Where do most microbes live?

Celesty Burnett, Keyondra Lowe, Tomara Murray

Introduction

Microorganisms are living creatures that can not be seen with the naked eye. Microorganisms or microbes have been in the world for almost a billion years. Microbes live everywhere. They live in soil, rocks, air, animals, and other places all over the world. Just one teaspoon of soil contains over 1,000,000 bacteria and over 120,000 fungi. Wherever there is water there are microbes. Most microbes need water to live. There are many watery environments and they include: saltwater and freshwater environments, places with three times the salt concentration of the ocean, open oceans, slime pumps, and places with few nutrients. Microbes also live in aerated streams that have lots of oxygen and murky bogs that have no oxygen. Ponds have a wide variety of microbial life. Light and oxygen change at different depths and this makes different habitats for different microbes. For example, you can find green algae and cyanobacteria at the very top of the pond and in the dark lower parts, you can find sulfate producers and methanogens.

Microbes live in grass too. Grass has cellulose and cellulose in the number one fuel for microbes. Microbes are everywhere and we want to see where we can find the most.

This experiment was developed to find out where the most microbes would be found in three given environments. Microbes are everywhere, but there are more in some places than others. The three environments we tested were grass, pond water, and a counter top in a laboratory. The experiment showed that there were more microbes in pond water than the other two environments. We predicted it would be this way based on the amount of nutrients and habitats found in pond water.

Materials

 Procedure

Soil Sample

  1. First, take 1 gram of soil and place it in a 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this vial soil/grass sample. Shake the vial well to mix up the contents.
  2. Take a 1ml pipette and extract 1ml of the solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:10.
  3. Take a 1ml pipette and extract 1ml of the 1:10 solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:100.
  4. Take a 1ml pipette and extract 1ml of the 1:100 solution and place it in a third, clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:1000.
  5. Without contaminating the dilution, take a pipette and attract 1ml from the 1:1 dilution. Squirt this on a fresh nutrient agar plate and smear the dilution over the plate with a loop.
  6. Cover the plate and allow the dilution to soak into the gel. After the dilution has absorbed turn the plate over so that the organisms can multiply. On the bottom side of the plate, label it 1:10 with a black sharpie.
  7. Store the plates in an incubator for 24 hours.
  8. Repeat step 2 for the 1:100 and the 1:000 dilutions.
  9. Duplicate steps 1-3 so that there will be a total of six plates.

Pond Water Sample

  1. First, take 1 ml of pond water and place it in a 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Shake the vial well to mix up the contents.
  2. Take a 1ml pipette and extract 1ml of the solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:10.
  3. Take a 1ml pipette and extract 1ml of the 1:10 solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:100.
  4. Take a 1ml pipette and extract 1ml of the 1:100 solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:1000.
  5. Without contaminating the dilution, take a pipette and attract 1ml from the 1:10 dilution. Squirt this on a fresh nutrient agar plate and smear the dilution over the plate with a loop. Cover the plate and allow the dilution to soak into the gel.
  6. After the dilution has absorbed, turn the plate over so that the organisms can multiply. On the bottom side of the plate, label it 1:10 with a black sharpie.
  7. Store the plates in an incubator for 24 hours.
  8. Repeat step 2 for the 1:10 and the 1:00 dilutions.
  9. Duplicate steps 1-3 so that there will be a total of six plates.

Counter Top

  1. Take a wet q-tip and swab 10cm2 area of the counter top of a laboratory bench. Place the q-tip in a clean 15ml vial and fill the vial up with 10ml of water. Shake the vial and its contents well.
  2. Take a 1ml pipette and extract 1ml of the solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:10.
  3. Take a 1ml pipette and extract 1ml of the 1:10 solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:100.
  4. Take a 1ml pipette and extract 1ml of the 1:100 solution and place it in a clean 15ml vial. Fill the vial up with water until it reaches the 10ml mark. Label this dilution 1:1000.
  5. Without contaminating the dilution, take a pipette and attract 1ml from the 1:10 dilution. Squirt this on a fresh nutrient agar plate and smear the dilution over the plate with a loop.
  6. Cover the plate and allow the dilution to soak into the gel. After the dilution has absorbed, turn the plate over so that the organisms can multiply. On the bottom side of the plate, label it 1:10 with a black sharpie.
  7. Store the plates in an incubator for 24 hours.
  8. Repeat step 2 for the 1:10 and the 1:00 dilutions.
  9. Duplicate steps 1-3 so that there will be a total of six plates.

Conclusion

In conclusion we found out that our hypothesis was correct. The pond water had an average of 184.5 microbes, the grass had an average of 113.8 microbes, and the counter top had an average of 9.16 microbes. So over all, the pond water had the most and the counter top had the least.