User:Sirah P. Bah/Notebook/Biology 210 at AU

Microbiology and Identifying Bacteria 02/11/16

Observations of Hay Infusion Culture: Water levels decreased significantly in the culture, and retained a dark brownish/black color. When the lid was opened an odor of rotten eggs. The leaves that were left in the culture were very dark, and looked as though they were beginning to mold. The soil has still settled to the bottom of the container. At the top of the culture there looked to be a semi-permeable layer of much. Dirt was also clamped to the walls of the container.

Serial Dilution Results Table:

Yes there are differences in the colony types between the plates with versus without antibiotic. The plates with agar created much larger dots and there were more spread out. The effect of tetracycline was that these plates displayed dots grouped closer together. This makes sense, because lower dilution= increase colonies, and since tetracycline is an antibiotic, it was trying to kill bacterias.

Mechanisms of Action for tetracycline... Tetracylines performs as a protein synthesis inhibitor, and because of this function it works to kill the 30S ribosome. Can work against aerobic gram positive and gram negative species

Source: Kohanski, M., Dwyer, D., Collins, J. 2010. How Antibiotics Kill Bacteria. Nature

Reviews. 8: 423-425

Bacteria sensitive to tetracycline... Chlamydia, Mycoplasma and Rickettsia http://mmbr.asm.org/content/65/2/232.full

Bacteria Characterization Table:

Materials and Methods for gram stain, DNA isolation, and PCR amplification: First a loop needs to be held over a flame in order to sterilize it, and scare off the bacteria sample to mount. After this to prepare the slide add one drop of water. With a red wax pencil circle where the bacteria was placed. Heat fix the slide, and then rinse with crystal violet for a minute. After the rinse, rinse it with water and perform the same process three more times with gram's iodine mordant, 95% alcohol, and safranin stain while alternating between rinses with water. When the rinses are complete dab the slide dry with a kimwipe, and look at the stain slide under a microscope. For PCR amplification isolate two plates from which the sample will be obtained. Put samples into two separate microbes, and add 20 micrometers of primer. Flick tube around for about 5 seconds, and place the tubes into the PCR machine.

Pictures of colony morphology, gram stains, and motility studies...

--- Sirah Bah ---

"Algae and Protist" 02/4/16 After a week of the Hay Infusion sitting in the lab descriptions of it were able to be made. The dirt and leave fragments settled to the bottom of the container. When the lid was removed from the container an odorous stench of something rotten and putrid emanated. The watery mixture that inhabited the bottle was a dark brown, and cloudy color. The water also displayed a tint of green. At the top there was signs of apparent life, and it looked similar to a brownish mold. Samples of two Niches: The organisms differ close to versus away from the plant matte, because of ecological diversity.

Three organisms observed:

        The protists and the algae present include the gloeocapsa which are motile algae that use photosynthesis for their nutrients. They are 5 micrometers at 40x, and are green. The gloeocapsa were found at the top of the hay infusion. In the middle of the hay infusion Arcella was found. Arcella are circular, white motile algae. The arcella uses photosynthesis as well, and was size 1 line at 10x or 10 micrometers. At the bottom section of the hay infusion were amoeba. Amoeba are large, dark green motile circular protists. They were measured to be 5 micrometers at 10x.
        The gloeocapsa meets all the needs of life as it can reproduce, made up of cells, capable growth and development, maintains homeostasis, and uses energy. If the hay infusion “grew” for another couple of months, a range of changes would occur. I would expect to see great bacteria growth, and the development of new organisms. Some selective pressures that would affect the community of the samples are temperature, humidity, motion (disturbing the habitat), sunlight, and human interference. 

-- SPB--

Transect photos and descriptions: 01/28/16 List of biotic components: Trees, Shrubs, List of abiotic components: Sprinkler system, trash (receipts, cigarette butts), Light post General description: The transect is located on the north eastern end of campus. It is skirted by a sidewalk on 2 of its ends, and borders Ward Building. There is a large patch of dirt that takes up a majority of the transect space. There are several small trees, bushes, and sprinkler systems scattered across the space. There is a large, tall tree in the center of the transect. --- SPB ---