Microbes are everywhere.
The experiment performed in the Lab was isolation of microbes taken from us and the environment. We used Nutrient Agar which is a growth medium used to culture microorganisms or small plants and Sabourand Dextrose Agar plates used to cultivate moulds and yeasts. The objective of it was to demonstrate that microbes are everywhere. We expected to find a variety of bacteria, moulds and yeasts. We were introduced to aseptic techniques as they help ensure that only certain microorganisms are present in the plate. These methods also guarantee that microorganisms do not escape from the specific petri dish, contaminating the laboratory and possibly causing disease. Describe features of colonies.
Nutrient Agar plate (N.A.)
Sabaround Dextrose Agar plates (S.D.A.)
4x sterile Swabs
1x Diluent (universal bottle)
Firstly, NA plate was exposed to microbes from me using sterile swabs. The swab was scrubbed inside my nails and then rubbed over ½ of the plate. Secondly, for the environment- the swab was dipped in diluent to moisten and then applied to the drainage pipe from the laboratory. This swab was rubbed over the second half of the plate. NA plates were incubated inverted at 37oC for 48 hours. We repeated the procedure with the SDA plate at 22oC for 5 days. All plates were labelled with our initials, part of the body/environment swabbed, incubation temperature and media used. Results obtained:
Moulds are actually fungi, and they often appear whitish grey, with fuzzy edges. They usually turn into a different colour, from the centre outwards. Examples are shown below: On the right hand side we can see a circular green mould colony and round yeast colonies. Left hand side of the plate shows round bacterial colonies. The dominant colour is cream. However, we can appreciate a round colony in a pinkish colour.
We can see mould colonies in a yellowish colour at the top. However, the handle’s side...
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