to find out if an alternative form of chewing gum exists to avoid its negative impact.

For the realisation of our protocol, we used two kinds of chewing-gums:
-HOLLYWOOD, product without sugar.
-CHICZA, our product with sugar and too biodegradable.
So, our question who as: would they be there some chewing-gum biodegradables? We can answer yes. Because that we allow to use it in our experiences and to compare it to our other of a chewing-gum.

2 The composition of the two chewing gum

         ◦ Sweeteners (sorbitol, xylitol, sacred)
         ◦ Base rubber
         ◦ Bulking agent (E170) serves as a food preservative
         ◦ Aroma
         ◦ Humectant (E422) is used to make the product shiny or to cover it with a protective coating
         ◦ Emulsifier (sunflower lecithins) is used to stabilize the particle in the mixture
         ◦ Dye (E141)

         ◦ Organic cane juice powder
         ◦ Base rubber
         ◦ Organic glucose
         ◦ Organic agave syrup
         ◦ Organic wild mint flavor

3 Test Sugars
Diapo 4
3.1 Principle
Take a sample of saliva from the mouths of two people using a cotton swab. Then make a suspension in two seperate test tubes with 3 ml physiological water and then dip the swabs into each tubes.
In a MEVAG medium, replace glucose with 8 drops of sorbitol. In both tubes put 8 drops of saccharose. Make a control using glucose. Use an inocculating loop & dip it into the suspension and give an injection central in the two MEVAG. Incubate a 37° during 24H.


3.2 Result
During the first test session, we noticed that our control tube does not know how to be acidified, we concluded that the medium was not nutritious enough. So we took a
more nutritious medium, the MEVAG medium is the one we used. In addition, xylitol has been replaced by sorbitol, so we can see more decisive results with acidification and the presence of bacteria for the sugar test. With these modifications we can
noticed that all the tubes are positive, so the chewing gum leaves traces of sugar on our teeth and in our mouth.

4 Microbiote
Diapo 5
4.1 Principle
The test takes place in pairs, with two chewing-gums. One have sugar and second have no sugar. Two chewing-gum are chewed, and two chewing-gum normal. Using a mortar mash one chewing-gum for make suspension mother with chewed chewing-gum. Make the test with other chewing-gum. The suspension mother make four dilution of each. Incubate in PCA medium that we have sunk. Incubate in 37°C during 24h.
Between make PCA medium in double nappy.

We perform the same protocol with chewing-gum no-chewed. Then, we realize a count on these PCA by comparing depending microbial flora present on agars with or without sugars and chewing-gum chewed or no chewed.


4.2 Result
We see on our graph that chewing gum without sugar has a concentration
most important bacterial. This allows us to see that sugarless chewing gum once
chewed takes a significant amount from the mouth. This helps to understand that it cleans the


5 Blood Agar Test

5.1 Principle
It is a rich environment that allows the cultivation and isolation of demanding bacteria (without the need
particular factors). Reading hemolysis is an orientation criterion, in particular for
streptococci. This will allow us to see if we have bacteria in our mouths.

5.2 Result
We have cultures on our blood agar, it proves that we have bacteria
in the mouth which is from the streptococcus family.

6 Biodegradation of chewing gum
Diapo 6
6.1 Principal
The experience is to see if the chewing gum with or without sugars degrades in the soil. Its takes place in 3 stages.
The first is to put a chewing gum with sugars, a sugarless chewing gum and controls.
A positive witness with a piece of paper and a negative witness with just a floor. A bottle, containing soil and compost, we test positive without soil, just CO2.
In part 2, we make a burette drop with NaOH, in the Erlenmeyer flask and HCL which we put in the burette. This part indicates the basic-acid reaction.
In part 3, we test the NaOH which can be found in an empty bottle compared to the bottle. That we allow to see the emission of CO2. This happens after 4 weeks and 6 weeks.


6.2 Result
We notice a degradation of NaOH, compared to the rate of CO2 found. We notice
that at 5 weeks it is the chewing gum that releases the most CO2. It changes at the
week 6 or our positive witness releases the most. After 8 weeks you can see a
total degradation of our positive control plus CO2 emission. Our two chewing gums in
still free, their degradations are not total.


7 Conclusion 
Diapo 7
During this project, we carried out 3 manipulations which made it possible to respond to our two hypotheses and finally to our final problem. The results of our first test session we
have evolved because they were not decisive enough for the media or microbial concentrations. So on the second test, our results were more conclusive, because we changed all the problems we encountered. Which could lead us to respond to the problem.
Our experience on the degradation of chewing gum has shown us that it can degrade, but this degradation is slow in 8 weeks our chewing gum was still compact. Sure
that we can conclude that chewing gum is a product which takes a long time before disappearing completely from the ground.
For health effects, we have concluded from experience with the sugar test that chewing gum leaves sugar in our mouths, because we have noticed that it develops
with saliva. Then the second, the microbial flora test shows us that chewing gum cleans the mouth in a way, because when it is removed from the mouth there is the presence of microorganisms
on chewing gum. The health effects of our two chewing gums are a deposit of sugar on the teeth, but they also help to cleanse.
Biodegradable chewing gum removes a low concentration of microbial flora from the mouth, but the product after 8 weeks is degraded, but less than our product without sugars. Our sugar-free product removes a high microbial concentration from the mouth, but degrades better. To limit the impact of chewing gum on the environment, compost should be made so that it degrades in the long term. And the health effects we concluded that biodegradable chewing gum was the best for health.
We had as a project that was half done to make a chewing gum compost.

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