Tstl Ee Ethan M S Pta

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Appréciation

Concernant la présentation orale.

La durée est un peu courte (4:01 mins au lieu de 5 mins!),

N'oublie pas de bien prononcer le morphème –ed : "…we decidee to have….", "can probably be explained "

Les phrases suivantes sont mal dites "a first group which make some cruets falls????", "this experiment made the burette falls with first 5 millilitres…", "We also made taste of conventional and organic apple juice to the students of the class",

Certains mots sont mal prononcĂ©s dans cette phrase "……calibrated the NaOH solution with oxalic acid"

Quelques erreurs Ă  Ă©viter : "the pulpit pulp of an organic

Attention Ă  la prononciation de certains mots comme "crushed", "added", "diluted", "minus", "these", "used", "allowed", "confirmed", "changed", "us", "know", "types", "analyse", "phenomenon"

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

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

Apples

The goal of the Project

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The apple and the most cultivated fruit in France . We know that the apple is composed of more than 70 million bacteria contained in the tail, the seeds and the calyx. There are 20 000 varieties of apples in the world divided into 5 families: the greedy, the perfumed, the balanced, the rustic and the tonic.

The market of the bio market has largely increased since about ten years in the world and does not cease increasing. Different products are offered to consumers and mainly fruit and vegetables.

The market for organic products has increased significantly over the last ten years or so in the world and continues to grow. Various products are offered to consumers, mainly fruit and vegetables. We then asked ourselves:

How is the microbiota of organic apples different from the microbiota of conventional apples?

Is the yield of organic apples lower than that of conventional apples?

We then met with an arboriculturist in our area. This approach allowed us to come to our problem which is :

How does the microbiota of organic and conventional apples affect the preservation, taste and processing of apples?

  • Different storage conditions depending on organic and conventional apples and their environment influence them (room temperature, refrigerator).
  • The treatment influences the conservation of the apples.
  • The taste differs according to an organic apple or conventional.
  • The microbiota differs in organic apples and conventional apple and changes according to the environment in which they are found.

State of progress :

We have carried out a first test session, where we have seeded several growing media. After observing these boxes, we were able to count them and found that the microbiota of organic and conventional apples was almost identical.

To continue our study we then put an organic and a conventional apple in the refrigerator and at room temperature in the dark. This will allow us to know if the microbiota changes according to the method of conservation, and over

First sceance test

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On the one hand, we started to peel the different apples (organic and conventional) to recover 10 g of skin and 10 g of core. We then placed the peelings in two different bags with 90 mL of tryptone salt which we crushed with a stomacher for 3 minutes . This allowed us to obtain the stocksuspensions. We then diluted these suspensions up to 10-3 .

We inoculated the PCA , MRS , M17, Sabouraud , Baird Parker, CFC, VRBG agars with the 10-2 and 10-3 dilutions. Then our group placed all the media to be incubated at 37 degrees for 24 to 48 hours except MRS and M17 which we placed in the garden.

Second test session:

In order to be able to carry out the second test session and answer our problem, we placed during the first test session, an organic and a conventional apple in the refrigerator in the dark and an organic and conventional apple at room temperature in the dark. We then made a stock suspension with these apples, which we diluted to a 10-3 dilution and then inoculated them on the same agars as before. This second test session will allow us to determine if the microbiota of the apples has changed according to their storage time and the environment in which they have been stored and thus answer our problem.

Collective session:
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For the collective session we decided to have a first group which make some cruets falls. After having calibrated the NaOH solution with oxalic acide , the group in charge of this experiment made the burette falls with first 5 millilitres of organic and conventional apple juice and after with the pulpit of an organic and conventional apple previously crushed with 90 millilitres of tryptone salt. After adding the 5 millilitres, this group added a few drops of thymol blue to the measuring flask and filled the cruets with the calibrated NaOH .This experience will show us which apple between conventional and organic is the most acidic

A second group made stock suspensions with the skin and pulpit of the organic apples which were stored in a garage for about 2 months. This group then diluted these two suspensions to a 10-3(ten power minus 3) dilution. Later they inoculated the M17 and PCA media with the 10-2 (ten power minus two)and 10-3 dilutions. (Ten power minus 3)

This group has also seeded organic and conventional apple juice with these two media.

The third group did the same experiment as the second group except they used the conventional apples and apple juice.

This test session allowed us to determine if the apple microbiota had changed since the last time and confirmed our hypothesis that the microbiota of conventional and organic apples had changed.

We also made taste of conventional and organic apple juice to the students of the class.This experience allowed us to know the difference in tastes between these two apple juices
For the collective session we decided to have a first group which make some cruets falls. After having calibrated the NaOH solution with oxalic acide , the group in charge of this experiment made the burette falls with first 5 millilitres of organic and conventional apple juice and after with the pulpit of an organic and conventional apple previously crushed with 90 millilitres of tryptone salt. After adding the 5 millilitres, this group added a few drops of thymol blue to the measuring flask and filled the cruets with the calibrated NaOH .This experience will show us which apple between conventional and organic is the most acidic
A second group made stock suspensions with the skin and pulpit of the organic apples which were stored in a garage for about 2 months. This group then diluted these two suspensions to a 10-3(ten power minus 3) dilution. Later they inoculated the M17 and PCA media with the 10-2 (ten power minus two)and 10-3 dilutions. (Ten power minus 3)
This group has also seeded organic and conventional apple juice with these two media.
The third group did the same experiment as the second group except they used the conventional apples and apple juice.
This test session allowed us to determine if the apple microbiota had changed since the last time and confirmed our hypothesis that the microbiota of conventional and organic apples had changed.
We also made taste of conventional and organic apple juice to the students of the class.This experience allowed us to know the difference in tastes between these two apple juices

After carrying out experiments and waiting for the development of bacteria, we counted everything and here are the results.There is indeed a difference in the number of bacteria present in the two types of apples and apple juice.
We will now analyze the results. We see that on the M17 media whether in the heart, on the skin or in apple juice, when it is organic there are more colonies than when the apple is conventional
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Now, with PCA, we observe exactly the same phenomenon on different parts of the apple and even apple juice.
r%C3%A9sultat%20Pca.PNG
This phenomenon can probably be explained by the fact that conventional apples are treated with pesticides to precisely avoid contamination by bacteria. This therefore allows a higher yield.
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