User:Sarah Jo Sleiman/Notebook/Biology 210 at AU

Lab Day: 1/29/16 Entry 3

Hay Infusion Observations Our Hay Infusion consisted of rocks, twigs, leaves, grass, soil, and flowers. After two weeks, we observed it a second time after being diluted in dried milk and deer park water. The smell has gotten more foul and rotten. We suspect that it will continue to get worse and more moldy not only due to the time left in a jar, but also due to any bacteria left in the jar.

Serial Dilutions (Table 1)

Procedure II: Antibiotic Resistance To prepare the serial dilution, we took 10 mL of broth and pipetted into four tubes. 100 µL of the Hay Infusion culture was micropipettes into the tube labeled 10^-2 and shaken. 100 µL of that solution was pipetted into the tube labeled 10^-4. After shaken, 100 µL of that solution was pipetted into the tube labeled 10^-6. Finally, 100 µL of that solution after shaken was pipetted into the tube labeled 10^-8. 8 Agar plates were obtained, all labeled either 10^-3, 10^-5, 10^-7, or 10^-8. Four of which were tetracycline positive and four of which were tetracycline negative. Next, 100 µL from the tube labeled 10^-2 were pipetted onto and spread onto the blood agar plates labeled 10^-3 that were both tet + and txt -. This was repeated transferring 100 µL from 10^-4 to 10^-5 (nutrient agar), 10^-6 to 10^-7 (nutrient agar), and 10^-8 to 10^-9 (blood agar). After being kept at room temperature for a week, we observed the colonies and noticed that without antibiotics, there were more bacteria on agar plates. There were only 1 colony observed on one of the plates and a lot of colonies on others (as shown from the table above and the pictures below). The blood agar displayed a foul smell and more tiny colonies than any of the other agar plates. In general specific bacteria that are sensitive to tetracycline include Chlamydia, Mycoplasma, and Rickettsia.

Bacteria Cell Morphology Observations Wet Mounts and Gram Stains were made in order to observe the organisms from the serial dilutions. In order to make a wet mount, we sterilized a loop over a flame to then scoop up a sample of the colony from the agar plates (shown below). After creating a slide they were observed with a microscope. The Gram Stain was created by sterilizing a loop over a flame and scraping samples from the colonies on the agar plates and placing water on the slides. After

Lab Day: 1/22/16 Entry 2

After a week, my lab partners and I observed our Hay Infusion. It was not as diluted as other groups' jars; it contained a very dark brown color. However, similar to many other groups, our jar had a very foul smell. The dilution itself consisted of 10.87 g of samples from our Transect, 0.1 g of dried milk, and 500 mL of DeerPark water. We then took samples from the Hay Infusion itself in order to observe any protists or algae present under a microscope. The layers we chose to pull our samples from in order to make wet mounts were the bottom later and the top later since they would seem to have very different organisms. Using the dichotomous key, we were able to identify a few of the organisms we saw through the microscope. The organisms we found in the bottom zone consisted of Stentor, Colpidium, and Phylum chlorophyta (green algae). In the top zone, Blepharisma, Arcella, and Amoeba were found. The Stentor was a bluish green color and appeared to having an elongated, trumpeted body shape. The Colpidium was caught moving on video. Moving fast across the slide, Colpidium had a round shaped, tiny body with a hook like mouth. The green algae was similar to an Arcella in the round shape, however, it was noticeably green and did not have any globs around it or the brown color like the Arcella we identified in the top zone. Blepharisma appeared as the color purple from the slide and is quite similar to the Colpidium in shape. Lastly, we found an Amoeba that would move occasionally but almost "creeped" across the slide. The size of the Amoeba was not big whatsoever. At the end of lab, we prepared and plated Serial Dilutions for next week's lab from the Hay Infusion. We took samples from the Hay Infusion and pipetted them into sterile broth, which had the dilutions of 10^-2, 10^-4, 10^-6, and 10^-8. Afterwards, we micropipetted the Culture onto four nutrient agar plates and four nutrient agar plus tetracycline plates, which all had different dilutions (i.e. 10^-3, 10^-5, 10^-7, and 10^-9). We did this so that in next week's lab we will be able to see the bacteria from the Hay Infusion divide to form colonies on the agar plates.

Initial Recordings:

Ocular View of Slide:

Colpidium:

SJS

Sarah Sleiman Bio II Lab Section 8 January 15, 2016 Transect 4

The transect observed is located near Gray Hall at American University. It consists of abiotic life (non-living things) and biotic life (living things). The abiotic life observed included 6 benches, several red wires weaving in and out of the soil, rocks (surrounding water and used as a pathway), a statue, a sign, a bucket, a plaque, nets, a few sprinklers, and a sewer opening. The biotic life consisted of numerous trees, bushes (both barren and flower-filled), grass (both dry and well watered), soil, leaves and acorns. Although there were no animals present when observing the transect itself, twigs at the bottom of the trees show possible signs of bird's collecting for nests. In addition, the many acorns, some broken and others in tact, are signs of squirrel presence.

After observing the transect, an aerial drawing was made to replicate such observations. In addition, samples (i.e. rocks, leaves, acorns, twigs, flowers, grass) from the transect itself were collected and taken back to the lab to conduct a Hay Infusion. Along with the 10.87 g sample, 0.1 g of dried milk and 500 mL of DeerPark water were combined in order to perform the Hay Infusion, which was shaken and left in the lab with the lid off over the course of a week.

Attached below are the aerial drawing of the transect, pictures taken from the transect site, and a picture of the Volvocine Line, which was conducted after the Hay Infusion was combined, based off of microscopic observations of Chlamydomonas, Gonium, and Volvox.

SJS