Rationale:

We will be washing and filtering our Soil B to created an enriched lysate. This is so we will be able to perform a spot test and plaque assay for the Soil B lysate.

Procedure:

• First, we created an aseptic zone on our table using CiDecon and 70% Ethanol. We also lit a ethanol burner to create the aseptic zone
• I then put 2mL of Soil B into a 15 mL conical vial, and added 10 mL of LB Broth
• I then shook the vial for ten minutes, with both my hand as well as the vortex machine
• My vial massed at 17.488 g and was then centrifuged at 10,000 g’s for five minutes
• While my vial was being centrifuged, I needed to begin the preparations for finding the percentage water,  percentage sand/silt/clay in my soil sample, and my soil pH
• To calculate the percentage water, I first obtained a weighing dish and massed it. It weighed 2.39 g
  • I then added soil into the dish, and massed it again. The dish + soil weighed 14.454 g, so the weight of the soil was 12.064 g
  • The dish with my soil sample in it was then placed into a hood to evaporate for 48 hours (Results in next post)
• To calculate percentage sand/silt/clay, I first obtained a 50 mL measurement vial, and added 4mL of soil into it
  • I then added water to the 10mL mark, as well as SDL (Soil Dispersion Liquid) to the vial, and shook for 30 seconds
  • After the 30 seconds, I placed the vial in the hood in a rack to let sit for 48 hours (Results in next post)
• To find my soil pH, i First took a pH vial and added a small amount of Soil B into it
  • I filled the rest of the vial with DI (Deionized) water, and then shook for 10 seconds
  • After letting the soil sit, I placed a strip of pH paper into the vial, and let it react for 45 seconds
  • The recorded pH of my soil was 6.5
• After my soil was centrifuged, I ran my liquid through a top filter (22 μL filter) to get my enriched lysate
• I had around 10 mL of enriched lysate in a 50 mL conical vial; I labeled my vial with my initials and the date, as well as “Soil B”
• I then added .5 mL of arthrobacter and incubated my tube

Data/Observations

My Enriched Lysate prior ro incubation

The soil-water solution with SDL in it; results in 48 hours

The pH vial and pH paper after measuring. My weighing dish can also be seen in the background

• My pH indicated that my soil is slightly acidic; it would be interesting to compare results to others in the lab
• The SDL had already started to work in the 50 mL measuring vial; I could see some distinct separation of materials in the vial

Next Steps:

My next steps would be to perform a spot test or plaque assay with the enriched lysate of Soil B. I will also need to check on the results of the percentage water and percentage sand/silt/clay next lab