... OFFICIALLY POOPED!!

This week started of pretty hectic. On Monday, we performed DNA extraction, rated our radiation plates, and test our starch plates for amylase hydrolysis. I got a bit aggravated because we seemed to be moving slower than molasses. However, I am grateful now because I have a better understanding of DNA extraction. Anyways so we rated our radiation plates, and for some reason we do not have as many contaminants as we usually! That’s a plus! From the observations we noticed that we have a variety of different strains of species. The colors ranged from white-beige-pink-black! Most growth occurred at 0 kGy, however, there was no growth present at 16 kGy. For this reason I believe that some of the strains may be Blastococcus (those that are semi-resistant) because some were able to withstand 6 kGy of radiation. The trend was as expected, as the radiation increased, survival decreased! Next, we checked our starch plates for amylase hydrolysis. This was done by adding iodine to our starch plates. Those strains which were able to hydrolyze amylase produced a “zone of hydrolysis” around the colonies formed. This is a clearing around the bacteria. Most test positive, which leads me to believe that we are dealing with a lot of M. multiseptatus, G. obscurus, and B. jejeunsis! Athough, everything went smoothly, we were not able to perform the test on 3 of our strains, because a certain someone from our group did not parafilm the plates so the bacteria dried out! Finally, we performed DNA extraction which took us FOREVER! We chose 12 strains to work with from our soil sample (LRH-03-1). Once again we found colonies which were orange, peach, cream, white, pink, and black. This symbolizes the presence of a lot of different organisms! Although we left well after time, this was a pretty productive lab I must say! So, I went home to re-live lab all over again! I CONTINUED to study for the midterm; however, I did not feel prepared. Low and behold Cristi sent a study guide, which was extremely helpful. I now vow to put forth much more effort into this class!! So, the day of the test came, and everyone was nervous. I think that the test was challenging but nothing unmanageable if you studied like you should! Anyways, we went on to perform pH test, which included streaking our strains on pH plates of 4, 5, 6, 7, 8, 9, and 10. There was 6 strains assigned to each plate!

Below are the plates from Monday, which shows that as radiation increased growth size decreased.

Also, the starch plates represent strain 30 and 45. 30 shows amylase hydrolysis, whereas 45 did not hydrolyze amylase!

Strain 45:

Strain 30: