User:Maeve Alterio/Notebook/Biology 210 at AU
February 16th, 2014 Lab 3
This lab, Microbiology and Identifying Bacteria with DNA, was to understand the characteristics of bacteria including drug resistance, and to understand how DNA sequences are used to identify different species. There is expected bacterial and fungal growth on the agar plates, however Archaea is not expected to grow as they are “extremophiles” and the conditions were average.
Procedure: Part 1: Quantifying and Observing Microorganisms - obtain the handout describing colony morphology as well as your plates. - Count the number of colonies on each plate Part 2: - Using the plates as well as the agar plates to evaluate the antibiotic resistance of the colonies Part 3: - obtain a prepared slide and classify the different types and shapes of bacteria - pick two colonies from the agar plate and one from the tetracycline plate. - Make a wet mount of the colonies and observe under a microscope using both the 10x and 40x objectives. - Next, gram stain the three colonies so that it will be easier to identify. - Observe the gram stained slides under the 40x objective. Part 4: - Transfer a single colony of bacteria to 100 ul of water in a sterile tube - Incubate for 10 minutes at 100C then spin in centrifuge.
Data: Hay Infusion: Still pungent smell, however no fungal layer at the top. Water is darker in color as well as there is a ticker layer of dark foliage on the bottom of the jar. The appearance or smell may change week to week due to the different growth rates of the different organisms.
Table 1: 100-fold serial Dilutions Results Dilution Agar Colonies Counted Conversion Factor Colonies/ml 10-3 nutrient Apx 400 (lawn) 103 400,000 10-5 Nutrient 168 105 16,800,000 10-7 Nutrient 11 107 110,000,000 10-9 Nutrient 0 109 0 10-3 Nutrient + tet 350 103 350,000 10-5 Nutrient + tet 1 105 100,000 10-7 Nutrient + tet 0 107 0
There were obvious differences in the two types of plates, nutrient agar as well as the nutrient agar and tetracycline plates. There were more colonies on the nutrient plate. This indicates that the antibiotic worked and killed some of the bacteria. Tetracycline is a broad range antibiotic produced by the Streptomyces genus. It works by inhibiting protein synthesis. Its common uses are to treat bacterial infections such as urinary tract infections, gonorrhea, and chlamydia. There are many different species of bacteria that are not affected by tetracycline.
Conclusion This lab helped to give a better idea on bacteria, as well as understanding antibiotic resistance. For further study I would isolate colonies from the agar plate and plate them on tetracycline plates.
Attempt 3 for lab 2 due February 6th February 6th, 2014
Introduction: The purpose of this experiment was to get familiar with a dichotomous key, a key that helps identify any group of organisms. The other objective of this experiment was to understand the characteristics of different algae and protists.
Process: In the first part of this lab, we were given two known organisms. After making wet mounts of the two different organisms, we were to characterize them as well as use the key to identify the organism. In the next part of the lab, we were instructed to take three samples from within our hay infusion and observe two different types of algae or protists in the sample. We collected from three different locations, the surface of the water, right against a leaf, and right by the mud. This should theoretically give very different species due to the location. Each location varies in regards to light amount, as well as food source. Finally, the last part of the experiment was to prepare and plate a serial dilution. We took the samples and diluted it 10-2, 10-4, 10-6, 10-8. We plated our samples on two different plates, normal plates as well as on tetracycline plates. We then left the plates to incubate for a week.
Data: Hay Infusion: the hay infusion was settled, with the mud on the bottom, along with composted leaves and twigs. There was what appeared to ne a fungal layer coating the top of the water, as well as a pungent earthy odor. Had this been given a longer period of stagnation, there would be significantly more growth as well as a variety of species.
Name Characteristics Slide 1: A gonium Large sphere, 37.5 um Slide 1: B Colpidium Larger, lighter than other, colorless, medium body, covered in cilia 50um Slide 2: A Bursaria Truncatella White, cilia present, oval, large body with large mouth. 400um Slide 2: B Didinium Cyst Little to no movement. 17.5 um Slide 3: A Stentor Many small dots, colored, dark blueish. 50 um Slide 3: B Colpidium Colorless, cilia present, oval shaped, small body, fast swimmer, 50um, darker than other
Conclusion: In this lab, we were able to successfully identify some of the different microbes present in our transect. For future study, I would suggest more tests on the organisms found in the transect. This would give a clearer understanding of the organisms present.
2/6/14, lab 1
Good job!! Some notes:
-Make sure you include pics from lab 1 and lab 2 by Sunday
-Try pressing "enter" two times to insert a break between paragraphs and lists.
-Start working on building a map of your transect to detail your land and where your samples are taken from. We will talk about this more Wednesday
January 31, 2014 Biological Life at AU Introduction The purpose of this study was to identify different types of algae as well as observe our transect which we would be studying. In order to become comfortable with identifying organisms under a microscope, we observed Chlamydomonas, Gonium, and Volvox. We then observed our transect and collected samples that we would later test. Process First, we observed three different types of green algae, Chlamydomonas, Gonium," and "Volvox. After gathering the data on all three members of the Volvocine line, we left the lab and went to collect data as well as samples from our transect. Finally after collecting data, we set up our hay infusion cultures. Data Characteristics Chlamydomonas Gonium Volvox Number of Cells 18 10 4 Colony size 7.5 μm 17.5 μm 200 μm Describe any functional specializations of cells flagella Moved quickly Flagella, pilli Describe any reproductive specialization isogamy isogamy oogamy
cell specialization occurs mostly in multicellular organisms as they are able to carry out different tasks without compromising the vitality of the organism itself. The three genera have specialized their abilities to their environment. Evolution does not always move towards and increased complexity, in the case of the algae, it is which organisms and which traits are most suited to their environment and therefore have a better chance of passing their traits on to the next generation. Part 2: Transect 5 Biotic components: -holly tree -dead sycamore tree -pine trees -leaves -ivy -grass
Abiotic components: - soil - air -light -minerals -rocks
Transect: Transect five was off campus located at the nearby seminary. The transect was located on a downward slope with a building off to the left, a statue behind it, and a communal area in front. The transect had three trees, a holly tree, a pine tree and a dead sycamore tree. The ground had a thick covering of ivy as well as decomposing leaves and pine needles. Just to the left of the dead sycamore tree was a fallen branch.
Conclusion Although the three types of green algae we looked at were different, there was a surprising amount of variation in the size, shape and function of each type of algae. Each species had a different size, motility, and different characteristics. Looking at the different types of algae will come in handy when analyzing the different organisms collected in the transect.
January 22, 2014 Successfully entered my first post. Maeve Alterio