Microbes in the Environment
3. With a pipet, inoculate the agar dish labeled water with the water sample. Use only enough water to cover the top surface of the dish (approximately 4 drops).
4. Cover the dish and let it sit for 30 minutes to ensure the water soaks into the agar.
5. Incubate the dish upside down at room temperature for 24–72 hours.
6. Observe the dish and count the number and types of colonies. Record the results in Data Table 1: Environmental Colony Formation, in the Lab Report Assistant section.
7. Soak the dish in a 10%-bleach solution for 1 hour and then discard it.
Part iii: Microbes in the Soil
1. Choose an environmental site to collect a soil sample. Then use a new sample cup to collect a soil sample.
2. Pour distilled water into the cup, so the water sits just above the soil level. Mix the water and soil well.
3. Let the sample sit until the soil settles to the bottom of the cup.
4. With a pipet, collect a sample of the water layer on top of the soil and inoculate the agar dish labeled soil. Use only enough water to cover the top surface of the dish (approximately 4 drops).
5. Cover the dish and let it sit for 30 minutes to ensure the water soaks into the agar.
6. Incubate the dish upside down at room temperature for 24–72 hours.
7. Observe the dish and count the number and types of colonies. Record the results in Data Table 1: Environmental Colony Formation, in the Lab Report Assistant section.
8. Soak the dish in a 10%-bleach solution for 1 hour and then discard
4. Cover the dish and let it sit for 30 minutes to ensure the water soaks into the agar.
5. Incubate the dish upside down at room temperature for 24–72 hours.
6. Observe the dish and count the number and types of colonies. Record the results in Data Table 1: Environmental Colony Formation, in the Lab Report Assistant section.
7. Soak the dish in a 10%-bleach solution for 1 hour and then discard it.
Part iii: Microbes in the Soil
1. Choose an environmental site to collect a soil sample. Then use a new sample cup to collect a soil sample.
2. Pour distilled water into the cup, so the water sits just above the soil level. Mix the water and soil well.
3. Let the sample sit until the soil settles to the bottom of the cup.
4. With a pipet, collect a sample of the water layer on top of the soil and inoculate the agar dish labeled soil. Use only enough water to cover the top surface of the dish (approximately 4 drops).
5. Cover the dish and let it sit for 30 minutes to ensure the water soaks into the agar.
6. Incubate the dish upside down at room temperature for 24–72 hours.
7. Observe the dish and count the number and types of colonies. Record the results in Data Table 1: Environmental Colony Formation, in the Lab Report Assistant section.
8. Soak the dish in a 10%-bleach solution for 1 hour and then discard