User:Student 57/Notebook/Biology 210 at AU

Microbiology and Identifying Bacteria

January 4, 2016

Purpose
To characterize the colonies and cells of the bacterial species found in Transect Four. It was hypothesized that the addition of tetracycline would inhibit the growth of bacteria on the nutrient agar plates.

Materials and Methods
Wet mount slides were prepared from each of the four agar plates, 10^5 dilution of hay infusion culture agar plates with and without tetracycline, 10^3 dilution of hay infusion culture agar plates with and without tetracycline. This was done using a tooth pick to collect a small amount of growth, this growth was put on a slide with a drop of water and a cover slip was placed on top. These samples were observed through a microscope.

A gram stain sample was also created from each of the aforementioned agar plates. For each gram sample, a small amount of growth was collected using a sterilized loop. This sample was placed on a slide with a drop of water. The sample was heat fixed over a flame, rinsed with water, covered with iodine for one minute, rinsed with water, decolorized with alcohol for fifteen seconds, rinsed with water, covered with sanfranin stain for thirty seconds and rinsed with water.

PCR samples were also created with our bacteria. Using samples from the 10^5 serial dilutions for the hay infusion culture, PCR tubes were created. Twenty five microliters of a primer/water mixture were added to two PCR tubes until the beads were dissolved. A small amount of bacteria from the agar plates were added using a toothpick and mixed with the primer. The PCR tubes were left to run in a PCR machine.

Observations and Data

Protists and Algae

January 28, 2016

Purpose
To identify protist and algae samples from the Hay Infusion sample from Transect Four. Describe protist samples and document where in the Hay Infusion ecosystem they came from.

Materials and Methods

The hay infusion culture was created in a jar by adding 10 grams of soil and vegetation from transect four, 500 milliliters of deerpark water, and .1 gram of dried milk. This was mixed for ten seconds and left in the lab at room temperature with the top off for one week. Upon observation the hay infusion smelled a bit of rotting eggs and standing water.The appearance was dark with dirt settled to the bottom.

After a week, samples were taken from two different locations in the Hay Infusion ecosystem. The first niche was shallow and near the surface of the Hay Infusion jar. On the surface there was a thin white film on top of the water, and the sample was pulled just below this surface. The second niche was deeper and close to the flower petal that fell to the bottom of the jar.

Data and Observations

Difflugia, Blepharisma, and Euglena were found in niche one near the surface of the Hay Infusion. Stentor, Volvox, and Arcella were found in the second niche nearer to the plant life in the jar. The organisms nearer to the plant may not be able to photosynthesize themselves, and rely on plants for their energy source.

Volvox meets all the life of needs requirements as described in "Biological Science."

• Energy: Volvox procure energy by photosynthesizing.
• Cells: Each Volvox colony is made of a number of cells.
• Information: Genetic information stored in nuclei.
• Replication: Asexual reproduction.
• Evolution: Ancestors of Volvox became colonies from single cells.

Conclusions and Future Directions
When taking the samples from two separate niches it was hypothesized that different protists and algae would favor certain environments within this ecosystem. Photosynthesizing organisms tended to prefer the niche nearest to the top of the jar, while algae were found nearest to plant matter. Though this is a small ecosystem, it would be expected that similar patterns happen in nature on a much larger scale.

If the hay infusion were allowed to grow for another two months I would expect more distinct patterns of behavior in terms of where they would be found in the jar among protists and algae. If the jar were kept in the lab, I would expect that photosynthesizing organisms would struggle more than if they were in the pond in transect four.

To prepare for next week, a serial dilution of agar plates was done in preparation for the "MIcrobiology and Identifying Bacteria" Lab,

LW

Transect Four January 14, 2016

Location: This transect is located near McCabe on the southern end of American University's campus.

The 20 by 20 foot transect is located on the edge of a courtyard surrounded by buildings. North of the pond, there are two benches on the border of this transect. The southern edge of the transect is closest to a building where outdoor lighting shines into the area. There are two larger trees in the area, as well as smaller bushes and grass. The pond is covered by a net that is constructed with bamboo sticks. The pond itself is man made and constructed of large rocks. To the north of the pond, there is a courtyard with heavy foot traffic.

Topography: There is a pond at the center of the transect. The pond is bordered with rocks. There are two large trees as well as a few smaller trees and bushes.

Biotic components: Pond, trees, bushes, grass, insects.

Abiotic components: Rocks, statues, bamboo covering the pond, net covering the pond.

LW