MILDEW OF THE ORANGES

Objective of the experiment

We want to cultivate the mildew from which penicillin is taken and to see the effect of the temperature on its increase.

Instructions

  • Scour two oranges or two lemons, possibly from biological cultivation, on the floor
  • Close them in two bags.
  • Leave a bag in a warm dark place and the other one in the refrigerator for a week

Observations

The first time after a week both oranges were unchanged.
We remade the test with two biological oranges: after three days the mildew appeared on the orange kept warm, (first of all a zone of the orange had became tender and white, then the spot had extended and had became grey-green).
The orange in the refrigerator was well conserved for six days, then begun to mould.

Conclusions

The not biological oranges have a treatment that prevent the growth of the mildew.
The lukewarm atmosphere favours the increase of the mildew, than appeared soon on the orange kept warm and only later on the orange kept cold . The name of this mildew is "penicillum" because if observed through a stereoscope it appears formed by many small paintbrushes.


School site Aristotle Redi Spallanzani Metamorphosis Microorganisms "The tiny animals"