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Growth of Bacteria and Fungi


Each of you will be given a Petri dish of sterilized agar and some type of nutrient for bacterial and or fungal growth. You will expose the plate to the air in a setting of your choosing for 10 minutes to 1 hour. You will then place the petri dish in a safe place where it will not be disturbed. Every day for the next month you will photograph and post your images to a Picasaweb album. You will create a subpage from this page and post a slide show with a brief description of the conditions of your plate.

Types of Agar

  • LB: Luria Broth or Luria Agar is a widely used agar in biotechnology. It is the agar of choice for growing recombinant E. coli. (II)
  • NB: Nutrient Broth or Nutrient Agar is a rich agar usually used to cultivate bacteria that do not form their own vitamins. ( )
  • MM: Minimal Medium (yes the same stuff Beadle and Tatum used) contain minimal nutrients and sucrose. (I)
  • EMB: Eosin Methylene Blue agar is a selective agar for gram negative bacteria with lactose sugars it differentiates between organisms that can use lactose and ones that cannot. (Pink/Purple in color)

Your Task

  1. Expose petri dish with agar to the atmosphere in a room of your home or school for one hour
  2. Take a photograph of the Petri dish every day for a period of 1 month.
  3. Try to maintain good lighting, exposure and focus in each photo.
  4. Post your pictures to your own Picasaweb album. Caption each photo Day1, Day 2, etc.
  5. Create a subpage here and post a Picasweb slideshow of your images. Include a brief description of the conditions you exposed and kept your petri dish in.
If you are having difficulty viewing your images in PicasaWeb (Google wants you to use Google+) copy and paste the following link into your browser:

Your Task (Part II)

  1. Download your PicasaWeb Album to the local computer.
  2. Rename your images sequentially, such as bacteria-1.jpg, bacteria-2.jpg, etc.
  3. Open the the application imageJ.
  4. Open your images as an image sequence (file->import->image sequence-> choose folder containing your images)
  5. Process your images for analysis (Mr. Fazio will show you how)
    • Choose to analyze the entire plate
    • or select specific colonies to observe
    • count the unique types of bacteria or fungus you see.
  6. Record data in a Google Spread sheet and graph the results
  7. insert spreadsheet on your bacteria page
  8. Insert graph(s) as images on your webpage
  9. Write a brief conclusion
    • include what type of growth did you observe
    • was the growth exponential or logistic. 
    • did the growth cover the entire plate (if not hypothesize why)
    • anything else you feel is important

ImageJ tutorial

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