Objective : To observe various forms of bacteria in spoiled food or fruit
Instrumen & material :
1. Boiled potato that has been stored in 4 days ( spoiled potato )
2. Coconut juice that has been spoiled 4 days
3. Spoiled cooked rice for 4 days
4. Cow milk that has been spoiled for days
5. 4 glass pipetts
6. 1 tweezer
7. Straigth pin
8. Metylen blue solution
9. Alcohol 70 %
10. 1 spirit lamp
11. Microscop and its equipment
12. Cotton or tissue
Procedure :
1. Cleaning the object glass with cotton ( tissue ) damped in alcohol.
2. Sterilizing the sraigth pins by burn them above the spirit lamp until they smouldered.
3. Touching the spoiled ( boiled ) potato with sterilezed pins apply to evenly to the object glass.
4. Doing the fixation by let it pass through the burning flame three times in a row with an interval of one second.
5. Dropping metylene blue in the bacteria preparation that we have made previously and let it 2-3 minutes.
6. Washing the preparation under draining bottle, until the metylene is vuanished.
7. Drying the prep by exposes it to the air.
8. Observing the bacteria shape under the microscope with strong magnification.
9. Repeating number 1-9 treatment on the spoiled coconut juice, spoiled cooked rice, and spoiled milk.
The result of our observation :
Coconut water
The bacteria of coconut water look like spiral. The spiral looked on the corner of the picture. Its colour is brownish yellow. And in the center of picture, there are some bulge
Spoiled potato
The bacteri of potato look like grapes. It means that the bacteri flock together like grapes. It’s color is blue & gtreen.
Boiled cooked rice
The bacteri of spoiled cooked rice is similar to the bacteria of potato. There are some bulges. It has something like hair in the bulges.
Boiled coconut juice
The bacteri of coconut juice has blue and green colors. The bacteria which has green color flock together but broken by the bacteria which has blue color.
Boiled milk
The bacteria of milk is not flock together in one spot. There are many bulges on this bacteria n several bulges, there are hair. But in other bulges, they don’t have hair.
Answer Of Queston :
- What is the function of fixation in that treatment?
The Funtion of fixation in that treatment is for drying the sample of experiment object (bacteria). So, it can be glue on the preparat. It can help us to get the accurate result of our experiment.
Conclusion :
The bacteria has many kinds of shape, like spiral (coconut water), grape (spoiled potato)., bulges (spoiled cooked rice, coconut juice, spoiled milk).
