User:Tyler L. Faulkner/Notebook/Biology 210 at AU

Tetracycline is an antibiotic first discovered in 1940 to treat different types of bacterial infections. Tetracycline has revealed that it can inhibit growth of microorganisms, including those that are either gram-positive or gram-negative, including chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites (Chopra & Roberts, 2001). However, although tetracycline is used to treat many different bacterial infections, it still has a resistance to many growing pathogenic bacteria. Many researchers have found that the increase in bacterial resistance is because new genes are created and code for energy-dependent efflux of tetracyclines (Chopra & Roberts, 2001). Since many pathogens are now resistant to tetracycline, researches are now trying to find other ways to treat infectious and noninfectious diseases.

Hay Infusion Culture:

Our transect is the garden at the northwest side of campus near the tennis courts. Many of the vegetation there now is dead or has weeds growing in their planters. However, many of the planting boxes do have labels of what type of crop is grown there. For example, some that we saw was lettuce and cauliflower. Abiotic factors: sunlight, soil, water, temperature, moisture, wind Biotic factors: worms, birds, other organisms, weeds

When we opened up our Hay Infusion Culture, surprisingly our culture did not smell bad. In fact, it smelt like fresh soil and natural. At the bottom of our jar was the buildup of dirt and on top was the water. On the top layer, we did not notice any type of mold or green shoots, however there was an apparent thin layer on the top of our water.

Pictures of our Hay Infusion Culture:

After using our dichotomous key we discovered Colpidium was present on the bottom layer of our culture. It wasn't very big, and was actually only 50μm. The top layer also had a Colpidium and was 30μm. The Colpidium colpoda are ciliate protozoa, who are commonly found in freshwater environments. We assume that the Colpidium were found in our transect because it is a vegetable garden and with freshwater and soil. In the middle layer we found a Euglena, which was much larger than the Colpidium found in both the bottom and top layer. The Euglena measured 450μm. Euglena are flagellate protists and are very small and long. They are unique organisms because they are to some sorts a combination of both a plant and animal, which causes them to fall in between the Animal and Plant Kingdom. However, because of this very hard distinction, scientist have place them in the Protist Kingdom.

Serial dilution procedure:

After conducting our serial dilution we found that the plates with the tetracycline inhibited the growth of bacteria better than the plates without. When comparing the same dilution level between the agar plates with just nutrients and the ones with nutrients and tetracycline there is a huge difference between the amount of colonies that grew there. A majority of our colonies grown on the agar plates were the same shape on both the plates with and without the tetracycline.

Table 1: 100-fold Serial Dilutions Results

Dilution	Agar Type	# Colonies on Plate	Conversion Factor	Colonies/mL
10^-3	Nutrient	134	x10^3	134,000
10^-5	Nutrient	55	x10^5	5,500,000
10^-7	Nutrient	23	x10^7	230,000,000
10^-9	Nutrient	21	x10^9	21,000,000,000
10^-3	Nutrient + Tet	3	x10^3	3,000
10^-5	Nutrient + Tet	1	x10^5	100,000
10^-7	Nutrient + Tet	0	x10^7	0
10^-9	Nutrient + Tet	0	x10^9	0

Pictures of our Serial Dilutions:

Table 2: Bacteria Characterization

Colony Label	Plate Type	Colony Description	Cell Description	Gram + or Gram -	Additional Notes
10^-3	Tetra	Flat, White, Coccus, Smooth/Glistening	Sarcina, Circular, Motile	Gram +	On this agar plate there were only 2 colonies found
10^-5	Tetra	Flat, White with a tinge of yellow, Coccus, Smooth/Glistening	Coccus, Circular, Motile	Gram -	On this agar plate there was only 1 colony found
10^-3		Milky White/Yellow/a few blue colonies, Punctiform/Flamentous colony, A majority of the colonies were smooth/Glistening, Some rough/slightly raised colonies	Streptobaccilli, Very grouped together, Motile	Gram +	On this agar plate there were many different types of colonies that were grown. Some were spread out and others were very close and compact. At the top of the plate there was also what appeared to be a slight lawn forming.
10^-7		Beige/White, Blue, Circular colony, Flat, Smooth/Glistening	Diplobacilli, Very close together, Motile	Gram -	On this agar plate there were a few different colonies grown. We found only one dark black/blue colony that also grew.

Figure 1: 10^-3 + T At 10x Magnification

Figure 2: 10^-5 + T At 10x Magnification

Figure 3: 10^-3 At 10x Magnification

Figure 4: 10^-7 At 10x Magnification

References:

Chopra, Ian., & Roberts, Marilyn. "Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance". Microbiology and Molecular Biology Reviews 65.2. Jun. 2001. PMC. (4 Feb. 2016) <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC99026/>