Results:

Unfortunately, the “KEA 10/5/2018 PA” plate was left on the lab counter, not in the incubator. The “Control KEA LEF 10/5/2018” plate was placed in the incubator. Strange contamination patterns appear on both “KEA 10/8/2018 PA” and the “Control KEA LEF 10/5/2018” plates as shown below.

Rationale:

Another plaque assay will be run with the enriched lysate from soil D to determine whether or not there are bacteriophages in the sample that specifically target Arthrobacter. Another soil sample will be collected incase this sample does not have a phage.

Procedure:

1. Once an aseptic zone was established, 10 μL of “KEA 10/3 FS enriched” was added and mixed into a test tube which already had 0.5 mL of Arthrobacter.
2. 8 mL of LB Broth, 90 μL of 1 M CaCl₂, and 10 mL of 2X TA were combined into a conical vial.
3. Transferred 4.5 mL of the Top Agar mixture from the conical vial into the test tube with the enriched lysate.
4. The test tube mixture was poured into the plate labeled “KEA 10/8/2018 PA.”
5. The “KEA 10/8/2018 PA” plate was placed in the incubator at room temperature.

Observations:

• The following calculations were performed to determine enough LB Broth, TA, and CaCl₂needed for 4 plates.

• Soil E was collected from under a live oak tree by the marina. The pictures below show how the tree was located right by a sewage pipe. Also, it shows how the tree had green moss on its bark.

• It was recorded that the tree had a circumference of 110 cm and a canopy diameter of 533.4 cm. The height was 10.3 m.
• When collecting soil E, it was observed that the marina’s area must be the dirtiest, most polluted part of campus. Many foam cups and other pieces of trash have claimed the area under the bridge as their home. This is shown in the pictures below.

Next Steps:

On Wednesday, if there are plaques, the experiment will proceed with picking a plaque. If there is contamination, another plaque assay will be run on soil D, and soil E will be enriched. If there are no plaques, soil E will be enriched.