How long would it take for bacteria to overtake an object?(read details)?

for example, i have a half loaf of bread, regular whole wheat bread. i place the fresh half loaf of bread into a microwave.


If i wanted the half loaf to be totally covered in a mold in 24 hours at least, what temperature would be advisabel to acheive this goal.

How long would it take for bacteria to overtake an object?(read details)?
I doubt that you can get the bread to be totally covered in mold (which is not a bacterium, by the way) in 24 hours, because mold doesn't grow that quickly.





One of my students did a similar experiment with oranges. She washed them with bleach, exposed them to the air for a few minutes, and then sealed them inside plastic bags to see what would happen. It took more than a week to actually see any mold growing.





Why are you planning to put the bread inside the microwave? To see if microwaves are full of mold spores, or to prove that mold spores can be killed by microwaves?
Reply:The first answer is correct. Putting bread within a microwave would not be a great idea. This will only take the water out of the bread and drying it up and making unsuitable temperatures for the any organism to grow.


But if you want to do an experiment on bacteria growth, you can easily do it on a small scale size first and then get larger.


Supplies/protocol:


*Buy a petri dish and agar plate kit from a local hobby store or toy store. (assume the plate and other supplies are sterile).


* Set up to agar plate and let it harden. You need a bacteria source: you can use an old sponge or under your arm pit. Then scarp your stick (should come with the kit) in a squiggling pattern (start at center and get larger strokes outward. Then rotate the plate and repeat until plate has made a 360deg. rotation).


*Stick a plate within a 37deg. C heat source (body temp. of body (optimum temp. for bacteria growth)). Let that grow for about a few days (keep it in a dark place.


* Measure the amount of time for one white colony to grow.


Measure the area of the plate and measure the size of the colony.


*Use Calculus to find the time using the of the size of the plate, size of colony, and rate of growth of colony.


**Use the exponential equation for the mathematics.


You may need to do a few experiments to find out the actual numbers.





This should be a good exercise in mathmatics and microbiology.


good luck.